Acoustic Zen Crescendo MkII floorstand 3w Transmission-Line speakers

AZ06 SF CRES
NZ$ 37,995.00 pr (incl. GST)
Acoustic Zen

"Music No Compromise"

New
The Acoustic Zen Crescendo is a reasonably  large (1270mm-tall), three-way, five-driver, transmission line-loaded loudspeaker that it is on the one hand a true full-range design yet that manages, on the other hand, to offer a delicate, refined, and highly focused—much like a top-tier two-way monitor. In short, the Crescendo seems to track with the scale of the music, sounding “big” only when the music calls for expansiveness and dynamic power." Absolute Sound loves them, you will too!

Stereo Mojo CES 2014 report:

Triode and Acoustic Zen teamed up again producing the best sound we've heard from the pairing ever. Acoustic Zen Crescendo speakers now in Mk. 2 version. Sounded much improved over last time...maybe the amps....but...This was one of the best sounding rooms in Vegas!
 * CES - Las Vegas High-End Audio Show award:
 * Jimmy Award for Insane Performance by Audio Beats
 * Jimmy Award for Sane Pricing by Audio Beats
 * Best Sound (cost no object) by The Absolute Sound 

Reviewers summary quotes beautifully capture some of the essence of the mighty Crescendo: 
“…offering more than a small taste of ne plus ultra performance: finely drawn treble, meaty midrange, taut, deep bass, and surprising large-scale dynamics.” .....The Audio Beat,  T.H.E. Newport 2012 Report

“…The sound was exceedingly warm and inviting… when music was played at optimal levels, the sound was lovely.”  .....Jason Victor Serinus, Stereophile, T.H.E. Show Newport

“… one of the show’s best sounds despite the price disparity between the Crescendo and the other best of show contenders.” .....Robert Harley, The Absolute Sound, T.H.E. Show Newport 

The sound was simply spellbinding. I can't recall hearing imaging this good on any system using conventional speakers for less than US$100,000” .....Sound Stage, CES

“…This is the gear we take home to our long-suffering families and loved ones and they finally say, ‘Wow. I get it now."  .....Confessions of a Part Time Audiophile, Newport

“The resulting sound was breathtakingly natural. It flowed with ease and grace, pouring out the best sound I have heard at any audio show—and I have been to plenty.” .....John Broskie, Tube CAD Journal, RMAF 

“The Crescendos eminently musical and supremely well-integrated from top to bottom and is currently my favourite box speaker under US$30k. Make no mistake about it: The Crescendo is a fantastic value at its asking price. An enthusiastic five-star recommendation! .....Dick Olsher, The Absolute Sound,

"I do not want to proceed further without these speakers.... And so stay they will, exactly where they now reside; at the heart of my listening and mastering universe....a place where simple pleasure often is second to the hard work of evaluating gear, including scrupulous assessment of my own recordings. I do not want to live without the Crescendos and so I wont."........ Jim Merod - Positive Feedback 

"ROBERT LEE'S  Crescendo" speakers have given me a new inspiration to create music on the highest level I can conceive. They are in a class by themselves.  Not only do they provide great listening experiences.  They bring music closer to my heart and soul.  Quite literally, they place me inside the soundstage where music is recorded so that I feel as if I am right there --  with myself as I hear my own recordings and, no less, with Duke Elington and Beethoven symphonies. Musicians usually are among the last to own great speakers. Finally, with the "Crescendo" speakers, I'm no longer an outsider to my own musical reality. These ACOUSTIC ZEN speakers are a true blessing.  Thank you Robert and the team at Acoustic ZEN! 

…….Mike Garson
   YAMAHA PIANO RECORDING ARTIST
   former - DAVID BOWIE colleague,  classical composer and jazz pianist
   "WILD OUT WEST,"  the Mike Garson Trio double album on BluePort Jazz  recorded live in Virginia City, Nevada
The incredible Acoustic Zen Crescendo speakers, Full Range, tight realistic sounding 20hz bass, 90db efficiency, tube friendly design-run great on 20 watt 845 tube SET's, and excellent on high power quality Solid State amps. They are regularly demoed internationally highly sucessffully with both the New Ayon Triton-PA KT150 stereo power amp and Triode TRX-M845 SE mono blocks, with these Crescendo speakers there is a synergistic match made in heaven match! We have both amps available for your maximum auditioning pleasure.          

For all those that have heard/enjoyed the RAVE REVIEW Acoustic Zen Adagio, well, we know those are real good.. the Crescendo takes that musicality, and goes in every direction into another league all together.. more resolution, bass tightness and DEEEEP extension, room filling concert sound, any volume level.. these speakers are not even heard, they just present the live musical event in the room with you and get out of the way.. this new tweeter is amazing, mids, super fast, clean, VERY LOW DISTORTION SPEAKER... so playing loud is effortless, efficiency makes low volume listening sound full.. and normal mid volume levels are VERY engaging! Music lovers hearing them keep saying things like, "I heard 52,000$ speakers that don't sound this good!"    

These speakers are scary dynamic, in a good way, as in really sounding live! Very versatile, room friendly, wife friendly, amp friendly, and being compared to the best out there but these are way less money. All drivers face forward, **Excellent Transmission Line Bass, port faces forward as well. Coherent, and emotionally engaging.  

These walk the line , providing the ultimate balance of warmth, detail, speed, and harmonic realism!Micro AND Macro dynamics galore...  This is a world class speaker at reasonable pricing! Beautiful, classy, refined, tons of natural detail yet superbly musical. Live dynamics,,, true real Full range!If you are ready for a high end full range speaker that is incredibly diverse,

Features

Specifications

Reviews

Videos

Features

Design: 3 way TRANSMISSION LINE 
Tweeter:   1x” custom Horn loaded RIBBON 
Midrange: 2x Custom 5" with UNDERHUNG COIL 
Woofer:    2x Custom 8" with UNDERHUNG COIL  
Will run great on just about any amp... flexible, diverse...room friendly, amp friendly, wife friendly.
Wood Finsh options:

Specifications

Design: 3way 5driver Transmission line 
Freq. Response: 20Hz to 30kHz ( +/- 3 dB) !! 
Crossover: 3rd order (Linkwitz/Riley) 
Tweeter: 1x  horn loaded Custom RIBBON 
Custom 2x Midrange: 5"” w/underhung voice coil (two) 
Woofer: 2x Custom 8”" w/underhung voice coil (two) 
Impedance: 6 Ohms nominalAvg. 
Efficiency: 90 dB SPL @ 1 meter !!  
Run great on just about any amp... flexible, diverse...room friendly, amp friendly, wife friendly... 
Power Handling: 20 - 200 watts RMS per channel 
Size: 1270 x 280 x 432 mm 
Weight: 62.5 kg each

Reviews

Should the Acoustic Zen Crescendo MkII be your last speaker?
Robert Lee (Acoustic Zen Designer / CEO)

Look at some of the accolades we’ve received in the audio press.

“…the Best System at a Real World Price, was provided by the noble Robert Lee of Acoustic Zen. His voluptuous Crescendo Mark II speakers ($18,000 per pair) simply disappeared, leaving an invisible vocalist in the room to caress the ears with velvet pleasure.” Jim Saxon, The Audio Beat, February, 2014, CES “Jimmy Awards”

“The Crescendo is eminently musical and supremely well-integrated from top to bottom and is currently my favorite box speaker under $30k. Make no mistake about it: The Crescendo is a fantasticvalue at its asking price. An enthusiastic five-star recommendation!” Dick Olsher, The Absolute Sound, January, 2013

 “…The sound was exceedingly warm and inviting… when music was played at optimal levels, the sound was lovely.” Jason Victor Serinus, Stereophile, T.H.E. Show Newport 2012

 “…The sound was simply spellbinding. I can't recall hearing imaging this good on any system using conventional speakers for less than $100,000” Sound Stage, CES 2012 Report

The world of high-end loudspeakers can be a maddening and sometimes rocky place to traverse. Many audiophiles continuously search for a speaker that will satisfy their needs only to continuously discover that over time, a speaker may become fatiguing, uninteresting, or simply intolerable to listen to. Unfortunately, this can also come with a heavy price tag, even up to the six figure range. So, what if you could find a loudspeaker that actually fulfilled the high-end promise of smooth, full range frequency response, time and phase alignment that creates superb images in space, with vanishingly low distortion and gorgeous finishes all at a price that is within the reach of most music lovers? That loudspeaker is here today!

The Acoustic Zen Crescendo has been received at shows around the country, on dealer floors, and in our customers’ homes by audiophiles, reviewers and pundits with incredible acclaim. In its new MkII version, those accolades are even greater. But, how do we get such exceptional sound quality in the first place? The answer is in a design that utilizes solid technologies and techniques that serve the musical waveform first and foremost. Let’s face it, there are lots of high quality loudspeaker designs in the high-end, so what exactly makes the Crescendo different from the rest of that packed landscape? 

First and foremost, the Crescendo was designed for music and with real, live music as the reference. The reality is that most audiophiles and music lovers spend time with their systems listening to music, not thunderstorms or train whistles. Musical signals are highly complex and reproducing them effectively is not necessarily as easy as it may seem. But, with properly utilized technology, design principals and exhaustive testing it is possible to create a transducer that is faithful to the musical signal. The Crescendo accomplishes full range response along with low distortion, dynamic impact, coherence, efficiency, and realistic imaging.

The drivers utilized in a quality speaker design are its heart and most important component. To ensure a solid foundation we have consistently utilized “under-hung” driver technology in our designs. The principal of the under-hung driver is that the voice-coil is narrower than most conventional drivers’ voice-coil and essentially never leaves the magnetic gap of the motor assembly. Basically, the voice-coil is shorter than the magnet’s gap or “under-hung”. The vast majority of speakers utilize the opposite or “over-hung” drivers where the voice coil easily travels beyond the magnetic gap of the magnet assembly because it is longer than the magnet’s actual gap. Think about when you were back in junior-high science; remember playing with magnets? Specifically, the demonstration where you took a bar magnet and placed it under a sheet of white paper and sprinkled some iron filings on top of the paper. When the filings were in close proximity to the magnet, they were more orderly and you could make out the magnetic lines of flux and the further away from the magnet the iron filings were the more disorderly they became. The principal of an under-hung driver is much the same. Since the driver’s coil is always inside of the magnetic gap of the speaker’s motor assembly, it’s under the influence of the magnet across its entire range and it’s response has less distortion, kind of like the bar magnet experiment. With over-hung drivers, the coil travels beyond the magnetic gap and causes distortion in its movements, much like the iron filings that are too far away from the influence of a magnet. The advantage to the under-hung driver is vastly lower distortion since the coil is always under the influence of the magnetic gap and how it is influenced by the incoming signal voltage. That being the case, why don’t more manufacturers utilize under-hung driver technology to achieve lower distortion designs? Well, there are a couple of reasons; one is expense and the other is that over-hung drivers are easier to work with. Essentially, with a conventional, over-hung driver the tolerances and materials do not have to be as rigid and any anomalies in the response and distortion properties can usually be ameliorated with crossover tweaks and cabinet construction techniques. With under-hung drivers, the expense is greater and the need for very careful matching of components and materials is critical, but the outcome more than compensates for the diligence required in their use. That’s why the Crescendo’s mid-bass and bass drivers are all under-hung designs to gain the lowest possible levels of distortion and pass the benefits to the listener. And, in the new MkII, our drivers now feature larger magnet assemblies and we’ve improved the coil to gap ratios due to improved manufacturing capabilities enabling even lower distortion and consequently, greater fidelity!

As you look at the front of the Crescendo, you will see that the upper drivers are in a “D’Appolito MTM” configuration. This allows the best possible recreation of the original waveform and eliminates the “lobing” effect common with other configurations. The advantage to this is that the audio signal will reach the listener in proper phase and time relationships with no smearing due to the signal interactions inherent in conventional designs.

Traditional driver placement vs. MTM design

Two five inch mid/bass drivers that employ a unique magnesium alloy impregnated paper cone material flank a horn loaded ribbon tweeter specifically designed and manufactured for the Crescendo. This MTM array asures smooth frequency response with proper phase and time relationships intact and the ribbon tweeter is implemented to provide extended, open, and non-fatiguing response. An aluminum ribbon covers 95% of the vibrating area of the tweeter membrane. This unique feature provides a purely resistive impedance which means a friendly load for the amplifier and simplifies crossover design.  The vibrating element is almost completely weightless compared to traditional dome type tweeters. This affords immediate and precise high-end response to transients in the musical signal and reveals the dynamics of instruments with high frequency specrtral content like no other. It has an essentially linear phase response which provides time coherent reproduction resulting in accurate frequency  response, rhythmic drive and outstanding imaging capability. Our tweeter is quick, without distortion  and without ringing. Many modern “audiophile” speakers seem to have tilted up or bright treble response which lends a bit of excitement to the sound, but long term causes listener fatigue and dissatisfaction with the overall tonal balance of the speaker. The Crescendo’s mid to high end response is natural, non-fatiguing and remains faithful to the source. 

To convey deep bass with resolution and authority, dual eight inch, ceramic coated, underhung drivers are transmission line loaded to extend response to a true 20 Hz. Low frequency driver “loading” is the engineering process that allows the driver to vibrate freely and at the same time not be adversely affected by nor affect the other parts of the design. There are three basic ways to load a low frequency driver; ported (or vented), acoustic suspension and transmission line. Ported designs are ubiquitous because they are easier and cheaper to design, but usually have high roll-off characteristics - 24dB/octave or more - and don’t lower the resonant frequency optimally, consequently creating a very sharp drop in response. Many also have a problem with “doppler” distortion (remember your junior high physics; a car or train moving toward you or away from you causes the sound you hear to change in relation to distance as the sound waves are constricted or extended between your ear and the object in motion…), which is actually a product of phase and intermodualtion distortion caused by a speaker cone not moving uniformly. This is usually caused by the voice coil traveling beyond the magnetic gap in the motor assembly. An accoustic suspension design better controls the frequency roll-off, but can have issues with the build up of pressure behind the driver restricting its motion and causing distortion as the back wave of pressure builds up and directly acys on the woofer come surface from behind. Both ported and acoustic suspension designs also can suffer from sound bouncing off of inner cabinet surfaces and re-radiating back through the woofer cone, smearing the sound.  A properly tuned and damped transmission line has a smoother roll off, around 6dB/octave, that will extend bass response and allows the back wave of the driver to be optimally controlled while giving the best loading of the driver and reducing distortion. This technique has the ability to extend bass response without making it “lumpy” or creating a “one-note” characteristic. The Crescendo’s exceptional bass response and vanishingly low distortion are due to its complex transmission line loading technique, along with underhung drivers, to not only give tuneful, taut and deep bass response, but bass response that is in phase at the listening position to complement the proper time and phase relationships inherit in the rest of the design. The musical outcome is startling and can be immediately discerned with fast, coherent and powerful bass that lays a musical foundation for the music. Have a look at the frequency response sweep to the left and you’ll see that the Cescendo’s effective response is extremely linear and coherent across the audio passband with less than 3db of deviation from frequency to frequency, even at the acoutical crossover point between the transmission line port and the other drivers. Transmission line loading is not the easiest to implement, but it eliminates the “chuffing” and potential phase anomolies of ported designs and the power inneficiencies of acoustic suspension style cabinets. While our bass loading design is more complicated and more costly than most, it affords the truest response to the music, and that makes the extra work to implement it worthwhile.

Proper phase relationships are vitally important to speaker performance and its ability to reproduce a uniform, and musically correct output. Think of this example; If you held a few marbles in your hand that were uniform in weight and size, and dropped them to the floor with the intent of them all hitting at once to produce a single “crack”, they would actually all hit at different times and effectively “smear” the sounds your ear perceives since the sounds from the marbles would be striking the floor at different times and all react in different ways in the environment. They would hit the floor “out of phase” with each other. Now, let’s take those same marbles and drop them so that they all hit the floor uniformly and in perfect unison. If that is achieved, you will hear one coherent sound. They are now, “in phase”. This is a very simplistic example, but the end results are what’s important to understand; multiple incoherent sounds that smear what you want to acheive, or one uniform sound. Now, all speakers have some level of deviation in phase as amplitude and frequency change. This also affects the speakers load presented to the amplifier, but the ideal is to get the waveform to launch “in phase” with the signal at the input terminals and to keep from “smearing” that signal. We invite you to do some investigation of competitive products phase response and amplitude curves to see the surprising differences in some designs (some of which are in the upper echelon of high-end speakers in terms of their acceptance and their price!) In the Crescendo, that musical waveform is always produced in phase with the electrical input to the speaker with very little deviation and with a very stable impedance. The result is an output that is true to the input signal and simply outperforms others in terms of sheer musicality, listenability, coherence and accuracy.

The Crescendo employs a crossover network that is so highly refined in controlling the balance of the drivers that it yields a nominal efficiency of 90dB SPL @ 1 meter. The overall design keeps the impedance of the speaker at a nominal 6 ohms with no drastic shifts in phase and an easy load for almost any quality amplifier across the audio spectrum. So, while it will certainly respond to and fully complement powerful solid state amplifiers, it will also respond just as well with lower powered vacuum tube designs or high quality integrated amps. This is accomplished while maintaining unparalleled phase and time alignment, smooth frequency response and the lowest possible levels of distortion from the ultra-linear, under-hung driver design. The importance of both proper phase response and smooth impedance cannot be stressed enough; either one, improperly handled, can be the downfall of many competing loudspeaker designs. The Crescendo, however endeavors to ensure that both are high priorities. Proper phase relationships throughout the design ensure that music reaches you intact, as a whole, as it was intended. An impedance that stays smooth and with no wild swings across the frequency spectrum means your amplifier doesn’t have to struggle to reproduce the full spectrum of sound that you expect. Couple these with the ultra low distortion and linearity of the Crescendo’s drivers and you have a transducer that transcends all of the science, all of the engineering and all of the technology that we’ve put into it. The Crescendo will respond to what it’s driven with and consistently provide a musical experience like none other. Smooth response across the entire musical spectrum. Bass fundamentals that are deep, truthful, taut, and underpin the music as they should. Dynamics, truth of timbre, and imaging that are real and uncolored with an overall sound that is true to the source and non-fatiguing. 

In its new MkII version, we have also made improvements to the cabinet and its bracing to lower resonances and overall distortion. As with all Acoustic Zen products, you’ll continue to see an unparalleled level of fit and finish and some of the most beautiful cabinet works in the industry. People marvel at the quality of finishes on the Crescendo with its real wood veneers and deep, multi-coat clear finish. The Crescendo will look as good in your home as it sounds and comes in a number of finish choices to complement your décor. We ensure that the Crescendo is as beautiful to behold as it is to listen to!

Crescendo Finishes

All of this comes at a price that you may not believe. Most would expect a loudspeker with this level of refinement and technology to cost well into the five figure range, well above twenty, thirty, even forty thousand dollars. Instead, the new Crescendo MkII gives all of this performance for only $18,000. Many music lovers and audiophiles have already discovered the tremedous value of the Crescendo and replaced competing designs with price tags well beyond its own price. Most comment that they have searched for years for a loudspeaker with the musical performance of the Crescendo only to be disappointed time after time. The Crescendo has become a “final purchase” for many listeners. You may ask how we’re able to sell this level of quality and execution at this kind of a price, especially in light of the competition in the audio world. Let’s just say that we believe in selling a great product that can improve people’s enjoyment of music and movies at a price that is honest and in line with that product’s intrinsic value, not in line with hype, cachet or marketing spin.    

Does all of this technology and engineering deliver the goods? Considering our own testing and the comments of numerous reviewers and discerning audiophiles, the answer to that is a resounding, “Yes, and then some!!!”. The Crescendo’s design goal of faithfully reproducing the musical event has been completely realized. Musical integrity is kept intact with less distortion and greater fidelity across the audio passband than with most competing designs. The Crescendo creates a magnificent image with weight, authority, dynamics, warmth and coherence. And, unlike most of the current full range, high-end loudspeaker designs on the market which command enormous prices, the Crescendo is rationally priced. Crescendo owners are commenting that the Crescendo is the loudspeaker that has ended their quest for the best in musical reproduction, even after spending thousands more over the years on competing designs. The Crescendo is the obvious choice for the music lover looking for the ultimate in performance and value and could very well be your last loudspeaker. There are few high end loudspeker designs today that consistently receive the reviews the the Crescendo does after real life listening experiences. When people visit our show displays or our dealers and beging to listen, you’ll notice that they sink into their chair and listen to music instead of a speaker. Most Crescendo customers continually exclaim that they have found what they have been seeking for years. The Crescendo is designed to convey music’s power, timbre, nuance, dynamics, tone and ability to reach into the heart and soul of a listener like no other. We invite you to listen for yourself and experience the difference.
............ Robert Lee (Acoustic Zen Designer / CEO)

It’s important message for serious music-lovers
Robert Lee(Acoustic Zen Designer / CEO)

SUMMERY: We feel that there is no competitor, regardless of price, that can match the engineering achievement of our loudspeakers while being as natural sounding and independent of the amplifier driving them as possible. If you are passionate about music, if you want to listen to life like sound and the true spirit of music that will touch your heart at home, then I invite you to listen again to our speakers with your favorite recordings. Life’s too short to listen to speakers that are sub-par! If you change this or that in your system – front end components, amplification, speakers – and you’re still not satisfied, here is way to save your time and money…..get a pair of Adagio, Crescendo or Maestro loudspeakers from Acoustic Zen and you will smile and say “ That’s It !!”

EXTENDED COMMENTORY: I want to personally thank you for visiting us during one of the audio shows that we regularly display at and I enthusiastically invite you to visit us or one of our dealers to listen again to our magnificent, transmission line Adagio, Crescendo, or Maestro loudspeaker systems.  The Crescendo has received an enthusiastic Five-Star recommendation from Dick Olsher of The Absolute Sound, and over the past 10 years our loudspeaker systems have consistently garnered “Best Sound” and “Best Room” awards at every show we attend. There is a reason for that and I’d like to share some of the inside story around why that is and how Acoustic Zen’s speakers differ from others.

Most of us know that a speaker system is the most difficult component to properly design and manufacture in the audio reproduction chain. At the same time, it’s one of the easiest to get into the market with because it’s not always terribly expensive; drop a couple of high quality drivers into a box and voila’… you’re in the audio business. As long as you get sound out of them, seems that people will buy them, even if they sound lousy! That’s why there are so many speaker manufacturers. The truth is, very few exist that make products that are, as I said previously, properly designed and engineered and truly sound like music. A great loudspeaker has to reproduce 10 octaves of complex frequencies simultaneously and at the same time preserve the phase relationships of all these multiple fundamental tones and their harmonics. It also has to interface with the room to yield a proper, and musical, tonal balance while producing an extremely wide dynamic range of sound without audible distortion. In reality, these are difficult properties to achieve and one of the reasons I believe music lovers and audiophiles are continually changing speaker systems and components, searching for that elusive “something” that will finally satisfy their ears and their heart.

Let’s start with some basics. Why do different musical instruments have different sounds, even though they can play the same fundamental note? Different instruments use different methods for producing sound; like the strings of a guitar or a violin, reeds in a clarinet or saxophone, or just columns of air like a flute, organ, or the human voice. Some produce sound when struck like the head of a drum or the bars on a vibraphone or even the strings that are struck by hammers in a piano. Ultimately, they all vibrate and cause the air around them to vibrate in sympathy to create sound. Different instruments have different size, material, and shape and because of the different physical properties of different instruments, each note played by those different instruments do not vibrate at only that single, fundamental frequency. They produce vibrations at many different frequencies, often called harmonics, partials, or overtones. The relative pitch and loudness of these overtones gives the note a characteristic sound we call the timbre of instrument. 

Have a look at this You Tube video:

https://www.youtube.com/watch?v=VRAXK4QKJ1Q …you can see how fundamental and harmonic frequencies and various pitch structures are very complicated and complex in their waveforms for the same note when played by different instruments. So, when we listen to music imagine how complex the total soundwave must be! I discuss instruments and music because all of the frequency, pitch, phase, time, and amplitude of music relate to how we reproduce such complex soundwaves from a loudspeaker system, and why so many speaker system sound so different from each other.

Now, in an audio system, the speaker is a reactive load and it presents that reactive load to your amplifier. Being reactive means that it has resistance, capacitance and inductance, and the combination of these factors creates the speaker’s impedance. When you’re listening to music, the output from your amplifier is a recreation of the input signal and it drives that signal to your speaker’s voice coils with current. 

Because a loudspeaker's impedance is reactive, the current flowing to it from your amplifier will lag or lead the signal voltage by what is known as a phase angle. If you look at the impedance and phase curves of a couple of very expensive loudspeakers reviewed in Stereophile magazine you can see that the speaker’s impedance varies anywhere from 3 to 15 ohms as well as creating a phase swing of +45 degrees to -45 degrees. This is fairly realistic for most high end speaker systems, but some will even exceed this. How do those variances in impedance and phase angle ultimately affect the sound quality the speaker produces?

OK, let’s get a little technical… In an audio system, your amplifier “sees” the load presented to it by the loudspeaker. Ohm’s law, which is the basic formula for almost all electrical circuit engineering, tells us that voltage (V) is equal to current (I) multiplied by the resistance (R) in the circuit, so V= I x R. In simplest terms, the voltage at the amplifier output is affected by the resistance of the load to create the varying current required by a musical signal that drives the voice coil of the speaker. In reality it’s a little more complicated than that because, as stated previously, the load of a loudspeaker is reactive and not purely resistive as Ohm’s law assumes. So, that reactive load with its inductive and capacitive properties, the basic theory and from Power equation formula: Pavg = Vrms X Irms cos φ.(P is power output of the Amp system),we look at the “power factor” of the circuit, represented by cos φ. As you can see the voltage and current in the circuit are now affected by a reactive load where φ, is the phase angle the reactive load creates and the “power factor” is a function of the cosine (cos) of that phase angle. That reactive load now becomes a part of the amplifier’s “power factor” calculation. The reactive load will cause the signal to vary from its original state in relation to the impedance and phase angle characteristics of the speaker (inductive positive swings or capacitive negative swings). This causes some of the amplifier’s output to be wasted as excess current that performs no work and it gets dissipated as heat in the voice coils and causes the amplifier to work harder, and become less stable. Change one thing in the equation, like the phase angle and it affects everything else; you can’t fight physics! (note: cos 0 degree= 1, cos 45 degree= 0.707, cos 90 degree= 0)

So, you can see that the power output from your amplifier will vary with changing phase angles and impedances that are caused by a reactive load. The worst case is that the amplifier sees ether pure inductance (phase angle +90 degrees) or pure capacitance (phase angle – 90 degrees). Under those conditions, the voltage and current output from the amp are 90 degree out of phase; the cosine of 90 degrees is zero and that means no power is delivered to the speaker when it’s needed. Fortunately, this doesn’t normally happen because there is always a level of pure resistance in the impedance as well that counteracts some of that phase shift. However, because highly complex frequency soundwaves change very fast (maybe 100 Hz at this moment and changing to 2 kHz within a µsecond) and amplifier output varies with different frequencies, the shifting phase angle will alter the original fundamental and harmonic frequency’s amplitude and distort it to another overtone or timbre.

Another way we could explain the effect of phase angles in a loudspeaker is with the example of speaker polarity. As you probably know, if the left and right speakers are “out of phase” (the +/- terminals on one reversed form the other, 180 degrees reversed) it will cause the sound pressure that your speakers create to be out of phase and cancel each other, resulting in little or no sound. All of the sound stage will collapse and disappear and the overall amplitude will be lowered (if you face speakers directly at each other and out of phase, they will cancel even more, almost to the point where you cannot hear them at all). Try it yourself at home as this is an easy way you can experiment with these principals. Vocals will shift out of center stage and both pitch (the fundamental frequency) and overtone (the harmonics) of the original sound will be totally altered or canceled. This is what happens when the signal is out of phase 180 degrees. How about 90 or 30 degrees out of phase? What will happen to the sound? Well if the right channel has a sound wave at 1 kHz working at an inductive phase of +45 degrees and left channel has a sound wave at 2 kHz working at a capacitive phase of -45 degrees in the same time domain (see the first graph), the two frequencies are now out of phase 90 degrees with one source speaker creating compression and the other source speaker creating rarefaction. Consequently, there will be a very noticeable increase or drop in level (amplitude) compared with original sound wave, and the combined waveform will not reproduce the original musical overtones or timbre correctly.  In other words, incorrect phase leads to lateral image shifts but also alters the original timbre of the instrument in the signal. Obviously, the greater the impedance and phase angle shifts that are present at the speaker, the greater the effect on the amplifier’s output and power factor, and the overall system’s ability to correctly reproduce the musical waveform. The recorded music that we listen to via our speaker systems is highly complex; thousands of frequencies and amplitudes continuously changing in terms of micro seconds. Phase inaccuracies will cause the original frequency amplitude to shift and will also cause intermodulation distortion. Remember the graphics in the You Tube video? Look at the spectrum of different instrument’s fundamental and harmonics samples. 

When the phase angle swings up and down, it will color the original sound timbre or overtones. It’s similar to a synthesiser where you can actually adjust the different fundamental and harmonic frequency’s amplitude as well as their phase that emulate instrumental or vocal waveforms. This is the reason all the myriad brands of speakers systems sound so different, even though most of them have similar +/- 3db sound pressure level (SPL) specifications. However, most of them have such wildly varying impedances and phase curves that it damages the accuracy of their actual output. I challenge you to go check the past 30 years or so of speaker measurements in Stereophile (or any other publication that does performance testing) and look the impedance and phase measurements. You will find almost none that have flat and smooth traces. With some of them the electrical phase swings as much as +/- 45 degrees, but almost all have some level of variance, and that is one of the major factors that makes them all sound very different.

Human ears are remarkably sensitive to vibrations in the air, especially in the 200 Hz to 4 kHz range and this is where most fundamentals and primary harmonics created by most instruments and the human voice occur. When we listen to an instrument played live, we hear it in what we call absolute phase or absolute polarity; there is 0 degrees of phase shift in the sound you hear. Recorded sound by its very nature cannot perfectly reproduce that live sound, but good recording engineers do everything possible to recreate sound and music as faithfully as possible. They strive to capture the fundamental and harmonic content of music in a way that when played back through a quality system, will recreate that musical event as faithfully as possible. If you are looking for true, lifelike sound from your audio system, and want to get the event recreated as faithfully as possible, it is critically important that your speaker system has smooth and flat SPL but must also have impedance and phase curves that are smooth and flat or they will cause distortion of the musical waveform as we have demonstrated! 

I’m not going to talk about the importance of how to properly design a cross-over, or how to choose drivers, or cabinet design but wanted to emphasize how impedance and phase problems cause all kinds of distortions. To learn more about the technology we put into our loudspeakers, please see the attached white paper about our Crescendo… and take note of the impedance and phase measurements!  

It is key to listen to the spirit and essence of music reproduced from a speaker system with the most life like source possible and that is usually realized with recordings of unamplified, acoustic instruments.  

If you look at the Acoustic Zen Crescendo (or Adagio) speaker measurements for impedance and phase, you’ll see they are almost flat at 0 degrees. It is our belief that Acoustic Zen has solved the engineering problems associated with reproducing this wide spectrum of musical information in the most life-like manner via a loudspeaker.

Our speakers do not bloat the bass or suffer from the one-note bass associated with ported enclosure designs. The bass is fast and accurate and only speaks when the performers did. The  midrange drivers and tweeter are time and phase aligned with each other and the woofers to present a coherent point source that produces real-world, life-like images. Our loudspeaker systems are voiced to sound like a live acoustic concert and don’t transform it into an in-your-face and over processed musical event created by the wizardry in a recording studio – although, our speakers reproduce the latter very well also! On natural acoustic recordings, the timber and harmonics of vocals, pianos, stringed instruments, guitar, brass, woodwinds, percussion, and countless other instruments all sound like the real thing; not flashy, just natural. That’s because our speakers are so neutral and have such low distortion, not to mention wide dispersion, that they faithfully recreate the musical waveform better than competing brands that are sometimes two or three times the price. This greatly reduces listening fatigue and increases listener smiles! Plus, our speakers also present a benign load to power amplifiers so that both tube and solid-state amplifiers sound their best.

Years ago when I was manufacturing high-end audio amplifiers and cables, I owned some of the best loudspeakers the world had to offer at the time: and all of them sounded different and may great at part of spectrum but still missed the soul and spirit of music compared with any of the live concerts I attended. I know there have important mystery need to discover. This is why I decided to design and build my own loudspeakers that would actually perform as I expected. 

Of course it was very difficult to solve the myriad number of engineering problems inherent in creating a neutral and musical transducer. It took me more than 15-years of research and experimentation to achieve a speaker that I thought did justice to the ideal of recreating a live musical event. The Crescendo in particular is the result of those many years of development and it meets all of my design criteria: natural, musical sound with a very flat and smooth frequency response, exceptional phase accuracy, plus an almost purely resistive load to the amplifier (like those used on the measurement bench). The near perfect frequency response and life-like sound of the speaker would be lost if it presented a reactive load (non-zero phase angle) to the amplifier which would then add its own colorations to the reproduced sound.

We feel that there is no competitor, regardless of price, that can match the engineering achievement of our loudspeakers while being as natural sounding and independent of the amplifier driving them as possible. If you are passionate about music, if you want to listen to life like sound and the true spirit of music that will touch your heart at home, then I invite you to listen again to our speakers with your favorite recordings. Life’s too short to listen to speakers that are sub-par! If you change this or that in your system – front end components, amplification, speakers – and you’re still not satisfied, here is way to save your time and money…..get a pair of Adagio, Crescendo or Maestro loudspeakers from Acoustic Zen and you will smile and say “ That’s It !!”

………..Robert Lee(Acoustic Zen Designer / CEO)

Stereo Times w/ Crescendo at CES 2011

A larger pair of Acoustic Zen Crescendo loudspeakers were on demo again but this time in the Edge Electronics room.  They somewhat surprised me with their natural tone and excellent sense of ease.

This wasn't the first time I remarked on their excellence but this was the first time I heard the Crescendos with their grills attached. Nevertheless, I didn't detect any lack of transparency or a decrease in treble energy. if anything, the sound was actually sweeter and tad more relaxed.

The Edge NL series stereo amplifier (US$17,500), and G2 preamp (US$6k) made the Crescendos sing during my extended stay here. Hats off to this very musical and synergistic combination.

Acoustic Zen Crescendo is much better than anything I've heard from Magico - better than anything I've heard from Wilson too.
Sprezza Tura
Well I'm in the spend...... 
 
Magico has sounded nice - just nowhere near the price points IME. The Acoustic Zen Crescendo is much better than anything I've heard from Magico - better than anything I've heard from Wilson too. Fractions of the price. 
 
That's me calling it like I hear it. Problem is when reviewers say something negative people get on their case - look at Stereophile saying something luke warm (kinda negative) about Bryston - the S hit the fan. 
 
The problem is that people are "afraid" to look bad. People, including reviewers, often wish to placate the masses - and be viewed as part of the club.
Acoustic Zen Crescendo Speakers: The Best on the Scene Regardless of Price?
Jim Merod

Anyone who feels, as I have for nearly four decades, that speakers are a problem to be reckoned with, owes it to their own best interests to investigate the Crescendos. Anyone living with them will no doubt feel both relieved that an audio difficulty has been solved... and that so much improbable musical pleasure has entered their life at such little expense.

I can cite perhaps one other infinitely-nuanced speaker that stands near to the Crescendos, but it is many time the price of these over-performing musical units. At US$16,500/pr (NZ$23,995/pr incl sales tax), Acoustic Zen has brought forward works of art that grace any physical environment while setting the highest standard for musical brilliance and acoustic delicacy and power.

Several years ago I popped for a pair of Acoustic Zen's remarkable and drop-dead gorgeous Crescendo speakers. They had it all. The musical hunger that my heart and soul live with on a constant basis fully encountered aesthetic satisfaction, dynamic power, lyrical delicacy and (that most elusive of all parameters) soundstage accuracy and imagistic vividness, defined by holographic instrumental and vocal details. Many speakers previously had promised such joy. None had ever really delivered it.
 
There was no way that I'd allow myself to go on without a set of Crescendos. The deal was sealed after long audition with no disappointments. Those who endure my grouchy relationship to speakers of all sorts, and to price points, are aware that I've had a decades-long antipathy for speakers, with few exceptions. In truth, with only a single outlier, I've found virtually every microphone I've ever put into play to be a useful, sometimes glorious partner in my recording adventures. (Shure SM57s and 58s reconstructed for PA I do not require or care to indulge.)
 
When you consider that mics are inverted speakers, and vice versa, from a distance the anomaly of my distress with speakers appears unlikely or absurd. Yet there it is in full and graphic Technicolor sonic imprint. For me, speakers have always been the weakest structural link in the audio and musical chain.
 
Long ago, Richard Vandersteen's 2Ce speakers seemed like a wonderful gift to any truly engaged musically-inclined person. They were then and, oddly, still are. Even as the 2Ces do nothing extremely well specifically, the overall delivery of relaxed musical truth has always been both surprising and engaging... for a truly inexpensive price. Compared to many hyper-expensive speakers, the 2Ces are underwhelming, never "wrong" or quirky or an irritating musical partner. They wear well and offer real, if un-dramatic, musical satisfaction. I've never parted with them, and every so often put them in harness for nostalgic joy. Richard is an audio magician, and his recent (expensive) inventions are among the best ever. Also, my recent addition of the current iteration of Magnepan 1.7 speakers is no accident, but a result of their long trek toward a special acoustic footprint now beautifully accomplished. The Maggie's always promising planar design has come fully into its own, a potential "classic" arriving on the scene well sculpted, better late than never.
 
Acoustic Zen's Ascending Trajectory
 
Make no mistake here: when Robert Lee's improbably profound Crescendo speakers came into the marketplace several years ago, they were amazing in ways I've seldom if ever witnessed. And that was before he enhanced his "under hung" driver array. The Crescendos are now a unique audio instrument... something special to behold!
 
Let me admit my own thickness here. I was minding my business, perfectly content with the Crescendos' performance, when maestro Lee called to ask if I'd be interested in an upgrade to my reference speakers. "You're kidding me, right?" I responded, thinking that was a long shot, at best, maybe a bad idea given the timeless adage not to "fix" a very good thing.
 
Robert Lee wasn't teasing or jousting. Not long after, he arrived at Chez BluePort with a monster SUV to box up and cart off my favorite pair of never-fail music makers. A month went by and I asked myself if just maybe I was losing musical joy that could never be made up... if, by chance, I'd succumbed to the fickle goddess of "New and Different" without considering the fact that lost listening time is gone forever while so called "enhancements" sometimes turn out to be negligible or mere fantasies.
 
Life is fragile, judgment blind, time an implacable thief. One's proper motto against such odds: do no harm. What mischief had I wrought?
 
I Was In Error Differently
 
I was wrong to imagine that maestro Lee would mislead me into hoping for improvement in the form of a will o' the wisp.
 
Au contraire, mon ami. The good audio doctor made a great speaker way better. Much more mo' betta... stupendously enhanced. Virtually impossible to comprehend "better" in all aspects of sonic transparency and musical erotics. He replaced terrific drivers with ridiculously upgraded units that simply disappear. Sound that was once glorious became music so clearly defined (and refined) that it no longer seemed to be recorded. My own hi-rez recordings seemed immediately "there" with uncanny ambient reality.
 
Robert Lee's gentle surgeon's touch massaged a beautiful sounding pair of speakers into a sonic delivery system without equal in my main reference system... virtually unrivaled in long years of listening experiences. The Crescendos—always adorable and accurate as well as engaging and instructive—became jaw-dropping sonic delivery systems: thoroughly invisible but thoroughly palpable in their musical results. These speakers are defined by a sense of "you are there" acoustic intimacy, instrumental tonal accuracy, and musical openness.
 
Surveying the Spectrum
 
I can cite perhaps one other infinitely-nuanced speaker that stands near to the Crescendos, but it is many time the price of these over-performing musical units. At US$16,500/pr (excl sales tax), Acoustic Zen has brought forward works of art that grace any physical environment while setting the highest standard for musical brilliance and acoustic delicacy and power.
 
Doubtless I'll return to these lovely gifts to music lovers everywhere because the ongoing narrative of a great speaker entering new audio territory atop the Audio Himalayas is a story, and an experience, too alluring (and also well within reach of real world audio budgets) to overlook for long.
 
Anyone who feels, as I have for nearly four decades, that speakers are a problem to be reckoned with, owes it to their own best interests to investigate the Crescendos. Anyone living with them will no doubt feel both relieved that an audio difficulty has been solved... and that so much improbable musical pleasure has entered their life at such little expense.
 
I'll note, for the sake of truth, that the Crescendos are splendid with a variety of speaker cables. They're not a difficult load to drive and they are not fussy about cable mating. 
 
More reflections as they occur….
,,,,,,,, these speakers are for music lovers,
HiFier

Essentially, the Crescendo speakers are full-range Adagio speakers, which were already pretty full-range but were not enough for people with larger rooms or who listen to a lot of classical music and want the lower octaves to sound realistic. The Crescendo has a greater ease of presentation and a bigger, fuller sound. 

We are back from CES sorting large amps based on their micro-dynamic capability »Acoustic Zen Crescendo and Tri at Wherein we go into more detail about the sound at this year’s CES.
 
First, Robert Lee of Acoustic Zen knows how to set up a room at a show. He knows what kind of sound he is after, and if the amp he was supplied is not doing what he wants, he will put it on static display and use something else that gets the job done.
 
What this means is that 1) you can go to their room at a show and be pretty certain it is not going to suck. In fact, it will likely be quite good sounding [we’ll go into what good sounding means in this context below], and 2) that the amps he is using are amps YOU can use with these Acoustic Zen speakers and be pretty sure that it is going to also sound good.
 
Yes, this is indeed extremely rare. By far most rooms (99% or so), even ones we give best of shows to, either A) sound good because they got lucky and the unfamiliar amp from a manufacturer who was the first to agree to share costs of the room JUST HAPPENED to sound good with the speaker manufacturer who was the first to agree to pay some of the room costs or B), the quality of one of the components, or the speakers, is so good that even with mismatched components the room still sounds pretty good.
 
Acoustic Zen has paired with Red Dragon, Edge, Response Audio and Tri. 
 
Essentially, the Crescendo speakers are full-range Adagio speakers, which were already pretty full-range but were not enough for people with larger rooms or who listen to a lot of classical music and want the lower octaves to sound realistic. The Crescendo has a greater ease of presentation and a bigger, fuller sound. 
 
Which I think is the point of these speakers. 
 
First, most speakers in this price range suck. They are a joke. Few attempt to do full range and those that do usually suck more.
 
Let’s talk about the ones that do not suck for a minute.
 
We have the Marten Miles III and Kharma 3.1C. More detail, more transparency, more audiophile, but no where near the authority or frequency range.
 
The Soundlab A1 has the frequency range, but not the authority unless you really out a mofo amp on it, but if you want a electrostatic then you are probably not reading this post anyway.
 
You got the Wilson Sophia [not the range or sense of ease], Avalon… not sure which one [not the authority or range], Audio Note [if you have corners available. If you do then this might be a possibility, with careful attention to setup]. Let’s see… what else? 
 
Most people who come here to demo these speakers, to tell you the truth, have just come from auditioning the B&W, Definition, and JM Lab/Focal. They have just been fed tipped up midrange hell and musical slurry. They are rarely audiophiles and we have so little time to demonstrate to them that they are on the road to ‘audio hell’ [when they see $350K speakers, they think we have already arrived at audio nutsville  ]. The Acoustic Zen are audiophile-grade speakers, whereas the others are not [sorry]. Which takes us to the next section.
 
These speakers have what I think of as 2 distinct sounds - depending on the amp driving them. With a Red Dragon amp, or little Kharma amp, these are very dynamic, fairly quick sounding speakers. With Edge amps and tube amps, these are more…tube-like, a little more harmonic and continuous. With BAT amps you can achieve the middle ground - more or less.
 
We’ve found people greatly prefer either one or the other with these speakers (whereas we do not, we like both flavors of sound).
 
I think these speakers are for music lovers, not quite so much into the sophisticated sound gymnastics as some audiophiles are [guilty as charged, love those crazy subtle details and intricacies!] , and want a audiophile-grade full-range speaker for an audiophile-grade 2-way speaker price.
CES mini review - At Your Peril: A Glimpse.......I'll be back!
Jim Merod

One thing leading to others, I leaned hard. Word was out that CES would sport the full debut of Acoustic Zen's new top-of-the-line Crescendo speakers—a revamped working set, not the mock up not-quite-ready-for-prime-time pair seen at the recent Rocky Mountain Audio Show. I wanted a preview audition.

I can be pushy. I don't want to be. My mom raised me to be a nice kid, but sometimes (let's face it) you have to lean on a door to get it open.
 
A week ago I called the Acoustic Zen dudes in fire-ravaged Rancho Bernardo, not far from my hilltop enclave in northern San Diego county. I asked if they'd dodged the fury of firestorms that swept across this region. They had. Barely. Close is good in both horseshoes and fire-avoidance.
 
One thing leading to others, I leaned hard. Word was out that CES would sport the full debut of Acoustic Zen's new top-of-the-line Crescendo speakers—a revamped working set, not the mock up not-quite-ready-for-prime-time pair seen at the recent Rocky Mountain Audio Show. I wanted a preview audition.
 
Granted. Within two hours I sat my fanny in a comfortable seat dead middle of the impressive Crescendo multi-driver "under hung" designed speakers ...I was immediately off and roaring with 'oohs' and 'wows' to spare. This was a rip-roaring "whup it up" experience, I'll assure you.
 
The Crescendos are big, an elaboration of Acoustic Zen's award-winning Adagio speakers—a three-way design featuring two eight inch "under hung" woofers with a long magnetic gap and a short voice coil. Their midrange is comprised of two five inch "under hung" drivers. The system is completed by a horn-loaded ribbon tweeter that opens an enormous sense of ambient space.
 
At 125 pounds, each speaker is truly a behemoth. These speakers are rated at a modest 86dB (20Hz to 30kHz), but Robert Lee is furiously working, in preparation for Las Vegas in early January, to improve their sensitivity. The 90-plus minutes I spent with them, listening to my own recordings, convinced me that the Crescendos do not need much tweaking or refining at all. They are more than "impressive." I was deeply surprised by their sonic accuracy and micro-resolution.
 
I was also physically slammed by their bass response, quick and full and tonally complex. Most of all, the stage that the Crescendos establishes is as true-to-life as any I've ever encountered ...in fact, I suspect that their sense of three-dimensionality and of ambient depth, height, and width outperforms any other speaker (at any cost) I've heard.
 
SP Technology's Continuum speaker system (with its vaunted "wave guide") is a true audio champion, capable of throwing a huge and utterly convincing stage ...placing an auditor in a spooky "you are there" listening position. But the Crescendos appear to match or top that in one very specific sense that's utterly beguiling. They surround you front to back, side to side, with near "surround sound" vividness generated from a single stereo pair. The feeling of being-at-the-location where music was recorded is awesome and delightful as well as bloody hard to comprehend. Part of my initial listening was devoted to an attempt to deconstruct—to analyze and make literal acoustic sense—of these speakers' other worldly disappearance.
 
You Might Be "There" (Stay Tuned)
 
If Robert Lee improves the Crescendos, as he seems hell bent on doing, I'd suggest that an already hard to believe listening experience may become ....orgasmic? Stupidly real and therefore mind-numbingly silly? I do not know how to anticipate these speakers with further resolution, delicacy, relaxation and musical verisimilitude. I want to hear them, if that's the case. Yep, I sure do! But, I'll terminate my brief preview of this $12,000 speaker system—my underlining one critical term in my somewhat staggered witness. RELAXATION. 
 
Audio relaxation. Musical relaxation. 
 
The Crecendos may offer the most relaxed presentation of fully-dynamic musical acoustics I've yet dwelt with (alas, at present, too brief, in truth). Thus, I've now begun a small personal mission to check this audio phenomenon further. I love what I heard. I was nearly overwhelmed by the effortless "reality" of the Crescendo's musical presentation ...music I recorded and had never previously heard recreated (re-presented) so accurately and with utterly convincing analog spatial relaxation.
 
I'll begin my increased scrutiny in Las Vegas at CES. I'll haunt Acoustic Zen's fire-salvaged showroom and warehouse once again.
 
I'll not let this haunting and haunted experience of "returning to the scene" of my own boisterous recording mayhem without added surveillance, more precise inspection—the full thrust of pushy critical interrogations.
 
I'll be back!
Should the Acoustic Zen Crescendo be your last speaker?
Acoustic Zen paper on their unique Crescendo

The world of high-end loudspeakers can be a maddening and sometimes rocky place to traverse. Many audiophiles continuously search for a speaker that will satisfy their needs only to continuously discover that over time, a speaker may become fatiguing, uninteresting, or simply intolerable to listen to. Unfortunately, this can also come with a heavy price tag, even up to the six figure range. So, what if you could find a loudspeaker that actually fulfilled the high-end promise of smooth, full range frequency response, time and phase alignment that creates superb images in space, with vanishingly low distortion and gorgeous finishes all at a price that is within the reach of most music lovers? Your speaker is here today!

The Acoustic Zen Crescendo is being received at shows around the country, on dealer floors, and in our customers’ homes by audiophiles, reviewers and pundits with incredible acclaim. But, how do we get such exceptional sound quality in the first place? The answer is in a design that utilizes solid technologies and techniques that serve the musical waveform first and foremost. Let’s face it, there are lots of high quality loudspeaker designs in the high-end, so what exactly makes the Crescendo different from the rest of that packed landscape? 
 
First and foremost, the Crescendo was designed for music and with real, live music as the reference. The reality is that most audiophiles and music lovers spend time with their systems listening to music, not thunderstorms or train whistles. Musical signals are highly complex and reproducing them effectively is not necessarily as easy as it may seem. But, with properly utilized technology, design principals and exhaustive testing it is possible to create a transducer that is faithful to the musical signal. The Crescendo accomplishes full range response along with low distortion, dynamic impact, coherence, efficiency, and truthful imaging.
 
The drivers utilized in a quality speaker design are its heart and most important component. To ensure a solid foundation we have consistently utilized “under-hung” driver technology in our designs. The principal of the under-hung driver is that the voice-coil is narrower than most conventional drivers’ voice-coil and essentially never leaves the magnetic gap of the motor assembly. Basically, the voice-coil is shorter than the magnet’s gap or “under-hung”. The vast majority of speakers utilize the opposite or “over-hung” drivers where the voice coil easily travels beyond the magnetic gap of the magnet assembly because it is longer than the magnet’s actual gap. Think about when you were back in junior-high science; remember playing with magnets? Specifically, the demonstration where you took a bar magnet and placed it under a sheet of white paper and sprinkled some iron filings on top of the paper. When the filings were in close proximity to the magnet, they were more orderly and you could make out the magnetic lines of flux and the further away from the magnet the iron filings were the more disorderly they became. The principal of an under-hung driver is much the same. Since the driver’s coil is always inside of the magnetic gap of the speaker’s motor assembly, it’s under the influence of the magnet across its entire range and it’s response has less distortion, kind of like the bar magnet experiment. With over-hung drivers, the coil travels beyond the magnetic gap and causes distortion in its movements, much like the iron filings that are too far away from the influence of a magnet. The advantage to the under-hung driver is vastly lower distortion since the coil is always under the influence of the magnetic gap and how it is influenced by the incoming signal voltage. That being the case, why don’t more manufacturers utilize under-hung driver technology to achieve lower distortion designs? Well, there are a couple of reasons; one is expense and the other is that over-hung drivers are easier to work with. Essentially, with a conventional, over-hung driver the tolerances and materials do not have to be as rigid and any anomalies in the response and distortion properties can usually be ameliorated with crossover tweaks and cabinet construction techniques. With under-hung drivers, the expense is greater and the need for very careful matching of components and materials is critical, but the outcome more than compensates for the diligence required in their use. That’s why the Crescendo’s mid-bass and bass drivers are all under-hung designs to gain the lowest possible levels of distortion and pass the benefits to the listener. 
 
As you look at the front of the Crescendo, you will see that the upper drivers are in a D’Appolito MTM configuration. This allows the best possible recreation of the original waveform and eliminates the “lobing” effect common with other configurations. The advantage to this is that the audio signal will reach the listener in proper phase and time relationships with no smearing due to the signal interactions inherent in conventional designs.
             
Two five inch mid/bass drivers that employ a unique magnesium alloy impregnated paper cone material flank a horn loaded ribbon tweeter specifically designed and manufactured for the Crescendo. This MTM array asures smooth frequency response with proper phase and time relationships intact and the ribbon tweeter is implemented to provide extended, open, and non-fatiguing response. An aluminum ribbon covers 95% of the vibrating area of the tweeter membrane. This unique feature provides a purely resistive impedance which means a friendly load for the amplifier and simplifies crossover design.  The vibrating element is almost completely weightless compared to traditional dome type tweeters. This affords immediate and precise high-end response to transients in the musical signal and reveals the dynamics of instruments with high frequency specrtral content like no other. It has an essentially linear phase response which provides time coherent reproduction resulting in accurate frequency  response, rhythmic drive and outstanding imaging capability. Our tweeter is quick, without distortion  and without ringing. Many modern “audiophile” speakers seem to have tilted up or bright treble response which lends a bit of excitement to the sound, but long term causes listener fatigue and dissatisfaction with the overall tonal balance of the speaker. The Crescendo’s mid to high end response is natural, non-fatiguing and remains faithful to the source. 
 
To convey deep bass with resolution and authority, dual eight inch, ceramic coated, underhung drivers are transmission line loaded to extend response to a true 20 Hz. A properly tuned and damped transmission line has the ability to extend bass response without making it “lumpy” or creating a “one-note” characteristic. The Crescendo’s exceptional bass response is due to its unique ability to utilize this loading technique to not only give tuneful, taut and deep bass response, but bass response that is in phase at the listening position to complement the proper time and phase relationships inherit in the rest of the design. The musical outcome is startling and can be immediately discerned with fast, coherent and powerful bass that lays a musical foundation for the music. Have a look at the frequency response sweep to the left and you’ll see that the Cescendo’s effective response is extremely linear and coherent across the audio passband with less than 3db of deviation from frequency to frequency, even at the acoutical crossover point between the transmission line port and the other drivers. Transmission line loading is not the easiest to implement, but it eliminates the “chuffing” and potential phase anomolies of ported designs and the power inneficiencies of acoustic suspension style cabinets. While our bass loading design is more complicated and more costly than most, it affords the truest response to the music, and that makes the extra work to implement it worthwhile.
 
Proper phase relationships are vitally important to speaker performance and its ability to reproduce a uniform, and musically correct output. Think of this example; If you held a few marbles in your hand that were uniform in weight and size, and dropped them to the floor with the intent of them all hitting at once to produce a single “crack”, they would actually all hit at different times and effectively “smear” the sounds your ear perceives since the sounds from the marbles would be striking the floor at different times and all react in different ways in the environment. They would hit the floor “out of phase” with each other. Now, let’s take those same marbles and drop them so that they all hit the floor uniformly and in perfect unison. If that is achieved, you will hear one coherent sound. They are now, “in phase”. This is a very simplistic example, but the end results are what’s important to understand; multiple incoherent sounds that smear what you want to acheive, or one uniform sound. Now, all speakers have some level of deviation in phase as amplitude and frequency change. This also affects the speakers load presented to the amplifier, but the ideal is to get the waveform to launch “in phase” with the signal at the input terminals and to keep from “smearing” that signal. We invite you to do some investigation of competitive products phase response and amplitude curves to see the surprising differences in some designs (some of which are in the upper echelon of high-end speakers in terms of their acceptance and their price!) In the Crescendo, that musical waveform is always produced in phase with the electrical input to the speaker with very little deviation and with a very stable impedance. The result is an output that is true to the input signal and simply outperforms others in terms of sheer musicality, listenability, coherence and accuracy.
 
The Crescendo employs a crossover network that is so highly refined in controlling the balance of the drivers that it yields a nominal efficiency of 90dB SPL @ 1 meter. The overall design keeps the impedance of the speaker a nominal 6 ohms with no drastic shifts in phase and an easy load for almost any quality amplifier across the audio spectrum. So, while it will certainly respond to and fully complement powerful solid state amplifiers, it will also respond just as well with lower powered vacuum tube designs or high quality integrated amps. This is accomplished while maintaining unparalleled phase and time alignment, smooth frequency response and the lowest possible levels of distortion from the ultra-linear, under-hung driver design. The importance of both proper phase response and smooth impedance cannot be stressed enough; either one, improperly handled, can be the downfall of many competing loudspeaker designs. The Crescendo, however endeavors to ensure that both are high priorities. Proper phase relationships throughout the design ensure that music reaches you intact, as a whole, as it was intended. An impedance that stays smooth and with no wild swings across the frequency spectrum means your amplifier doesn’t have to struggle to reproduce the full spectrum of sound that you expect. Couple these with the ultra low distortion and linearity of the Crescendo’s drivers and you have a transducer that transcends all of the science, all of the engineering and all of the technology that we’ve put into it. The Crescendo will respond to what it’s driven with and consistently provide a musical experience like none other. Smooth response across the entire musical spectrum. Bass fundamentals that are deep, truthful, taut, and underpin the music as they should. Dynamics, truth of timbre, and imaging that are real and uncolored with an overall sound that is true to the source and non-fatiguing. 
All of this comes at a price that you may not believe. Most would expect a loudspeker with this level of refinement and technology to cost well into the five figure range, well above twenty, thirty, even forty thousand dollars. Instead, the Crescendo gives all of this performance for only $16,000. Many music lovers and audiophiles have already discovered the tremedous value of the Crescendo and replaced competing designs with price tags well beyond its own price. Most comment that they have searched for years for a loudspeaker with the musical performance of the Crescendo only to be disappointed time after time. The Crescendo has become a “final purchase” for many listeners. You may ask how we’re able to sell this level of quality and execution at this kind of a price, especially in light of the competition in the audio world. Let’s just say that we believe in selling a great product that can improve people’s enjoyment of music and movies at a price that is honest and in line with that product’s intrinsic value, not in line with hype, cachet or marketing spin.    
 
Now, if all the Crescendo did was give you highly refined engineering and great sound, its cost would still be amazing. But on top of all this, you also get an unparalleled level of fit and finish and some of the most beautiful cabinet works in the industry. People marvel at the quality of finishes on the Crescendo with its real wood veneers and deep, multi-coat clear finish. The Crescendo will look as good in your home as it sounds and comes in a number of finish choices to complement your décor. We ensure that the Crescendo is as beautiful to behold as it is to listen to! 
  
Does all of this technology and engineering deliver the goods? Considering our own testing and the comments of numerous reviewers and discerning audiophiles, the answer to that is a resounding, “Yes, and then some!!!”. The Crescendo’s design goal of faithfully reproducing the musical event has been completely realized. Musical integrity is kept intact with less distortion and greater fidelity across the audio passband than with most competing designs. The Crescendo creates a magnificent image with weight, authority, dynamics, warmth and coherence. And, unlike most of the current full range, high-end loudspeaker designs on the market which command enormous prices, the Crescendo is priced at an incredibly rational level. There are lots of Crescendo owners out there that have found that to be true and are commenting that the Crescendo is the loudspeaker that has ended their quest for the best in musical reprooduction, even after spending thousands more over the years on competing designs. The Crescendo is the obvious choice for the music lover looking for the ultimate in performance and value and could very well be your last loudspeaker. Don’t believe us? Here’s a few comments from around the audio press….
 
“…offering more than a small taste of ne plus ultra performance: finely drawn treble, meaty midrange, taut, deep bass, and surprising large-scale dynamics.” 
.....The Audio Beat,  T.H.E. Newport 2012 Report
 
“…The sound was exceedingly warm and inviting… when music was played at optimal levels, the sound was lovely.” 
.....Jason Victor Serinus, Stereophile, T.H.E. Show Newport 2012
 
“… one of the show’s best sounds despite the price disparity between the Crescendo and the other best of show contenders.” 
.....Robert Harley, The Absolute Sound, T.H.E. Show Newport 2012“…
 
The sound was simply spellbinding. I can't recall hearing imaging this good on any system using conventional speakers for less than US$100,000” 
.....Sound Stage, CES 2012 Report
 
“…This is the gear we take home to our long-suffering families and loved ones and they finally say, ‘Wow. I get it now.’ ” 
.....Confessions of a Part Time Audiophile, Newport 2012
 
“The resulting sound was breathtakingly natural. It flowed with ease and grace, pouring out the best sound I have heard at any audio show—and I have been to plenty.” 
.....John Broskie, Tube CAD Journal, RMAF 2012 Report
 
“The Crescendois eminently musical and supremely well-integrated from top to bottom and is currently my favorite box speaker under $30k. Make no mistake about it: The Crescendo is a fantasticvalue at its asking price. An enthusiastic five-star recommendation! 
.....Dick Olsher, The Absolute Sound, January, 2013
The Return of the Transmission Line - the Crescendo is a fantastic value at its asking price...an enthusiastic five-star recommendation!
Dick Olsher

Acoustic Zen’s Robert Lee has crafted a magnificent transmission-line speaker, truly a perfectionist labor of love. The Crescendo is eminently musical and supremely well-integrated from top to bottom. It certainly pushed of all my emotional buttons and is currently my favorite box speaker under US$30k. Make no mistake about it:

When A. R. Bailey unveiled his novel “non-resonant loudspeaker enclosure” in 1965, commonly referred to today as a classic transmission line (TL), he took direct aim at the popular bass-reflex speaker design. Bailey’s measurements and listening tests highlighted the poor transient response of a bass-reflex enclosure. Such an enclosure is clearly resonant, even if tuned for a maximally flat response, due to its reliance on a Helmholtz resonator to invert the phase of the woofer’s back wave. The problem, as Bailey saw it, was that when an impulse stopped the bass-reflex port would continue to radiate for many milliseconds. His solution for tight and natural bass response was an acoustic line loosely packed with long- fiber wool. The TL became a hot topic for DIY experimentation throughout the 70s and 80s and was commercially available from several companies, most notably IMF and Fried in the U.S. For commercial reasons, the TL never displaced the bass- reflex enclosure since, for a given bass cutoff frequency, the TL consumes a much larger volume and is more costly to construct. And while designing a bass-reflex enclosure for a given woofer is pretty much a cookbook process in this day and age of Thiele- Small parameters, up until very recently there wasn’t sufficiently reliable TL design software available. In fact, Bailey in his seminal articles only described the overall design principles and failed to specify a process for matching a TL to a given woofer. Today, a TL is a rare bird in a forest of bass-reflex designs. It has been ages since a commercial TL visited my listening room; as I recall, it was one of Bud Fried’s designs circa the mid-80s. And so I was really looking forward to the transmission-line-loaded $16,000 Crescendo, especially in view of its stellar performance at past audio shows since its introduction at CES 2006.
 
There are two essential things you need to know about a transmission-line speaker. First, it is a quarter-wave resonator. Sound energy, which is reflected from the open end of the pipe, sets up multiple standing waves. As with any pipe open at only one end, its fundamental resonant frequency has a wavelength equal to four times its physical length, which is to say that the longest sine wave that fits into the pipe is four times as long as the pipe. That means that the lowest frequency such a pipe can be energized by corresponds to c/4L where c is the speed of sound and L is the length of the pipe. An example from the musical instrument world would be the clarinet. Its physical length is about two feet, but the clarinet can produce a note whose fundamental wavelength is about eight feet long, which corresponds to a frequency of 140Hz or C# below middle C. Of course, there are higher-order pipe resonances at odd multiples of the fundamental, which give the clarinet its distinctive timbre. In a transmission-line speaker, these are largely damped out by stuffing the line with absorbent material
 
The second thing to recognize is that the transmission line acts as a delay line with respect to the backwave of the woofer. Since the backwave is 180 degrees out of phase relative to the front wave, the line needs to be sufficiently long to minimize destructive cancellation down to a specified bass frequency. Only at frequencies where the effective line length is equal to or greater than a half wavelength does the line output reinforce the woofer’s front radiation. Short lines simply can’t provide any deep bass augmentation. The Crescendo’s physical line length is about 9 feet, which is effectively stretched by the frictional effects of the stuffing material, a mix of poly-fil micro-beads and cotton fibers, to an apparent length of 13 feet. This means that while the line’s output is extended to 20Hz, it only adds constructively to the woofer’s front radiation down to a frequency of about 40Hz.
 
Most classic TL designs take advantage of the fact that the fundamental pipe resonance creates a pressure maximum at the closed end of the pipe, and of course, a pressure minimum (nearly atmospheric) at the open end. The line length is then chosen to match the line’s fundamental resonant frequency to the woofer’s free-air resonance in order to dampen the woofer’s excursion at resonance. The Crescendo woofer’s free-air resonant frequency happens to be 25Hz, and is consequently well damped by the fundamental TL resonance which is around 20Hz.
 
The Crescendo is a three-way, five-driver design. The TL is energized by a pair of 8-inch woofers which feature coated paper cones and underhung voice coils. Although far less common than the overhung voice coil, its advantages are reduced moving mass, lower inductance, and a more linear motor strength over its excursion range, which translates into lower distortion. On the downside, an underhung design is costlier to manufacture, but that is hardly an important consideration in the context of high-end audio. The two 5-inch midrange drivers and tweeter are arranged vertically in a D’Appolito configuration in order to maximize response uniformity in the vertical plane. The tweeter is a quasi-ribbon design with an aluminum coating over Kapton and incorporates neodymium magnets and horn loading. The woofers are crossed over at about 250Hz using a second-order low-pass network. The mids also use coated paper cones and underhung voice coils. The tweeter is rolled in around 2.1kHz and is well protected against over-excursion by a third-order (18dB/octave) high-pass network. All internal wiring is said to be 10-gauge single-crystal copper.
 
My measurements highlighted what in my book could only be described as an extremely successful design. The in-room frequency response was exceptionally uniform on axis, not only in the nearfield, but also at the listening seat. Bass response was flat nearfield (at about 4 feet) to about 50Hz with a strong contribution from the transmission line port (but several dB less in level) in the 40 to 50Hz range. With room gain, response flatness was extended to about 40Hz at the listening seat. The minimum impedance was about 4 ohms, but the impedance magnitude and phase were quite uniform over the speaker’s entire bandwidth, the impedance magnitude only varying within a factor of two. That’s a far cry from the impedance variations of a typical bass-reflex loudspeaker, which can exceed an order of magnitude. And that makes the Crescendo very accommodating of high-source-impedance amplifiers, as it intrinsically minimizes amplifier-speaker load interactions. Zero-feedback, single-ended triode (SET) amplifiers can be safely used without impacting tonal neutrality.
 
While I expected the pairing of the Crescendo with the Triode Corporation M845SE SET monoblocks to be compatible, I was genuinely surprised by the extent to which it turned out to be a match made in audio heaven. My first listen during CES 2012 (with all Triode Corporation tube electronics) impressed me mightily, so I was pleased that Twin Audio-Video’s Santy Oropel, the Triode Corporation distributor, joined Acoustic Zen’s Robert Lee in delivering and setting up that exact system in my listening room. Just when I thought that the SET genre had been exhausted in terms of plausible design variations, the M845SE proved me wrong. The output stage consists of a pair of parallel-connected 845 (or 211) directly heated triodes, driven by another 845 via an interstage transformer. I tried both output stage configurations and clearly preferred the sound of the 845 as being more vivid harmonically, better focused, and more dynamic. I experimented with speaker toe-in angle and preferred to intersect the tweeter axes in front of the listening seat in order to obtain the widest sweet spot and soundstage lateral extension.
 
While I usually leave any discussion of bass performance toward the end of a review, preferring to start with the midrange, there’s a compelling reason to reverse that order in the case of the Crescendo. To confess, it became painfully obvious that I had been living in a state of perpetual sin listening to bass reproduction all of these years through bass-reflex loudspeakers. The Crescendo made that crystal clear as it recalibrated my expectations in the bass range. The attack and decay of an impulsive input signal such as a kettledrum strike is stretched in time by a phase-inverter speaker because a resonator takes time to build up and then decay the signal. It’s a well-known psychoacoustical fact, and a critical performance factor, that our ears interpret transient signals primarily in the time domain. A classic experiment involves reversing the signal’s attack and decay by playing a transient backwards in time. The result is total auditory confusion. As a consequence, it’s fair to say that a bass-reflex speaker reproduces an impulsive signal in slow motion. It may not matter as much with organ music, which lacks crisp attack and decay, but as the Crescendo made clear, even when driven by the M845SE, tympanic strikes on a properly loaded transmission line are peerless in terms of control and definition. What the Crescendo lacked in ultimate bass extension it made up for with superlative time-domain performance.
 
The transition from the bass to the midrange was seamless and without any audible discontinuity. The Crescendo maintained realistic tonal weight while doing justice to the power range of an orchestra. In these respects it performed with greater conviction than the similarly priced MartinLogan Summit X electrostatic hybrid, which tends to sound leaner through the upper bass. Of course, the Crescendo lacked the midrange transparency and textural delicacy of the Summit X, but it wasn’t that far behind. It was also adept at re-creating a persuasive spatial impression with excellent depth, width, and nicely focused image outlines. However, my personal preference is for a dipole midrange, which I find, at least in my listening room, to provide an enhanced spatial impression and a more immersive you-are-there experience.
 
In speaker land, what separates the men from the boys is typically how well a tweeter is integrated with a mid or woofer. It’s often not so much about the choice of tweeter as it is about selection of an optimal crossover frequency and a sufficiently steep high-pass network to adequately protect a tweeter from over-excursion. For me the sonic kiss of death is a tweeter whose distortion spectrum rises with signal level. In my many years of audio reviewing, I’ve endured so many ruthless-sounding tweeters that I’ve developed an extreme sensitivity, an allergic reaction if you will, to any upper- midrange and treble harshness, grit, or gratuitous brightness. I’m happy to report that the Crescendo’s ribbon tweeter is a winner, capable of reproducing sweet and refined harmonic textures with convincing transient finesse. Its level of purity gives full scope to violin overtones and female voice even when driven to loud playback levels. The treble is so well integrated with the corpus of the midrange that I found it hard to believe that it was actually crossed over in the upper midrange around 2kHz.
 
The overall tonal balance was quite neutral sounding, and did not display an inherent bias. Of course, the balance could easily be tilted toward midrange warmth by a tube front end or overly tubey power amp. But to its credit, this is a speaker that allows the end user to make those sorts of editorial decisions. The Crescendo was just as comfortable with solid-state amplification, though it was at its microdynamic best, able to plumb the emotional depth of a recording, when partnered by the M845SE monoblocks. However, the macrodynamic range was best served by a higher-power amplifier such as the Bob Carver Cherry 180. This was a partnership that made it possible for the Crescendo to live up to its name. Orchestral crescendi were scaled effortlessly without compression or distortion. In fact, the Crescendo brought out the best in the Cherry 180. The resultant soundstage was transparent, dimensional, and bubbling with kinetic energy—the essential ingredients for a goosebump- producing experience. It’s fair to say that the Carver amplifier with its pentode-connected output stage and a 1.7-ohm source impedance benefitted from the Crescendo’s uniform impedance magnitude and associated linear phase. Pentode amps in general welcome a resistive load, but unfortunately most real-world loads are inductive and/or capacitive in nature. As a consequence, pentode amps are difficult to match successfully. The Crescendo comes about as close to being an ideal resistive load as one can expect from a box speaker. It’s the sort of dream load every pentode amp would appreciate.
 
Acoustic Zen’s Robert Lee has crafted a magnificent transmission-line speaker, truly a perfectionist labor of love. The Crescendo is eminently musical and supremely well-integrated from top to bottom. It certainly pushed of all my emotional buttons and is currently my favorite box speaker under $30k. Make no mistake about it: The Crescendo is a fantastic value at its asking price. An enthusiastic five-star recommendation!
why did it take so long?........the Acoustic Zen Crescendos are alluringly seductive
Jim Merod

 if the sky's limitless horizon is the only permanent background for thought and knowledge, then speakers as refined and bold as the Crescendos are demonic companions for knowledge and thought… with a feeling enhanced by the exotic perfection of the sky's endless reach.  (Excuse me?)

Why did it take so long?
 
I'm a fussy audio listener. I'm incorrigible, a pain in the derriere when the topic—and, more important, the moment—is all about sound quality. Or its partial appearance... you know what I mean here.
 
How many times have you sat in your "sweet spot," right smack in the middle of Audio Nirvana, and whatever "nirvana" means to you right then… perhaps like that time long ago when you were peeking through Jane Smiley's bedroom curtain from your twelve year old perch on her plum tree. Oh, sure, the adorable Jane was right there before your libidinous youthful gaze. She was, alas, amazingly disrobing and you were actually there to watch the whole hilarious festivity: her sprightly young breasts, your hungry eyes; her blithe insouciance, your anxious hopefulness.
 
All that, but no cigar, bozo! You put yourself in that lofty sweet zone only to discover that, well Jane inexplicably kept her back to her partly open window while her curtains wafted far too flappingly wide. Your tenuous grip on your fragile perch was flat out uncomfortable. So the whole idea, which made sense when you put it together, collapsed once our slippery seat gave you nothing of hers.
 
That's pretty much the way it is across the vaunted glory years of "The Age of High-End Hi-Rez Audio Perfection." Gumba. 
 
Here we are, dig? Where do we go from here?
 
First, a question. Why else do so many "audiophiles" swap out components and cables endlessly in search of "more"... more audio glory; more musical enchantment; more erotic, amorous lyrical titillations? 
 
Answer. Because their audio "sweet spot", ain't so sweet. Listen up, Flap-jack. You know all this as much as I do and, still, you suffer onward seeking some micro-boosted sonic advantage that will take the sting out of your aching audio-hungry soul. You reposition your speakers. More toe in. No, less toe in! Or you relocate everything and then add baffles because, surely, these final adjustments are going to do it once and for all.
 
But no "final" placement or set up arrives. Your search for audio nirvana continues unabated. Some of you, frankly, get pissed and junk the whole damn hobby. I know that for a fact because I've had two innocent, earnest pals who did just that. And I've had dealers confess their good luck, tinged with sadness, when some bloke staggers in on a Saturday (always a Saturday, it seems) and dumps a carload of gear on the showroom floor. Bargain basement day for "Dave's Fine Stereo" or "Perfect Sound Forever"... a bleak defeat for Alonzo who only wanted a musical retreat from secular pressures and the Little 
 
Lady's nagging encouragement for them to play Gin Rummy with Joe and Tarina Boffo down the street. 
 
Baling out, you ask yourself why it took so long to give up. You cash your feeble check, giving you back roughly 22.5% of what you invested on audio equipment... and take solace that the futile search for musical heaven is now buried without recourse. Goom-bye Krell mono-blocks. Sayonara Thiel thing-a-may-jigs. Hasta la vista all that Audio Quest spaghetti. The money extracted from the bale out is just about enough to repaint your 1979 Ford truck... a better investment, you think, after all the teasing agony.
 
Why not take your time?
 
Of course there's the radical alternative sitting right before you. Who said you ought to rush this inevitably incremental business of getting (making; crafting; nudging) great sound into your private realm?
 
Dorko, you need a "radical" alternative to (a) buying and swapping, then moving, selling, and hauling ever new gear only to (b) give up in frustration. Is that possible?
 
Sure it is, Slap Happy! Why not calm down awhile? How about putting your musical craving on idle and just learn what the hell is going on with ONE piece of gear. Only one… okay?
 
How about doing your due diligence (which comes in several forms of empirical and theoretical investigation)? Read the critics and reviewers you trust, no doubt for inadequate reasons; then borrow an amplifier, for example, that you think just might be a contender for your heart.
 
Next, listen to all sorts of sounds, musical genres, and dynamic textures. Get a feel for this piece of gear's characteristic audio footprint. Scope out, if possible, its quirks and virtues. I'm not kidding. I'm not making up this game of calibrated patience. It works.
 
But there's a trick to this subversive guerrilla war approach, you see. In order to "know" (experimentally, via the work of evidence gathering), you have to take notes on what you hear and what you listen to, at what volume levels, with what ancillary gear in tandem.
 
You begin there. Then what do you do?
 
Hint: you change one piece of accompanying equipment in your system. ONE. Only one and you want to choose which one component and which specific make and model of that replacement component you might gain insight into—say, your amplifier (are you with me here?).
 
Probably you're getting the point. There are virtually only two ways anyone lands a truly fantastic, mind-boggling, soul-shattering, heart-warming, erotically musical engine of sound reproduction: you get lucky on your first or second try at putting together a top to bottom system; or, like quantum-gravity research physicists everywhere, you isolate your potentially successful choices on purely theoretical grounds and then relentlessly trudge ahead with small increment as experiments in component matching—always keeping in front of you those crucial notes that are clear, detailed and reliably able to prevent you from repeating unneeded steps redundantly, all the while you enjoy (actually feel in control of) the process of scoping out how pieces of gear mix and match and miss but sometimes (every now and then) lock in together.
 
How about emulating Van Gough?
 
I mean that. Good ol' Vincent never had a Little Lady who tempted him to madness nagging his ass toward the Boffos' bloody Gin Rummy nonsense. Vincent Van Gogh was willing to drive himself nuts without any help. And that's your best option if you really want to put together a sound system that will constantly put you in a front row seat at La Scala or the Village Vanguard,
 
Seriously. Think about it. How else can you ever assemble the sort of audio world that is adequate to your musical lust unless you stalk its creation, piece by careful piece, just the way (at eighteen or twenty) you stalked Jane Smiley's alluring beauty once you'd both grown up…
 
You didn't climb any dumb ol' plum tree looking for a quick glimpse. You made sure (i) not to blow it with Jane by being rash; (ii) you mapped out a plan of engagement; (iii) you carried out your strategy without doubt or deviation; (iv) you suffered, therefore "savored," every moment of stealthy courtship; and (v) when you'd reached the inside realm that defined the object of your approach, you had your parts in order and your mojo working. Wink-wink.
 
It's the same damn thing with audio, Herkimer! You can't count on luck. Only rely on savvy, patience, evidence gathering, deliberate listening (experimentation along with note taking), thus executing your own perverse curiosity like a crazy man—like Van Gogh, who insisted that the object of his artistic love was to "consume" the French rural landscape.
 
Don't you get it? This audio beauty stuff, searching for "nirvana" or whatever, is much like the physicist's precise experimental research and the artist's crazed fulfillment of focused irrationality. No one ever proved that musical enjoyment at its highest and deepest incarnations is a sane event. Or normal. Or "productive" of anything but the fulfillment of your animal and angelic spirits brought together much like Nietzsche, in his youth, proposed Apollo's sunny rationality as the exact supplement for Dionysus's drunken inspiration.
 
If you want the whole sonic magilla, you gotta commit yourself to the research, Dumbo ! Both that and your final victory are devoted to the same culminating fulfillment: musical explosions of infinitely subtle mini-gradations of transparent bliss (or something like that—you decide how you want to cash in on your real "sweet spot," not the youthful one when you almost busted your head falling off the plum limb.
 
All that is prologue.
 
…to this: Robert Lee's finest creation, the Acoustic Zen Crescendo speakers. How could such acutely luscious sonic joy cost so little (NZ$24,795/pr)? Let's explore their bedrock realty.
 
Before we speculate on the bargain price of such high-performance behemoths, let's sort through concrete reasons these speakers are magical additions to a system patiently (sometimes not so patiently) evolving, again and again over nearly a quarter century, in the right direction; a system at moments lurching sideway but, for the most—when I finally "got it" (see above sections)—inching toward "real sound exactly representing live musical stages"—delivering music as it was made in live time and space, which has almost always been my asymptotic sonic Holy Grail. Damn near an impossible attainment, but not utterly, completely out of reach. I've approached that elusive reach several times only to diminish my approach by precisely the sort of arrogant or over-eager gear swaps castigated above.
 
What are these Crescendo speakers doing that is so "magical" you ask?
 
They get out of the way: they are essentially invisible to the forceful delicacy of sonic textures and dynamics. You get the slam and nuance of a live recording in three-dimensional space as if that space is three-dimensionally present right before your somewhat amazed witness;
 
The Crescendos are full-range, top to bottom, blockbusters that are astoundingly flat right at 20Hz and tip-toeing up to (and quite literally past) 20kHz;
 
The integration of each driver in this three-way transmission line "under hung" system is spooky: very few speakers, at any price, achieve the sonic coherence so effortlessly delivered here;
 
Ease of amplification is an index to the Crescendos' music-friendly affinity: at 90dB efficient, they can be driven to awe-inspiring sound pressure levels that do not break up or show evidence of distortion… a puzzle, in some very real sense, because—while the better the amp driving these big speakers, the better sonic results obtained—one can throw fairly inexpensive, undistinguished amps at them and discover remarkable musical output that, in my experience outflanks ANY speaker I have heard over a sustained listening period;
 
All of these virtues (and mysteries) notwithstanding, the sound stage mapped by the Crescendos appears as an innate, organic extension of the microphone techniques employed: to wit, a two mic Ortofon arrangement, well placed, accomplishes a sense of nearly infinite right to left (left-right) openness… as if, without phase cancellation of any sort, the recording simply delivers itself with a 180 degree sweep and directness that, rendered on speakers with such accuracy, feels very much like a surround sound presentation from only two boxes—a grand illusion, in fact "an illusion," but exactly the sonic and musical/staging illusion every recording engineer with an ounce of devotion to the ideal of "real music in real space" lives to create;
 
Monitor-grade acoustic accuracy is, in its own right, a "holy grail" ideal sought by recording engineers of varying kinds; but the rub, with such an ideal, has been the traditional use of single driver monitors in many (many) studios—sonic iteration that has been both degraded by inferior technology and essentially a "dual mono" signal delivery that vastly compromises what the ears laying tracks down in a studio (such as, for example, "Mad Hatter," Chick Corea's former studio). That noted, I will assert here that Robert Lee's Crescendo speakers are that rare thing: a full-range, musically engaging, soul-embracing signal delivery system without obvious warts or constraints that, simultaneously, offers monitor-grade, pristine acoustic accuracy {note: I await the next behemoth speaker able to match this counter-intuitive result};
 
Foot-patting, heart-throbbing musical joy: that is the balls-to-the-wall ultimate achievement of these speakers… they are thoroughly alluring when you listen to the Guarneri Quartet playing late Beethoven string quartets just as they are shockingly immediate when Duke Ellington's classic 1956 Newport concert locks into "Diminuendo in Blue and Crescendo in Blue." Paul Gonzalves takes more than a dozen gate-banging solos on tenor sax and the blonde woman in the front row of Peabody Park cranks into dancing high gear. You can feel why George Wein, the concert director, was on the verge on stopping action on stage. Thousands of screaming, roaring fans with libidinous mojo makes a startling force. You hear every bumping groan and ferocious stomp as if time ran backward and Newport's crazed mob as well as the Duke's throbbing big band sat right in front of you;
 
Low level sonic detail that escapes notice by veiled speaker performance stands up clear and proud through the Crescendos' affinity for replicating each whispered moment of sound, speech and music.
 
These speakers strapped into a home theater set up, flanking a large screen television (say @ 73" Mitsubishi), recreate the most hellacious, ass-kicking sonic booms, hisses, and floor-rattling thuds and whomps I have ever heard outside a public movie venue. You think your home theater set up is pretty good, I imagine. Terrific. Now challenge yourself and put these heavyweight blasting boxes in place. Then fasten your seat belt. Bruce Willis movies love these speakers. The new Barbara Streisand concert in Las Vegas on Blue Ray disc will blow you away: great camera work; excellent large scale audio recording work. You are there in the audience. Only better. Period.
 
While few will care as my (nutcase) self cares, the Crescendos reveal details of recording work that lesser speakers simply cannot divulge. An east coast recording partner sent me a disc with recent recordings he'd done. On the initial audition, I was sure that he had used Schoeps mics. I called to ask if that was accurate. Affirmative. My point is simple. Crescendos tell the sonic truth. The down side here, of course, is that—if you are playing well worn vinyl a great deal or have fallen in love with terrific music recorded with inferior gear or techniques—you'll "enjoy" your old favorites through the Crescendos with newfound appreciation for well-recorded albums.
 
Price tricks and treats: Happy Halloween!
 
I confess that I do not understand how Acoustic Zen arrived at the ridiculously low price point of $14,000/pair for speakers that are not only literally "world class" but that hold their own (and possibly, in some reproduction areas, surpass) very good and very, very expensive speakers—such as Dali's impressive "Megaline" speakers and MBL's 101.ii brilliantly sculptured speakers.
 
Wes Phillips at Stereophile once remarked that the test of a great speaker may well be if you find that once it resides in your listening world, you cannot (or do not want to) "live without it." I'll conclude the first part of this two part review by agreeing with Wes' aesthetic outlook, wondering simultaneously how Robert Lee's gang at Acoustic Zen is able to deliver the Crescendos at retail for $14,000. My best speculation is that someone is giving them a break on costs that do not translate into inferior materials or construction/build. Or, perhaps, they have calculated the lousy economic context for audio survival at present and accept less in return in order to compete against a veritable glut of high-end speakers on the audiophile market. If that is the case, then the Crescendo speaker represents not only a genuine bargain for discerning audio buyers, but something close to charity on the part of Robert and Benton Lee, two cheerful brothers whose generous and optimistic outlooks help to define the best of a bad time for audiophile reality.
 
I do not want to proceed further without these speakers. And so stay they will, exactly where they now reside: at the heart of my listening and mastering universe… a place where simple pleasure often is second to the hard work of evaluating gear, including scrupulous assessment of my own recordings. I do not want to live without the Crescendos and so I won't. But in some way, at once irritating and doubtless inevitable, I find that I cannot proceed apace without them since they've solved so many logistical audio problems for me over the last four months of constant use and evaluation. 
 
And yet I'm nagged by this elemental existential question: why did it take so long? Why did I have to wait into my ferocious and cranky geriatric-hood to snag a pair of 'take no prisoners' music reproduction savants? Do you think it's been fun hauling heavy speaker boxes in and out for twenty-plus years? Do you want to copy my bad habits? I wouldn't think so. Thus, I suggest you forget my example and perhaps my recommendation, too, and just do it your own way with elegant savvy waiting for the long odds of sheer good luck to land in your lap.
 
Yet again… the Acoustic Zen Crescendos are alluringly seductive and, in a world where you could (if you were able to) pop a quarter million dollars down for a pair of fancy speakers that may or may not have soul or magic, you're better off checking out these Rolls Royce boxes in their various gorgeous wood finishes. I hate to be right about this because it may put your butt in the musical sweet spot more often and then your Little Lady will be unhappy. You might also put on a few pounds because Balvenie tastes so much better with great sound, especially right before you want it. Then you'll be cranky.
 
As a momentary "final word" before I soon write the second part of this report, I'll note merely this: if the sky's limitless horizon is the only permanent background for thought and knowledge, then speakers as refined and bold as the Crescendos are demonic companions for knowledge and thought… with a feeling enhanced by the exotic perfection of the sky's endless reach. 
Chip Stern of 6Moons Interview with Robert Lee of Acoustic Zen
Chip Stern
Between the two drivers, is one handling low frequencies and the other both midrange and bass as in a 2.5 way design?
 
No. It is a true D'Appolito-style array. Both 6.5" drivers are wired in parallel and handle 30Hz to 3000Hz. This style design employs two low-frequency drivers with a tweeter in the center. Such a configuration creates a larger sweet spot. It gives you greater low-frequency extension along with two-way coherence.
 
Tell me about your woofers. How does an underhung driver differ from a well-hung driver?
 
Underhung means that it has a very short voice coil in a large magnetic field gap. The drivers are top grade and so are the magnets. The voice coils are very narrow and always move in a linear manner within a magnetic field regardless of excursion. Additionally, a traditional long voice coil moving in a short magnetic gap presents a high variable impedance to the amplifier.
 
Can you break it down in some more detail?
 
With a short voice coil in a long magnetic gap, as the music signal flows through the voice coil, the coil and the cone moving together produce the sound wave. A long magnetic gap structure offers a much wider linear magnetic flux density, alternately pushing and pulling the short voice coil back and forth. Since the magnetic force on the coil is constant and completely symmetrical with the motion of the piston assembly, the result is a sound wave with extremely low distortion and coloration, allowing it to respond much faster to a transient signal and to stop faster after the drive signal has ceased.
 
Compare that with the large signal behavior of high-excursion overhung transducers. Because the coil extends beyond the control of the magnetic flux field, it causes very high harmonic and transient distortion that can reach 5 - 20% whereas the underhung driver maxes out at 1%. Because of the very complex magnetic structure and complications involved in voice coil placement and fabrication, the underhung voice coil is difficult and expensive to fabricate.


What are the speaker cones made of?

 
They use a ceramic-impregnated fabric in the center with ceramic coating on either side to form a sandwich. These drivers are custom built for Acoustic Zen to my specifications. The ceramic coating makes for a strong, dense, rigid surface area that will not break up nor produce a lot of ringing. The cone is very stiff and light and as a result, very fast. It responds immediately to a signal and returns to its original position very quickly. This minimizes frequency overhang, colorations and distortions.
 
Why a Neodymium magnet?
 
An underhung driver's voice coil requires an extremely strong magnetic field. If you are using traditional magnets, the size and weight of the motor would be excessive. Neodymium allows us to maximize magnetic coverage while controlling weight and size.
 
Why did you choose a ribbon tweeter and how does your circular design differ from other approaches?
 
I don't want to get too technical here. My circular ribbon tweeter design, unlike a traditional dome or cone tweeter, presents a purely resistive impedance that's completely linear in the audio range. It also has an essentially linear phase response, which contributes to an immediate and precise response to any transients in a complicated music signal. This dramatically reduces distortion and coloration.
 
I am using the thinnest diaphragm possible, a 0.01 millimeter Kapton diaphragm. That's just about weightless, with a 95% covered aluminum circle of conductors across the entire vibrating area positioned between super strong Neodymium magnets. Some people use metal ribbons which can result in very harsh HF response. Kapton is not only extremely light, it is also heat resistant, hence the thermal behavior of the voice coil will not translate into audible distortions. My tweeter's larger circular membrane not only provides much higher power handling and a wider frequency response, it also eliminates the offsets between horizontal and vertical dispersion that are common with narrow ribbons.
 
What kind of crossover are you using?
 
We employ a symmetrical 18dB/octave 3rd-order high and low pass.
 
Some people believe that a simpler crossover gives greater sonic purity - that the more complex the crossover, the less natural the sound.
 
A 1st-order network would have been impossible in this system because of the overlap of frequencies. You have to use a very complicated audio circuit to filter down the frequencies that will cause issues with both impedance curves and distortion. Because our crossover point at 3000Hz is fairly high, we don't want the tweeter to handle midrange frequencies or vice versa. We want the woofers to cut off almost immediately. Because of the kind of speed and accuracy we wanted to achieve in the low frequencies, a 6.5" driver offered the best balance of linearity, frequency extension and speed. Larger drivers would cause other problems when paired with a 1.5" circular ribbon tweeter.
 
What was your thinking in terms of the shape of the cabinet where it gradually narrows toward the back?
 
The shape of the cabinet and the reduced size of the acoustic chamber/line subtract by almost 90% the back waves, standing waves and other distortions reflecting back to the drivers. The shape of the cabinet and the time-aligned vertical driver array reduce driver diffractions while providing a good acoustic center which improves soundstaging.
 
The sides of the cabinet are 1" MDF while the mid/woofer front baffles add up to a total of nearly 2" depth. Between the baffle and the cabinet face, there is an additional layer of decoupling damping material to absorb driver motion.
Tell me about the transmission line.
 
The use of a transmission line greatly increases low-frequency extension and minimizes the impedance peaks we see in ported alignments.
 
Why only one set of speaker terminals?
 
I am using our Acoustic Zen Satori speaker cabling for hookup wire which is 10 AWG/6N zero crystal copper. That is far better cabling than most people have going from their amplifier to their speaker. I really do not want for people to alter these relationships. I have already fine-tuned the frequency response and tweaked all phase adjustments. If somebody employs a bi-wire setup, it could alter the overall balance so I prefer a very simple, direct connection.
 
If you have unlimited funds and unlimited size, you can make your loudspeaker do anything you want. Then you can end up with a Wilson Audio Alexandria, which was pretty bloody awe-inspiring when I heard it in a tuned room at Innovative Audio in New York. But why the hell shouldn't it be? It costs $125,000/pr, weighs several hundred pounds and is taller than Wilt Chamberlain. There are no practical limitations. I found that your speaker had some of the best attributes of a good two-way and a floorstander. Still, at its $4,300 price, there have to be some compromises. What were the relative trade-offs you had to address? The Adagio does more things well than most speakers I've heard at its price yet naturally, it won't have the frequency extension of a Vandersteen Quattro with its built-in subwoofer. Nor does it have the immense soundstage and ambience retrieval of the Dynaudio Confidence C1. However, both are more specialized speakers and both are significantly more expensive.
 
That is a good point and I would like to say this. There are thousands of speaker manufacturers worldwide but so far I have identified less that ten who employ underhung drivers. I think that underhung drivers are the best solution to reduce harmonic distortion in the bass. No one ever talks about the huge amounts of THD in the low frequencies, especially when you are playing things loud. Most drivers create from 10-12% THD when you listen at over 10 watts. If you are listening to 10 watts through your speaker system, you get 5% harmonic distortion. So what are you listening to? When people design amplifiers, they rate them at 0.05% harmonic distortion. Meanwhile even at modest volume levels, your low-frequency drivers put out 5% or greater harmonic distortion so nobody can listen at even low levels and achieve true purity with low distortion, never mind concert levels.
 
That's why I selected to use both the underhung driver and a ribbon tweeter of my own design. The advantage of ribbon tweeters is their low distortion. The drivers in the Adagios result in what I believe to be the lowest distortion loudspeaker system in the world - at any price. People are so concerned over distortion figures in their amplifiers and CD players and would never dream of accepting the levels of distortion their speakers routinely put out. Most audiophiles remain unaware of this simple truth.
 
Even when speaker makers achieve good phase coherence, they are still using high distortion drivers for low frequencies that impact the quality of the signal. When listeners hear the resolution and low distortion achievable by underhung drivers, I predict many other manufacturers will follow suit and employ them. It's like the use of single crystal copper which Acoustic Zen helped popularize in cables. Now many manufacturers employ single crystal copper and silver.
 
The only company doing something like I am doing now (using ribbon tweeters and underhung drivers) is Wisdom Audio. And their top-line speakers are far more expensive. Thiel has been at the forefront in this arena but they feature a different style of tweeter/midrange. So the Adagio is really a very unique loudspeaker product. At only four feet high, it is a very good speaker for the average rooms most people actually have. Unless you use a very, very large room, the Adagio should be just right for most real-world listening environments. People have been taught that they should get a really large speaker that has the potential to excite plenty of reflections from wall to wall; to excite bass frequencies and room nodes; to produce all manner of colorations and frequency cancellations. Not the Adagio. It is perfect for 15-20 foot rooms.
 
Without neighbors getting most of the bass [laughter]. Obviously, there are speakers that will do certain things better, yes?
 
I am already working on a subwoofer that will match the Adagios perfectly, handle all frequencies below 60Hz and go down cleanly to 18Hz. I think the only thing the Adagios cannot do is give you that punch and pressure and power below 30Hz. Yet you can still hear the bass clearly all the way to the bottom of the piano and when the low frequencies stop, the drivers stop instantaneously. There is a minimum of uncontrolled motion and overhang. That is another advantage of underhung woofers.
 
Your bass drivers do stop on a dime, with no discernible overhang. And the tweeter is not bright at all.
 
Other things that are very important to me as a designer are the phase and impedance curves. I think those are far more important than ultimate SPLs. You want those curves to be as flat as possible so you don't place a terrible strain on the amplifier. My phase curve is essentially flat from 10Hz to 40kHz. And the nominal impedance of the Adagios is 5 ohms. It is most flat from 100Hz to 10kHz, almost a straight line keeping within that 5 ohm impedance. You don't have different frequencies displaying wildly fluctuating impedances. Impedance is like resistance. So if different frequencies display different levels of resistance, the amplifier reacts and distortion is the result. As audio designers, we must reduce distortions wherever we find it to make the experience of listening to music more involving. That is the ultimate goal.
 
..........Chip Stern and Robert Lee 

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