I am a long-time student of loudspeaker design and psychoacoustics, and have been a dealer for almost eight years now. I have a couple of speaker designs that I sell direct, and my top-of-the-line speakers are the Jazz Modules.
First, a couple of pictures. Here I am at the Rocky Mountain Audio Fest, posing with two of the finest people in audio today (thanks, Chris!):
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=865&pos=71And next from the Lone Star Audio fest - that fish was this big, I swear! (courtesy of Jeff):
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1086&pos=3Okay, back to the matter at hand...
The Jazz Modules are designed to do well in areas that are traditionally recognized as being important, such as smooth frequency response, good bandwidth, and freedom from coloration. But the design also emphasizes performance in several areas that are typically not given high priority:
1. The reverberant field has approximately the same spectral balance as the first-arrival sound. This is important for two reasons: First, since most of the energy that reaches our ears in a normal listening room is reverberant energy, natural-sounding timbre (tonal and textural quality of voices and instruments) cannot exist if the reverberant energy is skewed in spectral balance. Second, if there is a significant discrepancy between the first-arrival and reverberant sound, the eventual result is listening fatigue. You see, the ear/brain system is constantantly comparing first-arrival and reverberant sounds as it sorts out the directional cues, and the brain has to work harder to properly classify reverberant energy if it's spectrally dissimilar from the first-arrival sound. This is one of the reasons many speakers can literally give you a headache if you listen for a long time. The Jazz Modules are non-fatiguing over the long haul. The design features that get the reverberant field right are the 90-degree constant-directivity waveguide which keeps the radiation pattern above the 1.7 kHz crossover region extremely uniform, and then the lower frequencies are handled by a 10" woofer whose radiation pattern has narrowed to 90 degrees at the crossover frequency - so there is no radiation pattern discontinuity in the crossover region (which is present in most multi-driver speakers).
2. The Jazz Modules use very high quality prosound drivers that have negligible power compression at normal in-home listening levels. Typical home audio speakers not only suffer from audible power compression which robs the music of dynamic life, but the drivers also typically have differing power compression characteristics such that the tonal balance changes with volume level.
3. The Jazz Modules are designed to be more room-adaptable than most speakers. The bass tuning can be varied by the user by changing the port length, and the high treble balance can be adjusted via an innovative external resistor feature. The port is on the rear of the enclosure primarily because some midrange coloration is possible if a long port length is used (think of talking through a cardboard tube - it's not that bad because of damping material in the cabinet, but you get the idea), and this way any coloration emerging from the port is at least pointed away from the listener. The high frequency balance can be adjusted via a single high-quality resistor mounted in a rectangular cup on the rear of the enclosure. The external resistor is bypassing a resistor in the crossover, and acts more as a high frequency "tilt" control than as a wideband "shelving" control (which is what an L-pad does). This avoids the questionable sonics of an L-pad while giving the user the ability to tailor the high frequency balance according to his system and room. For instance, I use a different resistor with a solid state amp than with a tube amp.
4. When set up as intended (with about 45 degrees of toe-in), the Jazz Modules give good soundstaging over a wide listening area as well as good timbre throughout the room. The ear localizes sound by two mechanisms - arrival time and intensity. With the typical slight-toe-in placement, as the listener moves off to one side the soundstage shifts faster than he does. This is because the near speaker is not only winning arrival time, but also intensity because the listener is moving more on-axis of that nearer speaker, where the high frequency energy is more prominent (we get our localization cues mostly from high frequencies). With the 45 degree toe-in of the Jazz Modules, for the off-center listener the nearer speaker of course wins arrival time but the far speaker wins intensity because the listener is now more on-axis of the far speaker and more off-axis of the near speaker. It's not perfect, but it does work well. The tradeoff is, with this setup the imaging isn't quite as good in the middle of the sweet spot as it would be if the speakers were aimed right at the listener. Of course, the owner would have the option of setting them up any way he wants.
5. The Jazz Modules are exceptionally amplifier-friendly. Above the bass impedance peaks (inevitable in a reflex enclosure), the impedance varies smoothly between 8 and 12 ohms. Check out Soundstage's published measurements of other speakers and see how rare this sort of smoothness is. I designed these speakers on an Atma-Sphere S-30 OTL amplifier, but double-checked using a Nuforce amp to make sure they'd work well with a wide variety of amps. My most recent customer (as of this writing) happens to be a single-ended triode amplifier manufacturer. Now the efficiency is only 92 dB so it's not super-high; that's a trade-off I made taking box size and bass extension into account. It may not be the optimum tradeoff balance for everyone of course.
A few comments about the waveguide are in order. Many audiophiles cringe at the thought of a horn-like device, as they have memories of harsh and fatiguing presentations from hornspeakers. Briefly, there are three types of coloration induced by horns (which I won't bore you with here). Two of these are eliminated by the waveguide's design and/or the crossover I developed (yes, I do my own crossovers). The third type is reduced by the waveguide design to the point where it is inaudible at normal listening levels, but will probably be audible at very high levels (it's an acoustic phenomenon that cannot be addressed in the crossover). So I haven't achieved absolute perfection, but so far I haven't had anyone tell me that they hear "horn coloration" in my design.
Of course ad copy is cheap (in my case very cheap - I write my own ads, and this one was free!); real-world ears-on performance is something else. Here are links to online commentary about my speakers from last year's Rocky Mountain Audio Fest, T.H.E. Show in Las Vegas (concurrent with CES), and the Lone Star Audio Fest held in Dallas a few months ago. Some of the commentary includes Stormbringer, another speaker I manufacture that's conceptually identical but uses a less expensive woofer.
All of this is unsolicited, and I'm pretty proud of it:
http://www.enjoythemusic.com/rmaf2006/warnke/ (Scroll down about halfway.)
http://blog.stereophile.com/rmaf2006//index1.html (Scroll down about 1/4 of the way.)
http://www.sonicflare.com/archives/vegas07-prosound-lurkers-audio-kinesis.phphttp://www.stereotimes.com/CES07DS.shtml (Scroll down about 1/4 of the way; this page is sometimes slow to load. Commentary is about the latest version of my Stormbringer, but it's a very similar speaker as you can see.)
http://www.cryo-parts.com/lsaf2007.html (I have no business relationship with Lee of Cryoparts; the Sonicweld speakers he refers to are sixty grand a pair.)
http://www.audiocircle.com/index.php?topic=40572.10 (See comments by EDS.)
At this time, I have Jazz Modules available in three finishes: Walnut, Maple, and Black. The Walnut and Maple speakers are $4500 a pair; the Black (painted) is $4000 a pair. If I were selling through normal retail channels, the price would be roughly double what I'm asking (assuming 40 points for the dealer, and I'd have to launch an expensive advertising campaign in order to support my dealers properly).
Finally, here are some specs:
Type: Reflex-loaded two-way
Driver complement: Alnico magnet Pioneer TAD woofer with treated paper cone; neodymium magnet Beyma compression driver with polyester diaphragm
Frequency response: Any loudspeaker's low frequency extension is highly dependent on room acoustics, but with worst-case scenario acoustics the Jazz Modules can be tuned to give extension to about 40 Hz. Under favorable conditions, bass extends into the upper 20's. High frequency extension goes out to 17.5 kHz.
Impedance: Nominally 8 ohms; impedance never drops below 8 ohms, nor rises above 12 ohms except in the bass region where there twin impedance peaks associated with the reflex tuning.
Efficiency: 92 dB/1 watt input (into nominal 8 ohms impedance).
Recommended amplifier power: Minimum 5 watts (depending on your listening style); maximum input 400 watts unclipped.
Dimensions: 42 inches tall by 14.5 inches wide by 17.5 inches deep.
Weight: About 110 pounds (I've never actually stepped onto a scale with one; this is calculated).
If you happen to live within a day's drive of south-eastern Idaho, I'm willing to bring a pair of Jazz Modules to you for an in-home audition. If you live more than a day's drive away, ask anyway and maybe I can find a way to work it in.
Feel free to ask me any questions, and thanks for taking a look.
