AudioKinesis, my “house brand”, is the label I put on loudspeakers of my own design.  I place a lot of emphasis on getting the reverberant field right and minimizing power compression, and try to do so in a package that your wife just might let you put in her living room.   Emphasis is on value and performance rather than a big profit margin.  I will try very hard to get you an audition if you’re interested - I’m willing to drive hundreds of miles to give you an in-home audition, and if you live farther away than that give me a holler anyway and maybe I can come up with something. 

Models:

• Jazz Module
  
• Dream Maker

Background

As a long-time amateur speaker builder, over the years I’ve accumulated a few ideas about what goes into a good loudspeaker design.  Now these ideas are hardly original, but many of them are still more the exception than the rule.  My design goals are:

1. Uniform radiation pattern over much of the spectrum.  This results in a reverberant field with a correct spectral balance, which contributes to natural timbre and long-term fatigue-free listening.
    
2. Freedom from dynamic compression. Musicians use dynamic contrast to convey emotion, so a speaker that is free from dynamic compression at normal in-home volume levels will do a better job of conveying that emotion, all else being equal.
    
3. Freedom from coloration, including box internal resonances, panel resonances, driver resonances, and audibly significant frequency response aberrations.
    
4. SET and OTL friendly impedance curve.  Some of the finest sounding amplifiers out there have a fairly high output impedance, so we try to keep the impedance curve above 8 ohms and as smooth as possible.
    
5. A reasonable balance between efficiency, bass extension, and box size (which is closely related to WAF).  My speakers can’t possibly be all things to all people, but hopefully they’ll be enough things to enough people for me to make a few sales.
    
6. Good value.  My parts cost is approximately 60% of the price that I ask, and that doesn’t include the time I put into them (fortunately I don’t build the cabinets, though I do work on the interiors).  Of course all that means nothing if the speakers suck, so I’ve worked very hard to put together a good combination of drivers, enclosure, and crossover design.

Any dealer’s house-brand speakers typically get looked at with suspicion, so I expect that.  No offense taken.  My hope is that, if it looks like my designs might meet your criteria, you’ll contact me about them.  If we both conclude that one of my designs looks like a good possibility, we can work on finding a way to get you an audition.

The Jazz Modules offer a somewhat unorthodox approach to realistically recreating natural timbre and dynamic contrast over a fairly wide listening area in a reasonably-sized package.

Natural timbre arises from smooth frequency response, but to really get the timbre right requires attention to both the on-axis response and the summed omnidirectional response.  The summed omnidirectional response is often called the “power response” and is important because it dominates the spectral balance of the reverberant sound (which in turn dominates the perceived tonal balance in most in-home applications).  It’s not enough just to get the first-arrival sound right.  In the Jazz Modules we have gone to great lengths to also get the reverberant sound right, using a constant directivity waveguide crossed over to a 10" woofer where their directivities converge.
 
Dynamic contrast is maintained by using high quality prosound drivers that have negligible power compression at normal listening levels.  Sound pressure levels up to 112 dB are reproduced with less than 1 dB of power compression.  The woofer uses an alnico magnet and the compression driver uses a neodymium magnet, both chosen for their improved dynamic flux linearity over conventional magnet structures (which translates into less distortion and less power compression).  The tradeoff is that alnico magnets can be damaged by overheating (neodymium also, but the limiting factor is the woofer’s magnet), so it is highly recommended that you not exceed the maximum input wattage figures for the Jazz Modules. 

Note that power compression specifications are almost never reported for loudspeakers intended for home audio use.  It’s a dirty little secret that many high-end loudspeakers are already compressing significantly at normal in-home loudness levels, such that what should be a 20-dB peak often ends up being no more than a 16-dB peak.  This robs music of its liveliness and emotion, since performers often use variations in loudness to convey emotion.

Many people find it necessary to place speakers close to a wall, or even near a corner, which can result in boomy bass if the speakers weren’t designed for such placement. The bass tuning of the Jazz Modules is user-adjustable, which adds a lot of placement flexibility and amplifier compatibility. The treble can also be gently tilted to adapt to room acoustics.

The width of a loudspeaker’s sweet spot is a function of its radiation pattern, and the Jazz Modules have uniform radiation over a 90 degree arc.  The recommended setup is with the speakers strongly toed in so that their axes actually cross in front of the listening area.  This preserves good soundstaging for listeners seated well to either side of the centerline, and minimizes early sidewall reflections (which can be especially detrimental to imaging). 

Unlike most earlier generation horns, the waveguide used in the Jazz Modules is a very low coloration device.  A constant-directivity horn or waveguide is the most practical way to get the power response to closely track the on-axis response.  

The net result is a loudspeaker that pays a lot of attention to getting the timbre and dynamics right without imposing distracting colorations.

Thanks for taking a look.

Duke LeJeune

JAZZ MODULE SPECIFICATIONS:

Manufactured by:

AudioKinesis
Preston, Idaho
(208) 852-2610

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The Dream Maker takes an innovative approach to music reproduction that gives greater weight to psychoacoustic considerations than most contemporary designs do.

One of the biggest differences between live and reproduced music is the nature of the reverberant field. Compared to what we normally experience in a home listening room, in a good live music venue the reverberant field begins to arrive much later and is much more densely energized, and also decays more slowly. In addition, in a good recital hall the spectral balance of this reverberant energy does not depart significantly from that of the first-arrival sound.

Research confirms that a well-energized, spectrally correct, late-arriving reverberant field is indeed beneficial in smaller rooms as well. However, not all reflections are beneficial even if they are spectrally correct; reflections arriving earlier than 10 milliseconds after the direct sound tend to be detrimental to tonality, clarity, and imaging. On the other hand, reflections arriving later than 10 milliseconds behind the direct sound add richness and liveliness and a sense of envelopment with little or no detriment. Now this10 millisecond interval - corresponding to a path length difference of 11 feet - is not a hard-and-fast barrier; rather, it’s more like a fuzzy transition zone.

With normal forward-firing loudspeakers, the relative amount of late-arriving reverberant energy is much too low to approximate the sound field we’d experience at a live performance. Unusually wide-pattern (or even omnidirectional) loudspeakers will improve the relative level of energy in the reverberant field, but in many cases increase the amount of undesirable early reflections. In addition, omnidirectional systems often give exaggerated image size for solo instruments. Dipolar radiators come closer to the ideal, as the additional reverberant energy from their rear radiation is directional enough that its arrival time can be controlled simply by positioning the speakers far enough out from the wall behind them. Owners of dipoles have often observed that their speakers sound much better with about 5 or 6 feet of space behind them than they do close to the wall, as predicted by our psychoacoustic observations in the preceding paragraph.

The Dream Makers use a controlled-pattern bipolar configuration, as this gives greater dynamic impact and amplifier compatibility than a comparably-sized dipole would. The radiation pattern is 90 degrees front and back, which just happens to mimic the radiation pattern of the legendary SoundLab A-1. In addition, Dream Maker’s rear-firing drivers are vertically offset relative to the front-firing ones, which smoothes the in-room response in the bass region. Recommended set-up calls for positioning the speakers a good 5 or 6 feet out from the wall behind them, along with a very large amount of toe-in (typically 45 degrees or so). This extreme toe-in avoids the early sidewall reflection and gives a much wider than normal sweet spot without exaggerated image size. The result is uncannily life-like reproduction because the Dream Makers are working with your ears and room instead of against them.

The Dream Makers made their debut at the 2007 Rocky Mountain Audio Fest in Denver. Here are a couple of comments from people who listened to them extensively:

“Of all the rooms at the show, big or small, this room, and Duke's speakers, were the finest thing I heard. They invited the listener into the music and presented a wonderful soundstage that felt as if I was there.” - Thomas Portney, blog on Stereophile.com,

“My favorite of all the speakers at the show was the AudioKinesis - and in a very difficult room, too. I very much enjoyed listening to my Mercury "Picture at an Exhibition" disc at Row 15 playback levels - this is a CD that is nearly unplayable on most hifi systems due to the extreme slewing requirements on DAC converters, amplifiers, and speakers.” Lynn Olson, post on diyaudio.com.

The Dream Makers present an amplifier with an easy 16-ohm load, and the efficiency is a real-world-friendly 92 dB. The bass tuning is user-adjustable to allow tailoring for room acoustics and/or amplifier output impedance, and the treble tilt can be fine-tuned by the user. The Dream Makers were designed on the Atma-Sphere S-30 OTL amplifier but will work well with many other specialty tube amps, as well as with virtually any solid state amp.

If you have the room available to set them up correctly, the Dream Makers are competitive with well-designed loudspeaker systems retailing for two or three times their price.

DREAM MAKER SPECIFICATIONS

Manufactured by:

AudioKinesis
Preston, Idaho
(208) 852-2610

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