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In Reply to: AudioKinesis Zephrin 46 custom paint posted by Brian Walsh on August 15, 2014 at 10:00:05:
Please accept my apologize for crashing this lovely party, and even worse, a bit late.I developed the radiation pattern employed in Zephrin 46 and Dream Maker LCS, which stands for Late Ceiling Splash. The end of the following thread has links to comments by pro reviewers at 2014 Newport THE Show: http://www.audiocircle.com/index.php?topic=125924.new;topicseen#new
Z46 employs no TL. Each channel of LCS requires two completely separate loudspeaker systems. Z46 houses both channels in one enclosure.
The foundation of LCS is an all-new radiation pattern unlike anything before.
Frosting on the cake is that one stereo pair of an LCS system comprises four separate bass systems. Because each bass system occupies its own unique geographic space, either the L or R (never both) LCS speaker wires with its electrical polarity inverted to damp bass modes. Because LCS output delays at least 10ms vs. on-axis signal from the so-called "Main Speakers," inverting the polarity of one LCS channel is inaudible in the mid/treble range. This feature provides a portion of the natural 3-dimensional bass mode damping feature of a 4-piece Distributed Sub Array. (Side note for attendees at 2013 RMAF who sampled Dream Maker LCS. We did not experiment with this bass mode damping feature till after that show.)
Dr. Floyd Toole and Dr. Earl Geddes associate the following qualities with ideal reverberant field:
1. Full range
2. High output relative to on-axis signal
3. Delayed 10ms-20ms relative to on-axis signal
4. Highly decorrelated relative to on-axis signalLCS provides the above qualities (especially #4) to greater degree than any other radiation pattern and any other loudspeaker. Tekton and Lowther share little if any LCS design philosophy.
The load impedance for each section of Z46 is 16 Ohm, and both impedance curves are very linear above the bass range. Sensitivity is the low 90 dB range. We used two amps at Newport THE Show, one being Atma-Sphere M60, the other a 10-12W transformer coupled tube amp. Neither amp clipped.
The 16 Ohm loads can wire either in series (32 Ohm) or parallel (8 Ohm). It's interesting to note that the higher the load impedance the less is the ratio of speaker cable series resistance relative to the entire load (speaker + cable). The lower is this ratio the less is the audible effect of the cable, with commensurate performance gain.
Ralph's sweet little S30 OTL makes about 40W+ into 32 Ohm load. SS amps make only 1/4 their 8 Ohm power into 32 Ohm, but current capacity increases and distortion spectra improves (less odd order harmonic distortion).
I've got Zephrin 46 setup in my 26 x 16 dedicated dead-quiet well-treated sound room 80 minutes NE of Salt Lake City. Also have Dream Maker LCS but waiting on new smaller LCS 2.0 speakers from Duke.
Note: we intend to offer the new smaller LCS speakers to add to any pre-existing loudspeakers, even dipole and bipole systems. In this case, a power amp with level control is required to drive LCS and match level with the Main Speakers. Price is $2900/pr for the LCS speakers. Sensitivity is low 90 dB range. As per Duke's long standing design philosophy, this new LCS speaker is an easy load with linear impedance curve above the bass range. We estimate bass cutoff "low 30 Hz" with some vertical boundary reinforcement (remember LCS loads directly to the floor, firing upward toward ceiling).
LCS lowers bass cutoff when added to many loudspeakers, dare we say most. More critical than simply lowering bass cutoff and increasing bass power, LCS minimizes bass mode effects, improving bass timing and quality by physically minimizing mode effects in three dimensional space throughout the entire room. Digital EQ manipulates phase, SPL, and frequency in the line level, but it's a zero sum game. Performance degrades at points in the room other than mic test points.
Dual use 2-ch/HT applications: if you ever heard well recorded music played on even the most costly HT system, you were likely unimpressed. I won't explain here why HT loudspeaker architecture is anathema for music. Another Z46 benefit is to allow, for the first time, a dual use 2-ch/HT system with no compromise in either format. Beyond "no compromise," LCS provides rare combination of performance features in 2-ch. For HT applications Front L/R Z46 "phantom center channel" equals any Front LCR array. For music in HT application we believe Front L/R Z46 outperforms any HT Front LCR array regardless of cost or complexity.
James Romeyn, Providence UT
Edits: 09/05/14 09/05/14
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- RE: AudioKinesis Zephrin 46 custom paint - ro7939 22:31:05 09/04/14 (0)
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