Diapason Ensemble

Loudspeaker Description

Double Eagle Stereo Subwoofer

   Since the introduction of the "Contra-Bombarde”, we have had the notion of producing a smaller, more cost effective stereo subwoofer. It finally dawned on us to adapt the OBELISK'S unique hybrid transmission line bass chamber to a twin back-to-back configuration. The east/west driver position and rear-mounted passive radiators have many advantages and offer a modular flexibility as well as reduced cost. A single unit (stereo) can be used with simple passive low-pass filters (included), for a 3-unit satellite-type system, or as an add-on to existing full-range systems to augment the bass and reduce distortion. Further, two units can be bridged to mono, yielding left and right channel dual woofers for even more power handling and lower distortion with a lower 3 dB cutoff. And all this can be accomplished without the absolute need of an electronic crossover, plus power amp for the bass. A passive input filter module is available (3-position) for a variety of satellite options. Special impedance variations may be considered for commercial stacking applications.

Diapason Module

   The "Diapason" is without a doubt the crowning piece of our art. A wisp of an idea, expanded over a span of 25 years, has culminated into the speaker of my dreams. We humbly dedicate it to the memory of our late friend and mentor, A. Stewart Hegeman. The “Diapason” reveals the enduring impact he has had on our work. I believe he'd be pleased to know his influence has not, and will not, be ignored. Following his particular vision has been costly. Why have we, then?

   We're convinced he was on the right track all along, just like Armstrong, Crosby, Enckel, Olson, Cook, etc., and let's not forget the cosmic elf, Buckminster Fuller, also regarded as something of a relic. The sophisticates have passed by these ancients, it seems, in order to forge their own brilliant identities. Perhaps we weren't keen enough to do the same, and lagged behind to absorb what we might, from these old "has-beens." What a wealth of treasure they have left us! How can the whole of the loudspeaker community have ignored such a trove?… Ego? Ignorance?

   Indulge us but again as we repeat ad nauseam: A conventional, forward-throwing loudspeaker cannot begin to replicate the waveforms produced by natural musical instruments, period. Nor, for that matter, any other sound made in the universe! Since we must agree that any sound has a polyradial trajectory away from its point of source, we are forced to conclude that a reproductive source, if it is to approximate accuracy, must attempt a similar disposition. A conventional box loud speaker does not even try! It has already failed on the drawing board.

   Preposterous, you say! Why are there so many of them and only one of us? Don't know...mystifies us at times…laws of physics, acoustics, accessible to all...puzzling.

   However, just because one stands alone, this ought not discredit one's achievements. Noah, and only his family, entered the ark. And only they survived the flood. Any and all were welcome, but declined. We are not merely whimsical about our somewhat solitary divergence, but are certain of its fundamental veracity. May we assert that a simple demonstration of the "Diapason" will do all that is required to convince anyone that this is the only way a loudspeaker can attempt a re-creation of an actual sonic waveform. (By “only” we mean to establish a new generic identity for a methodology of procedures. Variants of design may surely be employed in pursuit of the goal, as several of our other speakers do.)

   Further, I'm certain that my design concepts and conclusions are inspired and invested with a particular sense of the orchestra. (If not prepared to describe procedures and formulas, I can assure you that I am keenly aware of the ongoing metamorphosis.) I suppose I'm saying that there is no unique activity that does not depend on clues and hints left behind, incomplete, by others (Mozart for Beethoven, for example). For me the great challenge has always been the symphony orchestra. I will not write thousands of words describing my impressions of an orchestra, except to say that it can do almost anything sonically, from a whisper to a roar. In a concert hall this relates to three-dimensional sensations. Why, at home, settle for less? Hegeman understood this aspect of three-dimensional spatial distribution completely, as evidenced by his work, and thoughts, which he shared. He died long before the "Diapason" was started, but his influence seemed stronger than before.

   The "Diapason" is a veritable confluence of ideas that reach all the way back to Rice and Kellogg. After several years of thought, the first active prototype was built in 1971. A small amount of tinkering followed, and a year or so later it was put away in mothballs to gestate. For 16 years it just nagged away at a corner of my brain and then, in a flash, it just was. The day before, nothing. The ideas and details came in torrents and the development went at a fever pitch. In about six months we were close to conclusion and I knew we had something quite different and beyond what we had expected.

   It is now many years since the public showing of the final prototype, and the consensus of critical opinion is astounding; each owner has described it as his "final speaker"! Many have said they are so absorbed in listening to the music, the shortcomings of previous loudspeakers having vanished. Some experienced professionals regard it as the finest domestic loudspeaker ever produced. Unfortunately, for some, it is not costly enough to merit serious consideration. It has made us delirious with pride and joy. You all know the classic disease of all designers: never happy, never finished! Well, I'm even healing from that one. I've always listened to recorded music with one-half of my faculties discerning faults, weaknesses, potential improvements, etc., and the other half trying to enjoy the music. How, with the "Diapason," I am able to concentrate on the music only. What small imperfections exist are insignificant compared to the magnitude of its achievement. The "Diapason" is simply in a class by itself, and stands apart from previous and present designs in its ability to present the total impact of orchestra, chorus and organ as never before! ("Quite an ego, this Shahinian," you're thinking at this point....You listen and decide if it's not true.) With distortion at a vanishing point, frequency response and dynamic range at an awesome level, all requirements have been met. ..well, not quite. (We tried very hard, again, to make the "Diapason" invisible...and failed.) You may, of course,  listen in the dark, which actually improves illusion and perception.

   What makes the "Diapason" unique? To begin with, topography and layout. The upper module, which is dimensioned (22 "W x 15 ¾ "D x 7 "H) to fit precisely atop the "Double Eagle" subwoofer, is an asymmetric prism with unequal rakes, fore and aft; and equal rakes, left and right. The entire outer skin of this prism contains 14 separate loudspeakers, from 5 ¼” miniwoofers all the way to ⅜” supertweeter domes. The electrical distribution is a four-stage branch circuit of first and third order filters, resulting in a phase correct, seamless transition from about 125 Hz to 22,000 Hz. The word "seamless" has been grossly overused and requires, I believe, clarification, as regards a loudspeaker specifically. We know it means without breaks, seams. But that implies "perfect," which is impossible. This is, believe me, another of those dense complications one could explore to exhaustion. There are many accepted loudspeakers that fail woefully when each driver is examined at close range (near field) or all combined in the far field (3 meters or more). Almost fanatic attention was devoted to the character of each of the four stages in the "Diapason" module, and to their potential harmonious affinity. The inspiration came from music rather than a textbook; at the very end of Walton's Hindemith Variations (Columbia USA MS 6736) there is a ravishing passage consisting of a high pedal on violins, leading to a full brass chord, leading to a full woodwind chord, leading to a full string chord; seamless, absolutely seamless, as each group hands off to the other. The wizardry here, of Szell and the Cleveland Orchestra, has always stunned me and caused me to ponder if anyone could make a loudspeaker do the same thing. I believe we have. A solo speaking or singing voice is also difficult to project as a whole, a unity. This, the "Diapason" does handily. We've chosen appropriate, natural geometry, and we get the reward of exquisite results. It's one thing to use a megaphone outdoors, or aim a horn-type loudspeaker to get the attention of people, where there is an absence of a room or hall to collect and reinforce sound. It's quite another to bring one's mega-phone into a parlor, to speak with friends. And yet, almost all loudspeakers possess this "megaphone" effect, which is unacceptable. The entire skin of the "Diapason" module radiates energy outward, like a spherical, radial point source... ideal for the purpose ... like the mouth on your face. You don't have a horn on your mouth, do you? We don't on the "Diapason" either! And the governing principle is the same.

   Are we privy to secret data, or clues? No! It's one thing for Rice & Kellogg to have put a loudspeaker in a simple box in 1931, but just foolish in 2000! The theories are fundamental and common knowledge, conveniently ignored. (There's a huge profit in selling common box speakers. A careful scrutiny of a very famous $5,900-per-pair imported loudspeaker indicates that you pay almost $5,000 for the cabinets and crossovers. The published replacement cost of woofer, midrange and tweeter is about $600 per box! If we used a similar factor, the "Diapason" would sell for over $20,000! A small message here, perhaps?)

   Well, enough rhetoric, back to nuts and bolts. The "Diapason" module atop the "Double Eagle" becomes, the "Diapason" system. Though the "Diapason" might have been used with other subwoofers, none we or others have tested seem to do complete justice to the totality of the original design. There are, however, several usage permutations embodied and included at no extra charge. It is possible to choose, for peculiar environments, a crossover one octave higher than the basic 140 Hz by means of rewiring external terminals. It is also possible to overcome some spaciousness, if a more direct presentation is desired, by rotating the module 180°, facing the short angle forward. The

"Diapason" module may also be wall-mounted, at some distance from the subwoofer, if required. Primary filters may be bypassed for electronic crossover, bi-amp function. Other variations include bi-wiring and twin amplification (separate amplifiers for tops and woofers, passive filters), and additional surround subwoofers. Some unique high-power auditorium applications may be accomplished by simple stacking/multiplying.

   Words and words and more words, and we still haven't told you what a "Diapason" sounds like. Just as a great chef cannot tell you how his feast is going to taste, the only way to experience it is for yourself. The peculiar personality and character of the "Diapason" can only be hinted at. Do we mean to tell you the "Diapason" is not that paragon of virtues—neutral? Yes! Just as Heifetz's Stradivarius and Guameri had different personalities. (And we don't think it images well, either, whatever that means. As hard as we've tried, we can't seem to see anyone between our loudspeakers, whether playing or not.)

   My own reaction to all of this is rather unexpected. I had never anticipated quite the level, the standard achieved. I feel like saying, as Mozart did about his "Marriage of Figaro" in "Amadeus," "It's the best opera ever written"!

   The "Diapason" is absolutely the…well, I'll leave that to someone else. (I'm certain it's the best Armenian loudspeaker ever made, anyway.)

   It's here ...a real-world, cost-effective instrument you can acquire in stages or all at once. And crystallizes for sure that this is the best time in history for music lovers. As concert and opera tickets continue to climb beyond the workingman's reach, there's a pragmatic alternative at last—to assemble a system around such a speaker and have at your disposal the treasures of music on command. And for those of you, who feel the live concert experience can never be matched, relax; so do we. At times, it can actually be improved upon. (Imagine walking up, tapping the conductor on the shoulder and asking him to play Delius instead of Brahms…fat chance.)

   Listening to a pair of "Diapasons," coupled to a reasonable high-power system, can be a unique, new, awesome experience, likened only to a live concert. Of course, it is still artificial, synthetic; but you won't care anymore. The level of your involvement and concentration will exceed all previous experience. I know whereof I speak; this is not mere propaganda, talk for money. This is an artistic, cultural activity we hope many of you will share.

   About the press and propaganda: We've always felt it was a duty for any publication to report and print the news without partiality. To ignore facts or fabricate, as some have done, is odious. Small companies who may have much to offer the public may also be without the means to inform and promote. While I've thought we were doing that which was exciting and newsworthy, it seems I have been perceived as a musical genius and an audio eccentric. (So much easier to bury in fine print on page 5.... What? There is no page 5? Oh well, forget it!)

   You may imagine, then, my amazement at "colliding" with that elfin wordsmith, J. Gordon Holt, a man who loves, digests and writes about music. Yes, music! Over the years I may have ignored his work as much as he overlooked mine, but considered it essential to acquire any recording he mentioned in print. Well, the very unlikely has happened: We have befriended one another. Imagine, a journalist and crazy me! In the April 1990 issue of Stereophile, he has embarrassed me with an omnibus article on me, the "Diapason," audiophiles, music, philosophy, etc. I am grateful for his kindness and perceptive observations, but more than anything for a most magical evening in our exhibit room at winter C.E.S., where we (and a few others) spent about three hours listening to music including the whole of Copland's 3rd symphony (Levi, Atlanta, Telarc), ending with applause.

   For a brief time, we were transported to Symphony Hall Atlanta. It happened ...I was there. See you soon, Gordon.          



Double Eagle Stereo Subwoofer

Twin, back-to-back, hybrid transmission line/passive radiator bass chamber design with two 8” polypropylene curvilinear cone drivers. Features woofers with 1 ½” high-temperature patented D.D. voice coils and34-oz. Ceramic magnets; ¾” Finland Birch cabinet construction; built in 140 Hz/280 Hz 18 dB passive filters which may be bypassed for bi-amp operation; bridgeable into mono mode for double unit operation or stacked for quadruple high-power function. 5-way binding posts. Sits on 4 twin-wheel casters. 3-position passive input filter module optional. May be purchased separately from Diapason module.

Power handling: 300W max

Frequency Response: -3dB/23-140 Hz

Nominal Impedance: 6 ohms.

Sensitivity: 86 dB

Dimensions: 23” x 15” x 32”

Finish: Oak, Walnut, Cherry, or Rosewood

Weight: 105 lbs.

Diapason Module

Four 5 ¼” curved poly cone low/midrange drivers, two 1 ½” Titanium dome high midrange drivers, two 3” cambric dome low tweeters, and six ½” W-shaped Titanium dome supertweeters. Designed to fit precisely atop the Double Eagle subwoofer. Features cabinet constructed of 13-ply Finland Birch, and shaped as an asymmetric prism with unequal rakes fore and aft, and equal rakes left and right; also wall-mountable at some distance from subwoofer; low midrange drivers have 1-in voice coil and 20-oz ceramic magnet, high midranges have special east/west magnet structure, and low tweeters have phase correcting faceplate; electrical distribution is four stage branch circuit of first and third order filters for minimum phase function; 2 optional input filter choices, or direct bypass for electronic crossover and biamp function; other variations include biwiring and twin amplification; internal wiring consists of Kimber 4tc with low flux pure solder.

Power handling: 800W max

Frequency Response: -3dB/125-22,000 Hz

Nominal Impedance: 6 ohms.

Dimensions: 22” x 7” x 15 ¾”

Sensitivity: 89 dB

Weight: 33 lbs.