AEMPYREAN BASED OUT OF SACRAMENTO-CALIFORNIA USA
A NEW BRAND IS BORN
AEMPYREAN is the AE or Ligature spelling of the Medieval Latin word EMPYREAN meaning the realm of fire in the Highest Heaven, inhabited with beings of pure light. The original source word is from ancient Greek, with much the same meaning. Likely the best known appearance of the word is in the DIVINE COMEDY, first made public in about 1321.
Both words contain the concept of pure ideality or intelligence, which implied meaning governed our original interest in naming a quest for audio fidelity ideality AEMPYREAN. We were in the process then of beginning the manufacturing of ultra-high performance fiber composite planar transducers for application on the room boundary pressure zone walls.
Earlier granted OS and European patents had shown a full range AMT type transduction system, which we planned to iterate on into high-end production in Germany.
The first product in the AEMPYREAN series in the TEMPEST ONE, which is a tapered transmission line design intended for mounting on a sturdy stand adjacent to the wall or on the room boundary wall itself.
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DESIGN FOUNDATION OF THE TEMPEST ONE TRANSMISSION LINE SYSTEM
The TEMPEST ONE is a combined line source, planar source design, with the added advantage of optimum operation securely mounted to a room boundary wall, or on designer stands allowing transducer operation immediately adjacent to the pressure zone room boundary. Acoustical operation in the pressure zone confers many sound field benefits, as the wall represents simply an extension of the speaker baffle board itself, directing all radiated sound power directly forward in the listening space.
Thus the entire output of the TEMPEST ONE radiates into a hemisphere of free space: a half space or 2pi sound field, rather than into a partial sphere as would a free-standing, in room, direct radiator speaker system.
Because the listening space is a half-space, or hemisphere at all frequencies, especially in the bass, where the sound field is truly omni-directional, the radiated sound power is slowly elevated by rising first order room gain, yielding full non-resonant bass power radiation free from transducer resonance at a sharp combined driver enclosure Q factor.
In a multiple driver line source array, the effective radiating driver surface area is large, and planar, the TEMPEST ONE does not follow the inverse square law diminution of sound intensity law typical of small compression drivers, but is rather governed by rate of attenuation of 3 dB for each doubling of distance from the transducer source.
The TEMPEST ONE is an electromagnetically driven quarter wave, first order transmission line system, and exhibits nearly perfect well damped resistive behavior: it is neither inductive or capacitive, as either condition places current and voltage waveforms out of phase with each other.
As a linear, first order, resistive transducer system the TEMPEST ONE is a natural, supremely NEUTRAL voice to the most complex and demanding musical waveforms.
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THE SURPRISING ANTIQUITY OF THE AIR MOTION TRANSFORMER SPEAKER DESIGN PRINCIPLE OF THE AEMPYREAN REFERENCE ONE
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Most audiophiles associate the AIR MOTION TRANSFORMER loudspeaker design with ELECTROSTATIC SOUND SYSTEMS, INC, known as ESS. As I write this discussion I’m referencing the much distributed eight page color brochure from around 1973, which discusses the operational details of the transducer, and lists the product range available then: beginning with the now collectable AMT-1, on through the AMT TOWER, the AMT 3 ROCK MONITOR, the AMT 4 and 5, on to the AMT 6 PROFESSIONAL. Over the production years, until ESS was sold, many other model iterations evolved also.
The sonic performance of the AMT line is well described by the advertising phrase, SOUND AS CLEAR AS LIGHT. In the product line, the AMT 1 TOWER with an Arthur Bailey type transmission line, hearkens back to my design of the TRANS-STATIC I, which was the first ESS product.
Now within inventive reality, the ESS AIR MOTION TRANSFORMER as created by Oskar Heil, and patented by him several times in the Seventies, was not quite the unexampled first revelation of the design principle ever, a unique in all the world device, as then often believed.
For the actual history of the AIR MOTION TRANSFORMER principle, basically inhaling and exhaling, while accelerating, or TRANSFORMING the direction and velocity, of a partially confined volume of air; we turn to a superlative and exhaustive text by Justus Verhagen, PhD: RIBBON LOUDSPEAKERS THEORY AND CONSTRUCTION. ISBN Number 1-882580-24-X. The Heil AMT design is a subset of ribbon transducers generally: or more specifically folded ribbon transducers in general. The book referenced above carefully and thoroughly explicates the early days of ribbon transducer development in Germany in the period
just subsequent to the First World War. This well written and well-documented section reveals a surprising progenitor of the AIR MOTION TRANSFORMER: the patented Erwin Gerlach ZIG-ZAG TRANSDUCER, discussed and described in 1924. This transducer meets all of the AMT criteria stated above with respect to transforming the direction and velocity of a partially confined volume of air. Now historical detail minded people will recall that eventually the mid and high frequency response of the ESS AMT was extended on down in frequency in an iteration named the TRANSAR, carefully described in patent detail, but largely unsuccessful,
perhaps because of excessive complexity. However, much truly excellent patent research and product development has followed the Oskar Heil ESS work, so that now extremely high -quality AMT mid-high drivers are quite reasonable in price.
Thus far the Gerlach-Heil AMT principle has not produced a successful full range loudspeaker system, although the related thin film planar magnetic and electrostatics technologies certainly have: these speakers are among the very best in the world.
We have a patented, extended deep bass, in fact, capable to pulsed DC AMT technology as embodied, and described in granted US Patent 5,872,853. We’re working now on building a full range AIR MOTION TRANSFORMER transducer system, which should fully establish the Gerlach-Heil principles as capable of the absolute highest full range and beyond musical fidelity.