MicrophoneEngineered to perform like a Microphone in Reverse

Von Schweikert

Research

 

 

BLANK.GIF (812 bytes)VR Home
BLANK.GIF (812 bytes)bluearrow.gif (102 bytes) History of VR
BLANK.GIF (812 bytes)bluearrow.gif (102 bytes) Design Theory
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BLANK.GIF (812 bytes)VR Line
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BLANK.GIF (812 bytes)bluearrow.gif (102 bytes) VR-8
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BLANK.GIF (812 bytes)VR Theater
BLANK.GIF (812 bytes)bluearrow.gif (102 bytes) VR-1100
BLANK.GIF (812 bytes)bluearrow.gif (102 bytes) VR-2100
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BLANK.GIF (812 bytes)bluearrow.gif (102 bytes) TS-110
BLANK.GIF (812 bytes)bluearrow.gif (102 bytes) TS-210
BLANK.GIF (812 bytes)bluearrow.gif (102 bytes) TS-310
BLANK.GIF (812 bytes)bluearrow.gif (102 bytes) Subwoofer
BLANK.GIF (812 bytes)VR MiniMonitor
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BLANK.GIF (812 bytes)bluearrow.gif (102 bytes)VM-3
BLANK.GIF (812 bytes)The Reviews
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BLANK.GIF (812 bytes)Contact Us

The Von Schweikert Research VR-8.

Albert Von Schweikert is proud to present the Virtual Reality VR-8 to those wishing to experience music on an exalted level, far beyond ordinary expectations, without compromise.

Do you remember the moment you fell in love with audio? For many of us, emotional involvement with music and quality sound reproduction is a profound experience. If you love music as much as I, you will understand why I have spent over twenty years developing my concept of Virtual Reality which has led to the VR-8. Along the way, I have discovered technology which allows a more faithful recreation of a sonic illusion. Acoustic Inverse Replication enables the speaker to "decode" the spatial sound field picked up at the recording site. In effect, the speaker behaves as a mic in reverse, allowing the original perspective to be reproduced in your home. The Global Axis Integration Network is a circuit I've developed which allows the VR-8 to radiate sound waves in a spherical pattern without beaming, similar to live instruments. This, along with A.I.R., enables soundstage imaging over a broader area of the room and replicates the psychoacoustic cues necessary for Virtual Reality. This crossover circuit along with a specialized driver radiation pattern using front and rear driver arrays, combine to enable true room filling sound with breath taking 3-D imaging.

Frequency, phase and transient response, including low distortion and coloration, have seemingly been perfected in modern loudspeaker design. Yet "realism", the missing ingredient, has eluded even the most ambitious and expensive systems. Initially, I thought that extreme clarity would provide this ingredient, and exotic drivers were utilized with lighter, stiffer diaphragms made from woven carbon fiber and titanium. However, although enhanced clarity did provide a better "window" to the performance, it alone did not provide this missing element.

Several years ago I became interested in developing a speaker system of high efficiency suitable for use with low powered amplifiers and "rediscovered" the effects of high dynamic range. As the magnet strength was increased and the diaphragms lightened further, the drivers sounded more "alive" due to the actual clarity increase combined with the effects of increased dynamics. Minute details veiled by low and medium efficiency transducers were brought out in full relief. The heightened dynamic range also resulted in a very high excitement factor.

However, when combining several drivers which seemed to have promise, I discovered that the enclosure and crossover circuitry had to be developed in parallel with the transducers, not as an afterthought. The dissipation of low level detail by enclosure vibration and circuit absorption had a very deleterious effect on realism.

I have termed this dissipation of low level signal information "The Masking Effect", and the resulting design of the VR-8 seeks to achieve the missing realism by eliminating low level dissipation.

A significant portion of the drivers energy is absorbed, hence destroyed, by the medium-mass enclosures of typical high end construction, since the moving diaphragm can either convert the energy of the electrical signal into sound waves or cabinet vibration. Dramatically increasing the enclosures mass has the effect of providing a non movable foundation which in turn allows very subtle diaphragm motions to be heard. The increase in low level detail add a "breathiness" which I found very captivating and high in the realism quotient.

Next, I did research on typical crossover circuit components and found that normally accepted dissipation in even expensive film capacitors and air cored inductors was absorbing far too much low level detail. Several months were spent testing all available capacitor types, including the most expensive aerospace units not generally available. Amazingly, the best performing units were "ancient" can-type oil filled paper units, dating back to the beginnings of radio. Not surprisingly, these are the same type of caps used in the $ 78,000 Audio Note Ongaku amplifier, generally accepted as a "milestone" product.

Further research into wire and inductors led to our design of a proprietary solid core wire, featuring extremely high purity and a foamed Teflon dielectric covering. The wire permits very low level detail to be easily heard, as the reactive effects of inductance, resistance, and capacitance are minimized.

In addition to the specially designed electrical components and wire, the actual circuit topology is of innovative design. My Acoustic Inverse Replication (AIR) radiation pattern is employed, since the goal of a true reference loudspeaker is to radiate the signal back into the room in the same manner as the microphone picked it up. In conjunction with the Global Axis Integration Network, my name for the special circuit, the AIR design allows a very wide dispersion pattern to develop. Listeners can sit virtually anywhere in the room and hear excellent stereophonic imaging, even when standing in between or behind the speakers.

The VR-8 system has been dubbed an "unlimited performance" system since every aspect of it’s design and construction has been engineered to provide the ultimate sense of realism. Musical information simply dissipated and lost in other systems comes alive. For instance, full bass response and wide sound stage imaging is available at whisper volume levels. The VR-8 has a sensitivity of 96DB, making it at least five times more efficient than most planar speakers. The efficiency gain is similar to increasing the amplifiers power from a few watts to hundreds of watts.

Since dynamic range is now heightened to very dramatic levels, low level detail is "magnified" and crescendos are rendered to very high volume levels with out a trace of distortion or strain. Frequency bandwidth has been extended at the same time, with an available response from 16Hz to 40Khz. Coloration has been reduced to imperceptible levels, as the driver technology is at the state-of-the-art level. Woven carbon fiber fabric is employed in the twin midrange drivers, where oxidized titanium is used for the tweeter diaphragms. Each enclosure weighs close to 500 lb. due to the use of critically braced MDF from 1" to 3" thick. Recommended power is from 7 watts up to one kilowatt. Impedance is 4 ohms with very little variation. The Midrange . Treble unit is adjustable for vertical angle and is Time aligned, providing the ultimate in depth and imaging.

VR-8 Specifications

Crossover frequencies: Virtual "one-way" design, using full range drivers as "main" system, augmented at sub-bass and treble frequencies. The frequencies chosen, 100Hz and 3.5Khz, are well outside the ear’s most sensitive range, allowing full midrange coherency without driver overlap.

Bass system: 13" sub-bass and 10" midbass high efficiency, cast frame drivers using extremely stiff and lightweight paper cones, large 4" voice coils, and huge 6000 gram magnets. Separate periodically vented enclosures are tuned to a sixth order Chebychev alignment which features transient response speed enhancement due to magnetic overdamping and 100% stuffing fill.

Midrange system: Twin 5.5" cast frame drivers, featuring woven carbon fiber diaphragms, edge wound ribbon voice coils, oversized vented magnets, and Norsorex surrounds. All 4 midrange drivers have tested and matched frequency response tolerances to within 1/4 dB.

Treble system: Titanium inverse dome with dioxide damping layer, phase control plate, transmission line loading, Ferrofluid cooling, and enormous 1200 gram magnetic structure.

Ambiance retrieval system: Rear firing midrange / treble driver ( same as front tweeter ) with Ambiance Derivation Circuit and Spatial Dimensional control for effects level.

Frequency response: 16 Hz ( with optional filter ) to 35Khz, +/- 3 DB. ( Midrange +/- 1 DB )

Inputs: Separate pairs of metal posts for woofer, midrange / treble inputs for bi-amping or bi-wiring.

Sensitivity: 96Db @ 1W 1M anechoic, 100 Db measured in room with boundary boost.

Impedance: Four ohms nominal rating. High current tube or solid state amplifiers recommended.

Power recommendations: Five watts minimum, 1000 watts maximum peak input.

Enclosure: Two piece stacking type, with wall thickness varying from 1" to 3" using constrained layer damping techniques and cross bracing. Adjustable midrange / treble module with time aligned drivers.

Weight: 500 lb. ea.

Dimensions 74" H X 18" W X 28" D.

Suggested Retail: starting at $17,500 per pair depending on finish selection

 


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