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System of the Month
Von Schweikert Research You can be certain that many an audio product had its roots in someone's garage, from the first Edison wax cylinder players to the amplifier you may be listening to at present. Many designers of audio equipment do in fact start out there, experimenting for years to tweak their ideas into perfection, then producing products on a limited-run basis until a buzz gets out and their garage project sprouts into an institution. Such is the case with Von Schweikert Research. The designer of the Virtual Reality Series, Albert Von Schweikert, has been working out his theories of loudspeaker design for decades, implementing them in a series of statement products called the VR line. Other notable Von Schweikert endeavors have included serving as a consultant and designer of THX speaker systems for various companies. We've had a passing familiarity with Von Schweikert's work for some time now, but it wasn't until the introduction of the Virtual Reality Theater series, which he specifically designed to address the needs of the home theater market, that we really had a chance to check out what was going on over a Von Schweikert Research. The Virtual Reality Theater line comprises three different systems. Of these, we received their mid priced offering, consisting of the VR-2000 tower speakers, the LCR-20 center speaker and the TS-200 surround speakers. Although their VR-2000 based system is adequately full-range, with bass extension specified at 24 Hz; the company also provided us with their recently designed powered sub. The Tower of Power subwoofer, which features a Bob Carver-designed amplifier, had just been released in working prototype form by the time we finished looking at the system; it's a serious contender in the powered subwoofer category, so anticipate a full review in an upcoming issue of Home Theater. True to the spirit of garage culture, Von Schweikert Research speakers undergo a rigorous burn-in period with a truly nasty sounding Dick Dale recording. The designer feels this methodology works better than plain old pink noise. So, with a few hours of the King of the Surf Guitar’s work imprinted onto the system upon un-boxing, we were ready to listen. With their narrow profile, and a shrouded-in-black-fabric appearance, the VR-2000 towers have a strikingly similar look to some to the better known bipolar speakers on the market, some of which have previously appeared in the pages of Home Theater. But the similarities cease on a cosmetic level; Von Schweikert's approach to crossover design is unique, making the VR-2000 an entirely different creature under the hood. The 5.5-inch midrange driver is made from woven carbon fiber, an exotic material exhibiting a high stiffness-to-mass ratio that can be found in, among other things, certain high-end phono cartridges and tonearms. A 1-inch aluminum dome tweeter handles high frequencies; a 10-inch woofer mounted on the side of the cabinet handles the lows. Part of what makes the VR-2000 unique is an ambience driver mounted onto the rear of the cabinet that emits an out-of-phase, time-delayed derivation of the midrange/treble information. Von Schweikert feels that conventional direct-radiating speakers fall short in replication the actual acoustic space in which live music is recorded; thus, all of his speaker designs attempt to replicate the 360-degree pattern in which sound naturally emanates and is picked up by an omnidirectional microphone. According to Von Schweikert, the ambience driver on the rear decodes a 360-degree soundfield that is the direct inverse of the signal encoded by the microphone. The designer says this provides a fuller, more natural presentation that's devoid of the beaming effects that plague point-source speakers. A level pot on the back of the VR-2000 allows for control of the ambience driver's output, enabling the listener to tailor it to taste or defeat it altogether. Like other Von Schweikert speakers, the VR-2000 is a phase-coherent design. In most instances, phase coherent means it use a first-order crossover network to filter the signal, passing bass, treble, and midrange information to the appropriate drivers. First-order crossovers have the benefit of maintaining consistent phase throughout the frequency spectrum; second-order crossovers, in contrast, shift the phase of the drivers by 90 degrees. The drawback of using a first-order crossover is that the crossover slopes are relatively shallow - 6 dB per octave, as compared to the 12 dB/octave of a second-order filter. Thus, when a speaker uses a first-order crossover, more low frequency information passes into the midrange driver and tweeter. This affects sound clarity, particularly when you push the speaker to loud levels. Von Schweikert Research speakers, however, are unlike other phase-coherent designs in that the crossover networks have extremely steep slopes -- somewhere around 24 dB/octave -- while maintaining phase consistency between the drivers. The technique Von Schweikert developed to accomplish this feat is called the Global Axis Integration Network. The actual engineering involved would take more space to explain than I have room for. But basically Von Schweikert says GAIN eliminates colorations and distortion caused by driver overlap, and creates a very wide dispersion pattern that maintains correct phase, which means your head isn't locked into a narrow "sweet spot." The LCR-20 center speaker features two of the same 5.5-inch carbon fiber mid-drivers found in the VR-2000s, as well as the same 1-inch aluminum dome tweeter. A vent on the back serves Vocal Presence control pot on the side boosts or cuts frequencies between 1 and 10 kHz by plus or minus 3 dB. According to Von Schweikert, the effect of the Vocal Presence control is to push dialogue back when it's mixed too forward on a soundtrack, or bring it forward in a situation where dialogue intelligibility is handicapped. For our testing, we left this control on the flat setting at all times. Von Schweikert's wall mountable TS-200 surround speakers feature a toggle button that allows the listener to switch between dipolar array for listening to Dolby Pro Logic-processed material, and a direct-radiator for discrete 5.1-channel sources (which the designer insists is more appropriate). The front baffle of the TS-200 features a 5.5-inch carbon-fiber midrange driver and a 1-inch aluminum dome tweeter, while the angled side baffles feature 4-inch coaxial mid-treble drivers wired in a dipolar configuration. When you press the button, the side drivers become inactive, making the TS-200 work as a direct-radiator. Listening to the system showed that Von Schweikert's design goals had been met. Vocal intelligibility was as good as I've heard on any system, rendering dialogue in an extremely clear and detailed manner. Since I was reviewing DVD players at the same time, most of the software I used were DVDs with Dolby Digital soundtracks, which meant I left the TS-200 surround speakers at the direct-radiator setting. Whatever the shortcomings as a work of cinematic art, the Twister soundtrack offers some really incredible discrete surround effects that will give your surround speakers a heavy workout. With bass extension specified at 60 Hz, the TS-200s were more than ready for Twister, effortlessly reproducing the swirling wind tunnels, and providing seamless transitions on front-to-back effect pans. One listen to the VR-2000 towers and you'll know exactly how they deviate from standard phase-coherent designs. These speakers were incredibly dynamic on both music and movie sources, and could be pushed to dramatically loud volume levels without sounding thin or shrill. All in all, the VR-2000-based system was very impressive when reproducing movie soundtracks, providing a sense of complete enclosure within a 360-degree soundfield, which really drew us into the onscreen action. On stereo music recordings, the VR-2000s manage to pull of a trick that very few other speakers are capable of, which is to provide accurate imaging over a large area. Most speakers nail your head into a single sweet spot where the music comes to life. This three-dimensional effect will flatten considerably the moment you move your head off axis, which is the main reason why listening to stereo has always been a solitary pursuit. The VR-2000s maintain an accurate soundstage over a relatively large arc, meaning that more than one person can have an involving experience.
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Our first pair of VR-2000s were prototypes, which extensive music-listening sessions revealed to have some shortcomings. The proto pair's treble had an inescapably forward quality, while the bass was boomy and ill defined. A second pair of VR-2000s (apparently pulled of the production line), however, sounded dramatically better, with a very natural tonal balance throughout the mids and highs, and solid, low reaching bass. While we're on the subject of bass, achieving good bass performance with the VR-2000s requires a bit of an effort: The speakers have been designed to be placed near the rear wall of a listening room. Anchoring them too far out into a room will generally result in weak bass, while placing them too close to the wall or corners will result in flabby, booming bass. Our advice: Patiently walk your VR-2000s around, always remaining within 1.5 to 2 feet from the rear wall, and you'll eventually key in on the spot where the bass will sound best. The Von Schweikert Virtual Reality Theater is perhaps the most flexible system we've ever seen, providing a host of options that will allow you to tailor the system to your listening room. Setting up the VR-2000 towers does require a concentrated effort to achieve optimal bass performance, but once you have it, you can settle back for some high-octane home theater. |
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By: Al Griffin |
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