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VR-4

Virtual Pleasure
     Hi Fi & Musik has for a long time been looking for a reference speaker system. Finally, we think that we have found it, and to our amusement, it is related to one of H&M’s very first reference speakers, the legendary Dahlquist DQ-10.

     A sensation of absolute bliss has reigned over the editorial office lately. Never before has so much music been played during office hours and never before have so many of the editorial staff remained sitting in the listening room. The reason for this is, as you might have noticed in the summer issue of Hi Fi & Musik; the VR-4 speakers, designed by Albert Von Schweikert. No, this is not a student prank. This is his real name and his words now carry great weight at the editorial office. His and Stig Carlsson’s... of course.

     Albert Von Schweikert was born in Germany but moved to the USA at an early age. From a young age he has been into audio and during his years in college he worked with acoustic and speaker technology at Cal Tech, under the legendary Dr. Richard Heyser. At that point in time Heyser was busy developing his revolutionary Time Delay Spectrometry, which made it possible to measure the frequency very precisely, without the need for an echo free room. This test’s so called "waterfall measurement" would not be possible without Heyser’s research.

     In spite of the fact that Von Schweikert has been a anonymous public figure, reading the list of companies which have turned to or are still turning to him for consulting is like reading the Who’s Who of American High-end audio. Names such as JBL, Agopee, NHT, Bose and Lucas Films ( THX™ ) appear. One of his most spectacular creations is his Plasma Speakers (!) from the seventies called The Forcefield and the monstrous Armageddon with a weight of 900 kg, which have a frequency range down to 10 Hz and a price tag of 59,000 dollars! Armageddon became a veritable blockbuster during the show in Chicago 1993. Von Schweikert has also recently developed an advanced and awarded THX-system for Counterpoint.

Virtual Reality
     So far the man. Nowadays he has his own company, and the first model of speakers we have the pleasure of listening to are the VR-4’s. We chuckled when we realized that VR is supposed to stand for Virtual Reality, but our scornful smiles were soon changed into an amazed silence. But more about that later.

     VR-4 is crammed with patented masterstrokes and it is something as confusing as a 4-way speaker which is acting as a 1-way point source. Partly bipolar in addition, with a tweeter turned backwards.

     So how does this all add up then? Well, you see, Von Schweikert has had some very clear objectives in mind and of these first and foremost to merge a powerful full range construction, with the homogeneity and point dispersion quality of an airy, baffle-free, 1-way design. This virtually baffle-free construction, in combination with the backward dispersion over 1 kHz for an optimal scope sound, has made the VR-4 a speaker which dispersion and wide open stereo scenery is beyond all description.

     Irrespective of the size of the room and irrespective of were you are sitting - or standing up - you will experience an ultra-precise and shocking three dimensional stereo accuracy. In this regard the VR-4 resembles the German MBL round radiant speakers quite much. Because just like the costly German speakers the stereo scenery follows you in all height, width and depth dimensions wherever you happen to be in the room. Clear as a bell and steady as a rock.

     An eerie feeling, I assure you, and if you, ( like me ) should be interested in getting the illusion of actually listening to physically present musicians whom are playing in one highly apparent recording studio, then you will really get your money’s worth ( and even more! ) from Von Schweikert’s construction.

     It was precisely the airiness and the spaciousness ( particularly of the bass! ) that over and over reminded me of another heavyweight champ in this field, Stig Carlsson’s little piece of magic the OA-52. 2:s. Because in spite of the fundamental differences in the construction they are both members of the same faith. They both strive for an extreme point configuration and for the dispersion tone to be identical with the direct tone. The loudspeaker designers usually don’t think too highly of their peers, but Albert would definitely have liked the OA- 52.2´s.

No Distortion
     Just after a short while of listening, one realizes that Von Schweikert puts distortion combating high on his list. In spite of its physical size and complexity the VR-4 is an amazingly resonance-dead and transparent speaker, even at very high volume levels. One of the reasons is, of course, that the section for the upper register lacks a baffle ( just like the old DQ-10 ), but another reason is that it is resting on a floating suspension on the very stable lower part of the base. The upper part is placed on small dampers that easily, but effectively, uncouple the upper part free of the lower part of the base.

     The intricate stapling of the lower part and the floating upper part makes the sound from the speakers transparent and totally clear. A strange feeling since the VR-4 without trouble can send vibrating shock waves of precipitous "body-bass" through the listening room. Everything else may have been shaking but the speakers remained standing firmly as sandbags.

     But it is not just the construction that has contributed to the coherent sound; the included drivers of the speakers mean at least as much. Here the custom made 5.25" carbon fiber midrange Audax-driver with edge placed coil wire, made of aluminum, is what plays the leading part. The element is developed to handle frequencies from around 60 Hz to 12 kHz so it easily handles its working range of 125Hz to 3,5 kHz. A large part of the VR- 4 character is shaped of this element which is installed in a long, closed rectangular box which patented sound labyrinth almost completely absorbs the element’s backward radiation.

     Above the Audax driver is a 1" custom made aluminum dome ( Vifa ) which is complemented with a 1" driver at the back edge of the speaker. The latter starts at levels over 1 kHz and it’s possible to cut it out completely, but we got the best result with the full level of the backwards dispersion. The sound becomes a bit wider still and with an airy character and a magnificent panorama. Furthermore, the relief effect of the stereo perspective became even more clear-cut.

     Two 8" extended throw designed polypropylene/epoxy hybrids with a coil in four layers makes up the woofer. The driver has got superior bass reflex chambers with different tuning and low pass filtering (60 Hz and 125Hz). The latter is to prevent the bass from thickening in the sound spectrum. Rarely words such as authority and control have been so adequate as here, and one could easily believe that the VR-4’s bass was equipped with active power steering.

     I have myself become rather spoiled by deep bass, with the servo-controlled Genesis subwoofer, that I bought a couple of years ago, but with the VR-4 I never missed it. Bass capacity speakers have a tendency to give a stunning pressure chamber feeling in the listening room, but the VR-4 always delivered a powerful and at the same time, irrespective of the size of the room, quick dynamic bass.

The Patented Filter
     But now we are forgetting a very important part of the speaker, namely the crossover. The filter has been given a high priority and many of the pending patents are about the filter. The reason for this is that Von Schweikert, in spite of all the speaker drivers, did not want to forego the homogeneity of the sound. In reality the speaker has 24dB of crossover cutting, but in spite of that it has got a very straight frequency curve and phase response over a very wide dispersion area ( over 90 degrees horizontally, 70 degrees vertically ).

     Considerable brain work has thus been put into the filter, since the advantages steep filters offer ( measured in front of a speaker ) effectively used to be sabotaged by all the phase and frequency disturbances the filters produce at the side dispersion. Therefore we had the feeling that the GAIN-filter would be a real gourmet dish even before we had read about the background.

     GAIN stands for Global Axis Integration Network and it is a patented crossover construction which is meant to produce as homogenous and phase correct a sound as possible. In spite of the obvious complexity, the number of components has been reduced to 14, of which the greater part are not placed in sequence with the signals but go to earth. The bass and treble sections’ filters are completely separated and the VR-4 is meant to be driven by separate amplifier cables, alternatively even using separate amplifiers for each section.

     We tried all thinkable combinations but H&M´s own chaos pilot Olle Linder lifted the VR-4 to dizzying heights with an audiophile special preparation: 18 triode watt in the upper section - Audion Silver Night - and a 200 Watt solid state in the bottom - Rotel RHB-10. But the VR-4 sounded brilliantly lively with the summer issue’s amplifier, Pass Aleph 3, on 30W, and it is a matter of fact that very few speakers have been so amplifier tolerant as the VR-4.

The Most Complete Speaker on the Market
     After having listened to the VR-4 together with various auxiliary equipment and in various rooms we have become more and more convinced that this must be one of the most comprehensive and most complete speakers on the market. It has not disappointed us on one single point. Even the "bass nuts" at our sister publication, The Car Stereo Magazine, were happy with it. That does not happen too often!

     It almost feels as if we have done an audiophile scoop on our own, because to our surprise we have only seen one previous test of these speakers and that was in the American underground magazine "Positive Feedback." Perhaps the reason for this is that the VR-4 is not expensive enough for the major High-End magazines to take notice of it. But soon they will have to do that, because the VR-4 will pull the pants off hordes of more expensive competitors. It is exactly what Albert seems to have had in mind - to prove that real audiophile sound does not have to cost a year’s earnings. And on top of that you can even dance to it!

Von Schweikert or Wilson?
     A last observation. The day before the VR-4 was hauled into our office, I had had a long and exhilarating listening evening with some friends. We had been listening to Wilson’s Watt/Puppy System 5 with tube electronic and an SME 20/Ortofon Mc7500 analogue combo. I was deeply touched by these precision tools and on my way home I played with the thought of buying myself a pair. ( I said, played with the thought! )

     The ultra sophisticated Wilson will always tempt me, but not even the Watt made me reach all the way to the ceiling as the powerful VR-4 did when they began playing at the office the next day.

     My most sincere recommendation, without a doubt !

Conclusions
     An amazingly ingenious loudspeaker with a magnificent sound dispersion and an exact 3:D reproduction. One is truly overwhelmed by the mighty sense of presence. The VR-4 does not seem to lack anything, and it goes directly to the top of HiFi & Musik’s hit parade.

HiFi & Musik
September 1996

Graphs from the Article

CUMULATIVE SPECTRAL DECAY PLOT:

The commonly known "waterfall" ( or Cumulative Spectral Decay Plot ) displays a single impulse reproduced by the speaker ( VR-4 ) which is allowed to decay naturally. Each of the succeeding responses have been taken as "snapshots" in frequency versus time as the speaker "settles" from the original impulse. Two main characteristics can be learned from this plot. First, the overall flatness of the curve shows that the speaker has linear frequency response, without significant dips or peaks. Very few speakers in the world have response this accurate. Second, the original impulse is seen to decay quite rapidly, without any major resonances being evident. This indicates that the speaker ( VR-4 ) has excellent drivers, crossover circuits, and cabinet damping, in turn permitting very clear sound reproduction without coloration. This measurement is truly world class, indicating that the VR-4 is one of the best engineered speakers in the world.

IMPEDANCE CURVE:

This measurement shows the speaker's impedance in ohms versus frequency. It is useful to predict how an amplifier will interact with the speaker inquestion, a VR-4. The most important factor to consider is a low impedance "dip" which might allow an amplifier to go into distortion if it does not have a "high current" power supply. The VR-4 has a low of 3.8 ohms at 25Hz, caused by the bass tuning, which is in the range of almost any amplifier to drive, especially since the phase of the slope is not very reactive. The twin peaks at approximately 2kHz show the tweeter's crossover impedance, and at 19 ohms, is not a problem for any amplifier. This peak is caused by the resistance added to the tweeter to equalize it to the midrange driver's sensitivity. This should not be confused with frequency response peaks, as it does not indicate a peak in the sound pressure. Overall, this impedance curve is about average, and indicates a speaker which almost any amplifier can drive.