Von Schweikert Audio VR-55 Aktive Loudspeaker

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Von Schweikert Audio VR-55
Von Schweikert Audio VR-55 Aktive Loudspeaker

Developed to update and replace the aging VR-5 series of products first introduced in 2004, the new Von Schweikert Audio four-driver, three-way VR-55 is available in either a Passive or Aktive version. The Aktive is identical to the Passive, save for the addition of an on-board 525-watt mono amp to drive the twin custom woofers.

The VR-55’s enclosure generally follows the form factor initially seen in the original VR-5 head units, though that model’s two-piece stacking bass-module and mid/tweeter-module are now a single cabinet, like that of the VR-44 (the replacement for the longstanding and diverse VR-4 lineup). Standing 42" tall, 14" wide at the base, and 28" deep, tipping the scales at an impressive 190 pounds, the VR-55 Aktive employs a very narrow, chamfered front baffle around both the custom 6.5" ceramic midrange and the doped beryllium tweeter. The baffle shape is designed to promote wide dispersion. The front baffle slopes slightly backward, tapering from 14" wide at the base to just 9" wide at the top, to facilitate driver time alignment and accommodate the twin custom 8" woofers housed in the bottom of the baffle and the large Class D amplifier in the back.

Fabricated using VSA’s patent-pending Triple-Wall Laminate Construction, my review pair’s enclosures were finished in an impeccable piano-black lacquer. The outermost layer of this composite is a sheet of resin-based MDF (medium density fiberboard). The middle layer is a sheet of synthetic stone—made from crushed gravel, various other minerals, and a resin binder—that’s bonded to the inner surface of the MDF outer shell. The innermost layer is hard felt.

Each of these three incongruent layers is bonded to the next with a thick (roughly 1/5th of an inch), industrial, anti-vibrational, rubber-based adhesive designed to add yet an additional obstacle to vibration. The resultant triple-layered wall is roughly three inches thick. This construction exploits the natural effects of using three disparate layers, all with inherently different and effectively opposing native “Q’s,” working together as a resonance-cancellation system that effectively turns any unwanted energy into heat.

The finishing enclosure touch is what VSA calls Gradient Density Damping. This proprietary technique includes three different thicknesses of bonded Dacron batting. Packed extremely tightly closest to the cabinet walls, its density gradually decreases (i.e., it is less densely packed) as it nears the rear of the driver on its baffle. This innovative construction helps to provide exceptional absorption while greatly reducing reflections back into the cone.

First pioneered in the VSA UniField Model 3 speaker system in 2007, Gradient Density Damping is the result of extensive research using Cal Tech’s Laser Interferometer Lab to measure speaker cabinet-wall vibration and the internal mechanical processes of stored-and-released energy. According to Von Schweikert, cabinets constructed with this method offer measurably superior results to those using solid aluminum enclosures—and do so at a drastically lower cabinet-production cost. This approach has proven so successful that it is utilized in all VSA models in production today, from the Vortex VR-22, to the VR-11SE Mk2, and the one-off, statement, four-tower VR-111XS.

The rear panel is busier than most, and its contents contribute significantly to the VR-55 Aktive’s unique ability to seamlessly integrate with any room. Situated centrally on its nine-inch width—two inches down from the top—is the four-inch round housing for the 3" Rear Ambiance Retrieval ribbon tweeter, intended to match the transient response and tonal quality of the superb front tweeter and to help effectively replicate the concert hall (or recording studio’s) acoustic space. An all-new ambience-retrieval circuit with a level control is also included. This control allows owners to tailor the rear tweeter’s dipolar dispersion pattern and intensity to the environment—be it a hard and reflective surface or a softer, more absorptive one such as a curtain.

Behind a ten-inch-square silver plate near the bottom of speaker is a 525-watt mono Class D amplifier—engineered by and sourced from Channel Islands Audio, and using Hypex transistor modules and a linear power supply. This housing also contains the IEC socket and its amber-lit rocker-switch, two sets of five-way binding posts for bi-wiring, and two small, round control knobs for fine-tuning both the woofers and the rear tweeter. (More on this later.)

Both sets of binding posts are WBT-0710Cu Nextgen, fabricated from 99.996% pure, oxygen-free copper plated with a single layer of 24k gold and fully insulated with Makrolon. This copper/gold combination was chosen over similar posts fabricated from silver or platinum purely for its “sweeter” sonics.

About four inches above the amplifier plate, centered horizontally, is the six-inch mouth of the fluted woofer port. The woofer system employs a four-chamber hybrid transmission line and is user-adjustable via the rear-loaded port, with a factory preset “Q” of 0.6.

Moving to the front baffle, we find a unique driver set, the result of a four-year collaboration between Albert Von Schweikert and both Thiel and Partner (Accuton) and Scan-Speak. Albert’s desire to eliminate what he felt was an unnatural resonance that spot-lit certain frequencies and prevented an overall natural timbre eventually led to the development of the VR-55’s 8.5" and 6.5" Accuton ceramic-on-Nomex honeycomb drivers. Both employ what can only be described as massive, vanishingly low-distortion motors. (Yet none of this would be apparent from a casual glance at them through the perforated, concave curvature of their protective black grilles.)

The proprietary doping compound applied to the Scan-Speak beryllium 1" dome and its large rubber surround is also the result of a long-term collaboration between Albert and Scan-Speak, in an effort to prevent even the slightest perception of harshness.

The 3" aluminum-foil ribbon used for the Rear Ambiance Tweeter was designed by European speaker-maker RAAL, and boasts an upper frequency extension of 60kHz.

The crossover is constructed from the finest parts available, with all final components selected by ear. This particular crossover circuit, unique to Von Schweikert Audio, is a time-and-phase-aligned design that represents the latest iteration of its ever-evolving Global Axis Integration Network. With a goal of sonic “invisibility,” the crossover leverages the advantages of servo-control and the use of very few parts in series with the drive units. Most of the constituent components are in parallel ground shunts to control phase and impedance. The crossover parts are hyper-expensive—including premium devices from Duelund, as well as Jensen copper foil and Teflon/beeswax bypass caps. The main capacitors are Mundorf Supreme Gold/Silver/Oil. All inductors are copper foil, resistors are Mundorf metal film, and all internal wiring is Delphi’s MasterBuilt Single Crystal Copper.