VR 2 Speaker Construction
At first look the VR-2's appear to be put together quite well. The front baffle was narrow which minimized diffraction. The tweeter was near the top of the cabinet at ear height and the midrange and bass drivers outer flange was right near the edge of the cabinet. This design should allow for excellent sound stage and imaging. Also note that the woofer was above the mid-point of the cabinet which helped avoid resonance's of the cabinet itself. After removing the midrange and bass driver I found several more good design practices implemented by Von Schweikert Audio for example, the interior walls all had damping material. There was also ample shelf type bracing in two different directions which stiffened the cabinet. I felt around inside and found that the crossover was placed on the bottom to minimize magnetic flux from the drivers interfering with the crossover circuitry.
One thing to notice from the picture is the white acoustical stuffing around all the drivers which was used to slow down the speed of sound. This technique made the cabinet appear larger to the driver effectively giving a better bass response. At first I thought that the designers at Von Schweikert Audio completely stuffed the box which would have been a bad design practice because the space between the woofer and the port should be left clear. Apparently some of the stuffing had fallen and blocked the port, so I pushed it back up and the space was then cleared. While I was feeling around inside the cabinet I found some surprising things. For example, there was no separate chamber for the midrange driver. Although from the outside of the cabinet it looked like two identical woofers they were not. In the picture notice the woofer on the left with a larger magnet and the midrange on the right with the vented pole piece, i.e. the hole in the magnet.
I have never seen a design quite like this before. This type of design allowed low frequencies of the woofer to impinge on the midrange cone and the midrange frequencies to impinge on the woofer cone. This inteference is typically controlled by having separate chambers for each driver. Dome tweeters are typically sealed so they are not affected by this effect, as was the case with the VR-2's. But the woofer and midrange in this design were not the same driver or frequencies. Mr. Von Schweikert offered reasoning being their unique approach to minimizing performance issues which could result from interference and it can be read in its entirety in the addendum of this review.
Von Schweikert Audio implemented a Transmission Line design in the VR-2's. Based on my initial understanding of this term, I searched internally for tapering within the cabinet. The most popular text book Transmission Line designs provided some type of channeling or labyrinth for air to flow from the woofer to the port. Upon further study, we have found that the actual purpose of a Transmission Line was to absorb energy, not necessarily set a line length. Furthermore, there are many different types of Transmission Line designs, one of which includes a Pipe Transmission Line.
The VR-2 design provided sufficient bracing and a separate chamber on the bottom where the shot could be installed, however it did not follow the standard labyrinth type Transmission Line we were most familiar with. Instead, Mr. Von Schweikert informed us that the VR-2's were more of a hybrid design based on the Pipe Transmission Line concept which was covered at length on their website. For more information on the VR-2 Transmission Line design please feel free to check out their website with the following link: Von Schweikert Audio Transmission Line Design .
The internal wiring consisted of hookup wire about 16 gauge in size. Although the wire seemed small, given the short lengths, I doubt they would make an audible difference.
The drivers them self appeared to be well made. The woofer and mid-range had an aluminum cast frame and as mentioned before the midrange had a vented pole piece which allowed for cooling the voice coil. The tweeter was a soft dome with ferrofluid which also helped cool its voice coil. We were pleased to see that all four drivers had magnetic shielding for placement near a television.
The terminals on the VR-2's were five-way copper binding posts plated with Rhodium. There were two pairs to make the speaker bi-amp ready by removing the bar that connected them. On the bottom of the cabinet was a removable panel for adding the suggested lead shot to the cabinet.