I took advantage of Big Bs offer of upgrading my Larger sub to essentially the VSS sub. As I understand it, the VSS subs at 2007 CES were not true VSS subs, but upgraded Larger subs. They sounded very nice.
The upgrade kit consists of the new 15" driver which looks like a Eminence Kilomax Pro 15A and a plug for the 12" driver that is being removed.
Today with the help of a friend who is an experienced DIY speaker builder I installed the upgrade. The hardest part was getting the old drivers to come out after the screws were removed. The gasket material between the drivers' metal rims and the MDF of the speaker cabinet acted like glue. We eventually got the drivers out by prying out the 15" and then pounding on the 12" from behind. Some minor cosmetic damaged was done in the removal process. The Larger is filled with Glass Wool. Using gloves the Glass Wool was carefully removed and placed in a large garbage bag. You don't want to inhale any of the glass dust and fibers.
Since the two drivers were removed, this was the ideal time to apply Black Hole 5 to the inside of the cabinet. The Black Hole 5 needs a smooth surface for best adherence. So the inside of the Larger, which is painted, was scraped to remove globs of glue and plobs of paint. The inside of the cabinet was then vacuumed out as Black Hole 5 will not adhere to a dusty surface. The Black Hole 5 was then cut to size and applied. The VMPS price list recommends using three square feet of Black Hole 5 for each sub. We installed slightly less than 8 square feet. In order to work effectively, the edges of Black Hole 5 need to be at least one inch away from the sides and also from other sheets of Black Hole 5. We left a two inch gap or more around all the sheets.
The 12" plug has a 1/4" circular piece of Masonite with a larger diameter attached to the top to simulate the rim of the driver. You need to drill 8 holes in the Masonite so that you can use the 8 screws that you had removed to affix the plug to the cabinet. Be sure to place new gasket material between the Masonite and the cabinet.
The new 15" driver is a dual voice coil; i.e. it has two pairs of spring loaded binding posts. My Larger sub had no crossover and had a pair of binding posts for each driver. Thus, it was a simple matter to attach the two pairs of wires to the new driver. Since I have two 540 watt plate amps instead of the 1000 watt plate amp that Big B installs in his powered subs I did not need to put jumpers between the two pairs of binding posts.
The new 15" driver has a thicker rim so it does not lie flush with the cabinet face. It protrudes about a 1/4". Also the Masonite is attached to the plug apparently by screws. The recessed screw holes are plugged with a soft putty (mortite?) before spray painting the outside surface of the plug black. Paint does not stick well to soft putty. Thus, casually brushing the top of the plug to remove dust removed the paint from the top of the three puttied holes. The protruding rim, the missing paint which shows the white putty beneath and the slight cosmetic damage caused while prying the 15" driver out of the cabinet makes keeping the grill cloth on mandatory for me.
So with the upgrade complete my friend and I sat down to listen to the new driver. We ran some deep bass test tones for a couple of minutes to loosen up the spider. While doing this we noticed that the cabinet did not vibrate as much as before. That Black Hole 5 really works. We then started integrating the new sub into the system (I have RM30Ms) by playing pink noise and noting the room frequency response on a Phonic PAA2 meter. The first thing that we noticed is that the new driver is much more efficient than the old drivers. With the old drivers the gain setting on the plate amps had been 3. We had to turn the gain down to 1.75. We also noted that while the old drivers had dropped off sharply at 30Hz, the new driver did not drop off until 25Hz.
Without being able to do A-B comparisons between the original Larger and the Larger with the new driver and Black Hole 5, I can't give a precise description of the change in sound. Big B said that the new driver is more dynamic. I agree with that. Better leadng edge transients on bass slams. Is the bass better, tighter, with more natural timbre, I can't say. I am happy with being able to go 5Hz lower in the bottom octave since I play a lot of music with synthesized bass that does go down to 20Hz. I figure significantly less cabinet resonance has to be a good thing. The increased efficiency of the new driver should allow it to play considerably louder. However, since I don't play music at rock concert levels that is of no value to me. So is the $350 for the upgrade kit and the $100 for the Black Hole 5 worth it. It is not the best bang for the buck that I have done to my system. However, it is a worthwhile improvement and I am happy with the results. I also am glad that I am keeping my system up-to-date.
