Not sure if this is the right place to say this, but I built a dual-driver open-baffle servo-controlled subwoofer from GR Research yesterday, and it sounds heavenly. The musical sound is natural, relaxed, full, and reassuring - compared to anything I've heard in my home so far.
(Still need to cut & apply the NoRez, etc.)
Previously I had a seven-inch "REL" subwoofer in this same spot. The "REL" sub would send some of the bass directly at the floor, and maybe that's why I frequently would get bass feedback sent back into my turntable if I had the volume up to even a moderate level (but still quieter than if a live jazz quartet were in the room). The new GR Research sub seems to have completely eliminated this feedback issue, besides just sounding so much better overall. I think the bass was also feeding back into my tube amp, because apparently vacuum tubes are microphonic. I don't know if it's the "open baffle" design that protects the turntable & tubes from the bass feedback issue (i.e. the "room boom" / room "pressurization" that some people talk about), or if it's simply the way the REL sub pointed some of its sound directly at the floor. I guess I'm still not clear on what "room pressurization" is, but the proof of the pudding is in the eating as they say, and this sub design definitely works much better than competing products, in my opinion.
You have another very happy customer here; thank you Mr. Richie and others.
