Hi I've used Black Hole many times, and thre certainly can be advantages. Beyond any internal sound treatment benefits, it does stiffen just about any cabinet. Clearly the results will be greatest in a cabinet that doesn't have adequate bracing, which doesn't describe the HT1. The only point I would like to make is that the stock interior sound treatment that Jim provides is amazingly effective. Jim just sent me a tall, fairly narrow prototype floor-stander cabinet for project I was interested in. I always shout through the woofer holes to test whether internal refections are causing any audible boom or other coloration. There is almost always some problem, particulary in tall column cabinets. In this case, and in the case of other cabinets Jim has sent me, I didn't hear a thing. It was completely dead. So you shouldn't think that Black Hole is necessary to make up for an obvious or serious deficiency in the stock treatment.