Ok, after doing some research I have come up with an explanation. Our ears don't hear bass as well as we hear other frequencies. The 6db boost is supposed to compensate our ears for the difference in sound levels delivered to the mains and to the sub. It is assumed by the designers that there is a gradual roll-off of hearing ability that reaches -6.2dB at 20 Hz. -- that means the average person listening to a 20Hz. tone needs +6.2dB more sound pressure for lower frequencies than a 1000Hz. tone for both tones to sound equally loud, hence the 6 db boost. It should work for a typical Home Theatre application.
I currently have one of these operating in my HT system:
I have not been particularly happy with it. It works ok but it doesn't seem to deliver enough deep bass punch in my 20x40 living room, and the sound is very localized.
I picked up one of these with a bad amp at a pawn shop for cheap:
What I planned to do was to fix it, and then try two subs in the living room, one at each end, and see how I like it. At this point, I'm going to give the board a try. if it doesn't work, I'll use them in the kid's game room for their video game set up and buy or build something better. The reason I like these subs is strictly cosmetic, I have read a lot of criticism of them, but the one really nice thing about them is they look great in the living room, so I'd like to make them work. I guess at this point, I'll let you all know how it works out......Edited by kvining - 1/4/13 at 8:01am