and will bring down your walls in that application. I faced a single EV 15bwk driver against the wall, near a corner, driven by a measly 1875 chip amp...30 feet across the room all kinds of stuff was rattling and buzzing, and this was at "reasonable" levels. If you DO use the 555 for subwoofer duty, check or replace the 47uF caps in the feedback loops, my 545 had "premature" roll off at the low end in one channel which drove me batty swapping speaker polarity till I figured out it was the AMP stupid. You may be just as well off to use a "plate amp" from PE, one with a remote control would be nice for setting the level from the listening position, and the built in bass boost won't hurt. Then you can drive the Theater 4's with the adcom:)adcom 555 driving jbl 4648a-8's
adcom 545 driving altec 902/511's
marchand xm9L set at 800Hz.
ginger baker sounds a hell of a lot better in my LR than my neighbor's drums from across the alley behind my house:) Sam