Help problem with Soundlab Dynastats

So I just helped my non-audiophile dad hook up his Soundlab Dynastats which were previously connected to a Yamaha DSP A1 receiver to his new improved setup consisting of a Bryston Sp1.7 and 9B ST REG 5 channel amp. The speakers had to come up from the basement to the main floor, a move which I wasn't involved with. When I hooked the Dynastats up to the Bryston Electronics, they sounded totally muffled, both speakers. Terribly wrong. I hooked a couple of pairs of cheaper speakers to the Brystons and they sounded fine. Adjusted the bias and tone controls on the Dynastats - no improvement. Any ideas? Apparently they were sounding absolutely great with the Yamaha just a few weeks ago.....