What once was a marvelous listening experience has turned into a diffuse, muffled, lifeless, boring system!If these symptoms are particularly extreme, they would seem to be consistent with a polarity reversal in one (and only one) channel.
Just to be sure something simple isn't being overlooked, are you certain that + and - aren't reversed on one of the speakers, or on the corresponding amp terminals? Also, if you are using XLR cables for any of the analog interconnections in the system, that you weren't using in the previous location, a wiring error in one of the cables (interchanging pins 2 and 3 at one end) would have the same effect. Perhaps an erroneous setting in your playback software could also do the same.
Also, what DAC are you using?
Regards,
-- Al