Where did the sound go?

I recently added a plasma tv to my listening area (the living room) and decided to set up my system in the basement since I needed to take everything apart to make room for the plasma. I was thinking of adding a theater and though this would be a great time to experiment with the acoustics in the basement. I set up the system in the finished off basement. All I can say is "where did the sound go?" Everything sounds hallow. Even my wife said it sounded empty within 30 seconds of listening. The only difference is that everything was plugged into a standard wall outlet(which is shared with other outlets) instead of a dedicated line from the fuse box. The walls are drywalled, no isolation behind the walls tough, room size longer instead of wider like the living room, ceiling is 1 foot lower, and the temp. is 64 instead of 71. The music has less substance and less depth. I thought the equipment wasn't warmed up because it was in the basement but even after an hour of playing, no major change.
Any thoughts or similiar experiences?
Troy