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?
You are finding out what a room can do to the sound. I have witnessed this several times now. Your speakers will have to be in different locations than they were in your old room. Move them around A LOT and see how they need to be for your sound to integrate well. For hollowness, you may want to bring them into the room a little bit. The golden ratio (1 side : 1.618 back) would be a good place to start IMO. I am sure you can find new speaker positions that will work well in your basement - but it will take some time and effort. It is normal procedure.

As Arthur states, it is the room. You will have to completely rethink your position and the placement of each speaker. Sometimes the position of the speakers for best sound does not fit well with watching your display. You are probably sitting in a null with dips in the upper bass and lower midrange. You will have fun and frustration experimenting. Good luck!
And how is it furnished?

Upper bass and lower midrange is what is missing the most. The room has furniture in it, perhaps not as much as upstairs but I thought I would get more open sound, not less sound. I'll play with the speaker placement and listen to the differences. I knew there would be differences but never thought it would have been this dramatic.
Had a very similar experience when I moved my system into a family room with cheap wood paneling on the walls. Three of the walls were inside walls with no insulation. My system never sounded so lifeless. I moved it back.