Olness it sounds like you found the sweet spot once before in your old room and you can do it again in this room too. The thing you have to remember is that it is a new room, and if like you said everything is setup just like before then it is probably not optimized for the new room. Yes the concrete is going to make a sonic change but, the size and shape of the new room will have just as much of an effect on your sound. This is assuming of course the dimensions of the two rooms are different. Your listening area is probably sitting in the middle of a null and not a peak. Try moving the sub around a bit like old times if you have not already.