I just recently moved into a new home and the theater room is in the basement. In my old house, I used to be able to feel the bass from the sub, but no longer can. Everything is set up like I had it in the old house, except the theater room was on the main floor.

I have the 990 set to small speakers for the fronts, center and surrounds. The fronts and center are crossed @ 80 and the surrounds @ 100. I have bypassed the crossover on the SMS and am letting the 990 do the work. I have adjusted the SMS and have a flat response curve.

My question is this-Is the concrete in the basement absorbing the lower frequencies? If so, what can I do?

If anything, the concrete will reinforce the bass by providing a more solid foundation than a wood/joist floor will. What you are probably used to is the floor in your previous setup transmitting the low frequencies. It may even be possible that the floor from the first floor, overhead in the basement, is soaking up some of that bass energy and taking the impact out of it.

Some bass shakers may be the answer.

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.

is the basement larger than your old ht room. I wold try putting the sub in a different spot Like in a corner, but about one foot from each of the corner walls, that way the sall can reflect and give you the ipmression of more bass.