Speaker purchase - LOW ceilings

Thank you Pdreher! I purchased them. We will see how it turns out. In the meantime, if someone else can give additional tips to make the sound better in a low ceiling room, I would appreciate it :)

My listening room is 15 x 21 with ceiling height varying from 6 to 7 feet. I don't have any problem with my current speakers and small sub in this room.

Your room, while not ideal, will probably benefit from room treatments and possibly a preamp with some sort of balance adjustment, depending on where your speakers will be situated in relation to the ceiling height. The ProAc Studio 125's should be fine for that size room... and maybe even a small subwoofer.