I currently have a KLH ASW10-120 10" 120Watt powered subwoofer. I'm satisfied with the power, but not quite satisfied with the clarity. I currently have the cabinet stuffed w/ cabinet stuffing and the port plugged with some socks. This has taken away some of the boomy echo sound, but the bass still isn't tight at high volumes. Does anyone know of any tuning/tweaking/modifying i can do to what i currently have to improve performance? Could i replace the coated paper driver with a poly or aluminum car audio type driver? What will happen if the impedances are different? If not, i'm interested in the Sony SA-WM40 and the JBL PB-10. If i get a new sub, my price range is around $200 shipped or purchased in a store, since it will be a birthday present. Do you have any other suggestions? Thanks!