anyone know of a good, hopefully inexpensive subwoofer control box? i have an audiocontrol richter scale and like it. it is in the stereo room. i am looking for a sub control box for the home theater that can be plugged in from the "sub-out" on the reciever, then into the sub plate amp. i don't want to have to move the HT set-up and reconnect everything, i just want something i can plug inline with the sub-out cable. i prefer a unit that has a subsonic filter, and setting for different frequencies to level out and dips/peaks. thanks!