I have some older ('92 I think) sony tower speakers (ss-u421-av) hooked up to my new pioneer 1019ah reciever. I'm currently running it as a 5.1 system but it bugs me the their are two channels on the 7.1 reciever that are sitting there doing nothing. It just occured to me, however, that reciever supports bi amping the front main speakers with the unused surround back channels. This sounds like something I want to set up, but the speakers don't have the extra binding posts to bi-amp or bi-wire. Is there any way I can modify them to make this work, or should I just forget about it? If anyone's got some suggestions I'd be very grateful.