Just completed remodeling basement and now have a longer HT space and would like to go to a 7.1 type setup. Harmon Kardon AVR 320 powers the system, but it's kind of unclear how to feed it the two additional speakers; the manual says they must go through another amp. I assume the 320's installed power supply can't drive seven speakers and a sub.

Understand I could just upgrade to a 7.1 RX, but my current rig works just fine. Just wondering if there's a simple way to get two more speakers integrated.

I see that this is an older receiver that doesn't have full support for 7.1. If you want to drive 7 speakers with 7 channels then you need 7 amplifiers. The reciever only has 5 amps. Hence the need for a separate stereo amp. Also it doesn't have Dolby PL IIx which is what many people use to direct sound to the rears. But it does have Logic 7 and that will do the trick.

Ed