OK here's the scenario. I've got a 5.1 subwoofer/receiver with speaker outs. This is ok for the front & center speakers, but our house has two RCA wall plates installed to connect the rear surround speakers to. So I need some way to convert the speaker wire going out from the sub to RCA so I can plug into the wall plate. Luckily, the surround speakers accept both RCA & speaker connections so I wouldn't have to re-convert the wire back to speaker.

I came across a Hi/Low Impedance adaptor on Ebay, which seems to fit the bill. While it's normally used for car stereos...I don't see why this wouldn't work. Mainly this system will just be used for background music, and not house-thumping home theater. The system is a Theater Research TR-502. What do you all think?