Various questions

[Imti]

Newbie

I need some advice. Actually, I need lots of advice.

Here goes.

I was given a Polk CS20 center speaker. I then got the itch to upgrade my audio system. I browse newegg and found the entire Tsi line; however, the prices was not in my budget. I read on this site that the Tsi line is almost the same as the Monitor line. I found the M70 and M60 for about 1/2 and 1/3 the price of the Tsi500 & Tsi400.

I decided to get the M70s for the front and the M60s for the rear. I understand from some reading that the center and fronts should be from the same line. Is there any compatibility issues with the CS20 and the M70s?

I also need to upgrade my receiver as well. I found some Onkyos on Accessories4less. SR706 for $499 and SR806 for $599. Any suggestions? I know these are refurbished. I would like the ability to upscale my SD television signal.

Here's another issue I have.

Should I Bi-amp the front speakers using a 5.1 setup or should I get two additional speakers for the back using a 7.1 setup? The room size is approx 15ft X 20ft and my audio system will mainly be used for 70% TV (blu-rays, HD & SD television and some DVDs) and 30% music (CDs and MP3s).

Would a 7.1 setup give me a cleaner sound than a 5.1 setup with Bi-amp fronts? Based on my usage above and my room size, which setup would benefit me the most.

Any suggestions on a sub-woofer?

Finally, I did some reading on Bi-wiring. Can you bi-wire rear speakers? Is there an enhancement in the sound quality by Bi-wiring the rear speakers?