How big should center spkr be to set to "large"?

Could part of the problem be putting the center channel on top of the RPTV? Putting the speaker on a stand in front of the RPTV just below the picture might improve performance. I favor a good sub, and crossing over the other speakers at 80Hz.

db

I have actually tried both small and large settings for my current setup. I have no problems with clarity or bass response with the center speaker set to large. All of my speakers are set to large and i don't use a sub. I have also used a test disc with a sound pressure meter and the 570 will do 25Hz easily in my room.(Can do 20Hz but not too audible mind you, but it will do it.)
Could be as simple as different equipment,different results.

"Could part of the problem be putting the center channel on top of the RPTV?"

Yes a little, but the main problem is a dramatic spectal balance mismatch between the main speakers and the center, further aggravated by there being no sub. Which I realize he cannot buy, and that's ok just swap the 570 for a Silver Screen should be a wash financially.

Also CDW with a sub in the system, many receivers will allow you to set the crossover at 40-60-160hz and the range can be covered at 1dB to 10dB intervals. A center like the 570 I would crossover somewhere between 50 and 60 hz.

I played around with it some more tonight, watching 5.1 movies and a Black Crows concert on HD cable.

Actually, tonight I could hear no ill effect from setting the center speaker to "large". It did't seem to cause any loss of clarity in the center speaker, nor did it seem to cause any loss of overall bass. I really liked the overall sound with that setting.

I am going to try it on some DVDs and HD DVDs as well.

Mtrot, How is your setup working out?