Changing the crossover should be all you need. If you find yourself experimenting with Pro Logic II Music mode (surround processing for two-channel sources), you would do well to re-visit the three settings under Surround Config, but that's sort of secondary.

I hooked up my surround back L/R and its not playing any music. I tried setting it on 5ch and 7ch with no luck.

Dumb question. If I only have 5.1 speakers and I am awaiting on two (makes 7.1) to arrive should I plug the two speakers I have now into the Surround Back L/R or the Surround L/R? I figured they should go in the back.

I ran auto setup and it found the back surround speakers but for some reason it didn't set the speakers to "small" all thats there is ---.

Also, I can't change the channel calibration. there is three -'s for the back speakers.

Thanks,
cugine

They need to go on surround, not surround back. The surround back speakers are 6 and 7, while the surround (side surround) are 4 and 5.