With 3 Sierras across the front, 2 170SE rears, and SVS 25-31CS sub, would you set the Sierras to full range or crossed over at 80hz? I assume that the 170SEs should be crossed at 80hz regardless of the answer to the 1st question.

Are there different answers for movies and music?

The Panasonic SA-XR57 receiver has crossover settings at 80hz, 100hz, and 120hz.