What Receiver Settings do You Use for Music CDs?

I went with a 5.1 system for High Definition TV watching as well as DVD watching.
The music concerts are esp. good in DTS or 5.1 Dolby.

But what do you listen to your old (or new) music CD's in?

I just used 2 speaker mode at first at that is likely what they were first designed for, but my receiver (H-K) has so many options.

Which settings give good results? Or do many of them just channel the same stuff through the fronts, centers, rears, etc?