I have a sony Pre/Pro. Question I have is I set up all the speaker levels with a SPL meter. Why is it that if I do a freqency sweep with a CD PCM bit stream all the sound comes out of the center channel. L/R and Rears are just about non existant. I cycle through all the supported modes (Sony ES9000E Pre) and only the 2 channel modes output to the LR other wise it all goes to the center even when I crank it down with the sound level.

Probably the way the CD is recorded.

Is there actually no sound coming from the left and right speakers (i.e. your head is next to the driver and checked this) or does it just sound that way from the listening position?

If there is indeed zero sound coming from the L&R then try another CD. Does the problem persist?

If not, your calibration disc is likely in mono. Your receiver's surround modes are likely getting "creative". If you are trying to calibrate L&R with the sweep, you should be using the direct 2ch mode, not the surround modes.