What am I doing wrong?

Ok, I am using X-fi with Vista, 7.1 analog config with my receiver. Got X-fi calibrated, got cm-140 cal file loaded, have my cm-140 positioned. I go and click on the measure and then to start measure and sound is only coming from my center speaker.

[JohnM]

Your receiver is doing some multi-channel processing on the signal (e.g. Pro Logic or PLII) and deciding that anything that is on both left and right channels should be redirected to the centre. Set it for a processing mode that only does bass management and no steering, which would usually be called "stereo" or similar.

Ok, fixed that problem, now all I gotta do is disable the front speakers so that the sub is the only speaker active when measuring.

[JohnM]

Just unplug them