Hi all. Thank you for your comments.
As kcarlile mentioned, I have used the autocalibration (with the microphone that shipped with the receiver). I have not bought an SPL meter for more precise/involved set-up.
I will manually increase the centre channel setting tonight. The reason I was hesitant to do this was because TV and games already sound perfect. That said, I could make another MCACC setting and switch back and forth, depending on what I was listening too.
In my nervous buying state, I was hoping someone would have something like this to say...."I had Athena's ASC1, then switched to the VP150, and I couldn't believe how much easier it was to hear dialogue".
But that would have been way too easy!
