Darren,

Try and reduce the center-channel level with the menu in the Yamaha and raise the level of the left and right main speakers (relative to the center).

I also suspect the Yamaha center is fairly colored (it may have a nasal "honk"), which could make it seem distractingly loud.

You can order Avia on Amazon.com.

Regards,

Alan Lofft,
Axiom Resident Expert (Retired)