One more suggestion, though: Using that center channel speaker is going to hurt the potential sound quality overall. I would remove it, and set your receiver to output a phantom center image.
This means, when you don't have a benter speaker, that your receiver splits the center channel info between your L and R main speakers...in this case, much more capable speakers.
There's a lot of info on the center channel, and putting that through that small speaker will hold you back.
::::::: “Yum. I'd love to gnaw on those with my ears." :::::::