Yeah. Before swapping speakers and such it could be something as little as having the QS8's set to "large" in the thx mode. The QS8's are not full range speakers and should be set to small with a crossover of 80hz or 90hz. Double check "large" or "small" and the crossover settings when the thx mode is activated on the receiver.

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne