Since the 770 has specs listed for loads at 4 ohms or 6 ohms. And I have 6.1 (sometime in future 7.1) my FL/FR are at 4ohm with all others 6ohm.

I’m having to bump the center to bring it in line with the mains and thought this might be due to, yet this is not too much of an issue at the moment. And the surrounds are in line well.

What are problems I might should worry/look for. Over heating the amp? anything else?