Sound issues

Here is my current set up. Marantz AV7701, Mac MC205, Oppo 103, PS3, SF Liuto towers, SF Liuto Smart center, SF Toys Monitors (on order), Audioquest GBC speaker wires. The bass is there, but the center seems to be over powered by the towers and missing the highs and mids from the towers. In fact it sounds worse than the set up at the store running a Arcam AV. I have a old Monster surge protector, could that be it? Is it the speaker cables? I'm just at a lost, opinions, thoughts?