my VSX-0814 overloads when I have the volume on 33 or less. I have two wharfedale 9.5 diamond speakers hooked up and a wharfedale sub pre out separate power. All wires have been checked. One speaker recently fixed. Have a few people over for a dance and it overloads. I never have it higher than 21 on the volume. Got a large lounge heaps of ventilation around the amp etc etc. Can any one offer educated suggestions?