Citation 7.1 CUTS out, do I need More Power?

I have a 7.1 which I am using in a bridged mode,
450 x 2 @8ohms and at a very loud, close to clipping probably, the amp will cut off, then back in, then off, then back in, and so on. When I turn the volume down,
it is fine. Is this some type of internal circuit to prevent damage to the amp/speaker?

Anyone?

Also, does this mean I will need more power for the volumes I am listening at?

Thanks,
Dan