uif they are "clipping" then you need to turn down your gains.
What do you have the horns corsed over at?
Haev you tired addign an external eq to attenuate?
I had your exact setup probably 4 years ago...sounded like sh*t...tweaked on it for about 6 months...finally chunked the whoel project.
There is a reason why everyone raves about wetsounds, NVS ect....