Massive Audio NX4 - protect mode when ran pretty hard.

[gunz4me2 10+ year member]

I owned a pair of Rockford Fosgate Punch 250a2s from the same time frame as the 800a4 until 2006, and I can not for the life of me remember if those had the built-in EQ from the factory. From what you are describing, it sounds like they do which would be a slight bump at 45 Hz and another bump at 12 kHz. That would account for your pounding on the low frequencies and potentially muddy midrange area.

 

[olds97_lss 10+ year member]

It does have a high pass, low pass and through switch that I have set to through. Along with punch gains that I have turned down. The adjustable crossover appear to be used only when the filter switches are set to lpf.