how do you tune your amp???
What are we talking, crossovers, gain settings, mono block's, or multi channels, you need to be more specific with your question.
well its called an instruction manual you will find everything you need to know in one of them
turn amp gains to nill , deck volume 3/4 bass and trble flat . gradually bring up gains and adjust hi or lo pass filters as required untill you achieve best sound. if 4 ch or multiple amps set 1 amp or channel at a time. if running subs then turn hi pass filter on for front and back but dont set too high a freq . adjust to your own taste. don't push gains higher than 4/5 or h/u above 80% as you will get system distortion.