i am using a 60 watt hiwatt bass amp as a slave for a marshall 150 watt bass cab,whilst i can get a good bit of volume out of the set up and the cab sounds great at lower volumes whenever i drive the set up in heavier songs i get a very distorted sound.
i use an american standard fender jazz bass and the hiwatt amp has a 3 band eq comprising middle,bass and treble with a contour knob and a presence knob and the usual gain and volume controls.i have my neck pick up on full and the bridge pick up at about 4 the tone knob is rolled right off.i also have a bass eq pedal but dont use it much as it distorts the sound even when the gain control is set in the middle (0).my eq settings are bass 9,middle 7,treble 0,presence 2, contour 2,
these settings are fine whe the volume and gain are set at half way but once i go high which the band im in do on a few songs i get a very fuzzy distorted sound,so im looking for a bit of a point in the right direction for how to set my gear up and some settings for my controls.
You're simply pushing the amp too hard. How high is your master volume? With bass at 9 you're sending so much bass to the speaker it's bound to break up. Even my 15" breaks up when bass is on full at higher volumes. Temper your EQ settings, make them less extreme and go from there.
I agree, the amp cant handle that much. I would try bring the bass down and maybe the mid a little too. my 4-10s will pop a little when a play hard.