This is my first post. I have a Kustom 200 B1 amp. With my bass volume switch all the way up, then start to turn the amp volume switch up. The volume starts off low then with a 1/16 of a turn the volume is very loud. I have to turn down the guitar switch way down. Any idea's what is wrong. The bass cabinet is 2-15s 4homs speakers wired in series gaining me 8ohms. Thanks