turn it up all the way and set ur gain . that way you will not clip when you are playing with it. the purpose is to turn down ur bass. for comps i use my bass knob to roll into my burp.. its better on the equipment
Hold it there guys.... Theres two types of "bass knobs"
If it came with the amp its usually a bass boost control in which case it should NEVER be used. All bass boost gives you is clipping and distorted sound.
If you know for sure that it's a level control, then you can use it as kind of a remote volume control. If you don't have this, look into a PAC LC1. It connects in-line on the RCA cables at the HU and gives you a level control you can use with any amp.