Well first off... it kind of depends on what amp you're running it through. Some speakers can't handle certain frequencies and "break the sound up", making it sound not-so-desireable. If the pedal came with a booklet with settings in it, I would suggest that you consult that. I don't own any MXR pedals, but my Boss pedals all come with a reference for suggested EQ settings. But I'm guessing your amp may be the problem...