I turned all my eq's off. I turned HU to 3/4 of volume and gain down. I got a DMM and set it to the 200~ setting. I played a 50hz tone. I may be dumb or something but wut do i do next. I put the positive wire from the DMM on the positive post on the amp. I put the negitive wire from the DMM to the negitive post on the amp. When i did this my subwoofer was still connected...does this matter? Anyway when i put the DMM on it only registered to like 5 on he DMM. Help plz.