When I play the low E string while plugged in, it seems to be way more responsive to volume than all of the other strings combined. At first I thought it was the amp or the PA, then the wattage, but I tried it at different places and got the same result. I bought a feedback buster to see if that would help, but it remained the same. Even when the bass on the guitar and amp are turned all the way down, the low E and A strings still seem to be very responsive. It's a noticeable amount of volume difference between them. Any suggestions?