Report "Can't get any gain without feedback when using my new shure sm81 mic and the xenyx x1240usb fx mixer. keep the speaker way out in front of me. no montiors. using just a hair of reverb and compression. have to pull the lows on both the mixer eq and the powered beringer eurolive b212 speakers all the way down...and that STILl doesn't allow for much gain. slight ringing even when the speaker is way out in front of me. am mic'ing an acoustic guitar but keeping the sm81 "back, down and away" please HELP! have the frequency rolloff setting on the mic engaged, too. gotta be able to use this mic in live settings, no? i'm stumped!"