Why Do I Get So Much Feedback?

[brightorangband]

Ok here is my setup
I use a sm57 into a mixer for my vocals and stand behind the speakers if I turn the volume to 1 1/2(which isn't enough volume) and have treble or mid at 0 cause if I turn it past zero I have a storm of feedback. keep in mind I play in a 24' by 28' wood walled concrete floored room I have a couple rugs on the floor to try to keep the floor reverberations to a minimum. but I would like to be able to turn up the treble to atleast five and maybe some mid. Any Suggestions? it is killing our practices!

[fenderphil]

your speakers are facing away from you. thats an issue.

are the walls concrete? if the sound is bouncing off of the flat walls, then its being directed back into the mic.

usually not a good thing.

put something on the wall that the speakers are facing\

OR if the speakers are wedge type speakers, then put them on the floor FACING you.

you'll be surprised by the results.

[brightorangband]

Thanks! I'll Give that a try

[Pilgrim]

Do a bit of searching and study some acoustics of sound bounce. Sound waves are like the path of a billiard ball - they keep bouncing. If you put a mike in front of speakers, it's a straight line for feedback, but even if the mike is behind the speakers, you'll get sound waves bouncing around into the mike.

Any hard surfaces in the room make sound bounce more easily - and hard, parallel walls (or floor and ceiling) amplify the effect.

This is one reason I do NOT like Omnidirectional mikes for vocals - they pick up in a 360-degree pattern, making feedback more likely. Your SM 57 is a Cardioid pattern, which helps - read the user's manual, then point the butt end at what you do NOT want the mike to hear. If the speakers are in front of you, that becomes the thing you do not want it to hear.

But if you're in a small, live room, you'll just have to turn down.