Alright for most of my live performances iv been using a boss noise supressor pedal, which gets rid of all the feedback which is nice, but it cuts off a lot of sustain and iv been told taht noise gates/suppressors instead of cutting them off, reduces extra noise (squeeling , fuzzing, and buzzing) without suffering your sustain. So iv been building a rack setup for my stack and recently picked up a behringer quad multigate pro. When my amp is maybe at 2 it seems to do just fine , my susstain is still there and the feedback is nonexistant. But when i want to crank my amp say to 7-10. My amp doesnt get louder, but the sound gets really REALLY fuzzy and incoherent of anything...its really strange and im not sure what its doing, any thoughts? Its like the volume knob doesnt do anything
Which mode do you have the gate in?
You can toggle between gate and another mode (I cannot remember the name of which, and I'm at work right now )
Secondly, the Behringer Multigate Pro (This IS the model you have, correct?) is really designed to work with microphones and not so much with guitar amps.

However, if you'd like, I can test mine on a few of my halfstacks when I get home to see if I have the same issue. Then, if I can dial it out, I will let you know.
1979 Gibson Les Paul Silverburst
James Tyler Variax JTV89
Schecter C1 Classic
Ibanez RG520QS
Greg Bennett Torino TR4

Mesa Boogie Dual Rectifier
GSP1101 & Pod X3 Pro
Peavey 5150 & JSX
Bugera 6262 & 333XL
Carvin V3
Spider Valve HD100
I just have the mode set under gate, and i actually did not know that....ppl workin at guitar center must really know what theyre talkin bout nowadays right? haha thanks alot man it would help a shit ton
Well no matter what you do, you will lose sustain if you use a noise gate/suppresor when the signal level drops bellow the threshold. Have you tried running your rig without a noise gate? If the feedback is uncontrollable then drop the gain and turn the volume down on your guitar when you aren't playing.
this i know sir, but my issue is the noise gate itself when i plug in this particualr gate is ****s with my amp