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[xguitox]

hey all.

looking for some advice when it comes to eliminating vocal feedback in FOH and Monitor mixes -  i cant quite bring them up over the stage gear....

here is some detail about my system
-16 channel mixer with low, low-mid, hi-mid, hi eq on each channel
-2 way crossover
-2 behringer 18" subs - powered by mackie 1400i power amp in stereo mode
-2 peavey full range cabs ( 15" woofer and 12" horn ) - powered by 800w peavey amp in stereo mode.
-2 monitor mixes ( 1st mix in 2 wedges front of stage, 2nd mix is in single wedge for drums ) - powered by 600 watt power amp in stereo mode

using sm58s for vocals...

i have no problems with my drum and instrument mics feeding.... but i am having a hard time bringing up vocals in the mix without feedback.  i have to turn them down between songs to get rid of ring tones while vocalists are speaking.... i know it's feeding during songs... but i have to bring up the vocals so they can be heard.... i tried gating, but the mics usually pick up everything on the stage and it's hard to get the threshold up without chopping up the vocals....

i guess i'm just looking for some tips on a very limited budget.... we are a new venue and don't have much money to throw into the sound system.... (gotta pay the bills)

i do have a dual 31 channel peavey eq... but it is not hooked up... i know there are ways to notch out eq to eliminate feedback... but i don't really know where to start with that...right now i'm not eq-ing the FOH or monitor mix.

any help would be much appreciated.

[Tim McCulloch]

Hello Xgui-

Ex-gui?  Go back to command-line computing?

I'l gonna be as gentle as I can with this....  DO A SEARCH OF THE ARCHIVES!!!

Look to the left hand frame.... See the two headers that say "PSW SEARCH" and "PSW RESOURCES"?  The "Search SR Forum" will take you back to April 2004.  The "LAB Archives" link will take you to a search of over 100,000 posts spanning 7 years.  Guess what?  The answers to your questions ARE IN THERE.  In 8 years, the answers haven't changed, only the questions come more frequently....

You should have HOURS of ready pleasure and we expect you to actually hook up your rig and try the suggestions you will find in the archived posts.

HINT:  After all your efforts, you may still find that the monitors aren't loud enough, lack clarity or presence, etc.  That means you either need better monitors with more power (and significantly more $$$) or get your players to TURN THEIR SHIT DOWN so the singers can hear themselves.  It's called "ensemble playing" and musicians have been doing it for a couple thousand years.  The subtle complexities of TURNING DOWN *may* be lost on your musicians, in which case you need to evaluate how much time and effort you wish to expend in their aide.

Happy reading.

Tim "do the Newbs know about the freakin' LAB Lounge?" Mc

[bo putnam]

xguitox wrote on Mon, 13 September 2004 06:39

i do have a dual 31 channel peavey eq... but it is not hooked up... i know there are ways to notch out eq to eliminate feedback... but i don't really know where to start with that...right now i'm not eq-ing the FOH or monitor mix.

 

TimMc gives good advice.  As well, you need to study on frequency response and learn to use that EQ.  Being able to identify troublesome frequencies is not a quick study, but it comes with practice and trying.  Once you learn how to use that EQ, you'll be stupified you let it sit idle.  

Go get yerself copies of:

Live Sound Reinforcement (1996-2004) by Stark http://www.amazon.com/exec/obidos/tg/detail/-/0918371074/qid =1083633091/sr=1-2/ref=sr_1_2__i2_xgl14/104-5323659-7279122? v=glance&s=books

Sound Reinforement Handbook (1989) by Yamaha Engineers, Davis and Jones http://www.amazon.com/exec/obidos/tg/detail/-/0881889008/qid =1083633091/sr=1-1/ref=sr_1_1__i1_xgl14/104-5323659-7279122? v=glance&s=books

[Dave Miranda]

The previous two posts have great advise.  If your console has a Hi Pass filter on each channel USE IT!!  You'll find it to be a huge help on vocals.  100-160Hz will stop the low end roll.  This is just a "Bandaid".  Before you try to illiminate symptoms, you need to solve the problem.  It sounds as if your rig is not configured to the best of it's ability.  Before you go spending more money, try to seek out an experienced engineer to come in an "tune" the P.A with the pieces you have and get a recomondation on what is needed to improve it.  

Dave Miranda

www.IntegratedSystemsSolutions.com

[Andy Peters]

xguitox wrote on Mon, 13 September 2004 06:39

i do have a dual 31 channel peavey eq... but it is not hooked up... i know there are ways to notch out eq to eliminate feedback... but i don't really know where to start with that...right now i'm not eq-ing the FOH or monitor mix.

I'll summarize the search that Tim McC recommended:

You need EQs.  You'll need one 31-band-er on each monitor mix and one on your main mix (or two, if in stereo).

Your search will turn up many ideas on "how to EQ."

good luck,

-a

[Karl Winkler]

The above advise is right on target (what else would you expect here at PSW LAB?). I just want to add that with the 31-band EQ (which is pretty much mandatory for running monitors), you'll want to learn out to "ring out" your system. Do a search on this term, and look in the books for it. But here are the basics:

1. Hook up the 31-band EQ between the monitor/aux output and the power amp to the monitor wedge. Set all the sliders at zero.

2. Turn up the send to monitor channel, with the mic live, and someone standing in front of it (ideally wearing earplugs...) and have them sing or act like they are singing or yelling into the mic.

3. At some point, you'll notice the first feedback frequency. Say it is at 250Hz - then turn DOWN the slider at or nearest to 250Hz until the ring stops.

4. Turn up that channel again, and most likely you'll get a different frequency to ring this time. Figure out what it is, and turn down that EQ slider until it stops.

5. Repeat for two or three more rounds of this.

6. Now, you should have quite a bit more gain on the monitor channel than you did before, but without the feedback. The true test of course is while the band is actually playing...

And this excercise really takes some practice and experience to perfect, but now you know the basics.

Karl Winkler
Lectrosonics, Inc.
http://www.lectrosonics.com

[Michael 'Bink' Knowles]

Certainly learn how to use your existing EQ. Certainly get the lads to turn down. First techie thing I would do is put one channel of your Peavey EQ to work on the front line of monitors and the other channel to work either on the drum monitor or on the mono house system, depending on which one is more problematic.

But you say you tried gates.

One thought that occured to me is that if you have gates you might also be compressing the vocals such that the volume comes WAY up when the singer stops singing. If that's true, then back off of your compression threshold and ratio to help cure the feedback problem. EQ by itself won't solve this kind of wrong adjustment.

-Bink

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