Live setup feedback

[Musart]

Hi All,

I play in a band and we play live in a private party once a year. Each time i get this feedback problem with microphone.

The setup is :

- Sequenced drum and keyboard.

- Two accoustic guitars, which the holes are blocked with a rubber to prevent feedback.

- An electric guitar with a Line6 Pod.

- 3 microphones for vocal. (mostly SM-58)

- P.A and 1 monitor on the stage.

Do you have any hints and tips to avoid microphone feedback ?
I Know this is a matter of mic placement, volume.

But I heard that you can EQ for solving this problem

Thank you

 

[muttley]

Are the house speakers in front so that your are behind them when you are playing? Meaning the stage is deep enough?
Whats behind you? A live( reverbiant) wall? Or carpeting/drapes?
Are the mic's butts pointed to the monitors? Whats the volume level on stage?
The reason I ask is the E/Q thing is not always the answer, if the stage is real small/shallow, the back wall is real close, the feed back may always be a problem. Sometimes the house speakers get placed behind you and that will always cause a feedback to occur no matter what the volume.
If you don't mind, shoot more details this way.



da MUTT

 

[Musart]

Are the house speakers in front so that your are behind them when you are playing? Meaning the stage is deep enough?
Whats behind you? A live( reverbiant) wall? Or carpeting/drapes?
Are the mic's butts pointed to the monitors? Whats the volume level on stage?
The reason I ask is the E/Q thing is not always the answer, if the stage is real small/shallow, the back wall is real close, the feed back may always be a problem. Sometimes the house speakers get placed behind you and that will always cause a feedback to occur no matter what the volume.
If you don't mind, shoot more details this way.



da MUTT

Thanks for helping

We (and the mics) are behind the house speakers and the monitor speaker. Mics are at 2 or 3 feet behind them. Monitor is in the middle and the house speaker at at 10 or 12 feet away of each other.

There's a wall behind us at around 6 feet of the microphones.

The ceiling is at 8 or 9 feet above us.

Maybe the mic's butts are pointing at the monitor (if you mean by butt : where the wire is plugged into the mics ?).

What else ... It's difficult to tell the volume in dB. I tend to make the vocals predomiment. A little increase in the mids and high frequencies. Maybe 1 or 2 dB at 1khz and 12khz.

I appreciate your help.

 

[DJL]

Two accoustic guitars, which the holes are blocked with a rubber to prevent feedback.

What..... are you saying you've plugged the "sound holes" on your acoustic guitars with rubber?

 

[muttley]

That wall 6' away from the mics would be where I would start, Can that wall be treated with some absorbing material, even if you had to provide it? Or can your whole setup be moved 3 or 4 feet away from wall?
Mic butt is the connector side.

The boost you have on mics sounds reasonable, Whats you post E/Q settings? The E/Q between the mixer/amp.
The S/M 58 does have quite the boost on the 10k region......
maybe a little pulling back on this....???


da MUTT

 

[Doug Quance]

Is the feedback coming from the mics or the guitars?

Is the feedback a high squeal, or is it a low rumble?

 

[Musart]

Re: Re: Live setup feedback

What..... are you saying you've plugged the "sound holes" on your acoustic guitars with rubber?

This is a rubber cap you put on the guitar hole to cover it. So there's is no chance of feedback.

 

[DJL]

Re: Re: Re: Live setup feedback

This is a rubber cap you put on the guitar hole to cover it. So there's is no chance of feedback.

I've never seen such a thing before.... I would think it would also kill the sound..... who makes that rubber cap? Thanks

 

[sae]

First off you have to find out if the feedback is coming from the monitors or the mains. Once you find that out set all your eq settings to unity. turn up the gains on your mics until it's ALMOST about to feedback. solo the mics until you find the one(s) that are feeding back. Then turn down the frequencies that are causing the feedback. Problem solved.

Note: The bigger your eq the better this works.

 

[Musart]

Re: Re: Re: Re: Live setup feedback

I've never seen such a thing before.... I would think it would also kill the sound..... who makes that rubber cap? Thanks

Not if you have a pickup under under the saddle. My Guild does have this. So i plug it direct on the mixer and it sound great for live application. I don't mic the guitar when i play live

 

[Musart]

Is the feedback coming from the mics or the guitars?

Is the feedback a high squeal, or is it a low rumble?

It comes from the mics because the guitars are direct plug, that's why i put a rubber cap (which is made and sold for this application)

I would say most of the time low rumble.

Thanks

 

[Musart]

First off you have to find out if the feedback is coming from the monitors or the mains. Once you find that out set all your eq settings to unity. turn up the gains on your mics until it's ALMOST about to feedback. solo the mics until you find the one(s) that are feeding back. Then turn down the frequencies that are causing the feedback. Problem solved.

Note: The bigger your eq the better this works.

If i remember last year, i would say it come from the monitor. I have a set-up to do on Saturday i will try this.

Thank you

I will let you know

 

[Musart]

That wall 6' away from the mics would be where I would start, Can that wall be treated with some absorbing material, even if you had to provide it? Or can your whole setup be moved 3 or 4 feet away from wall?
Mic butt is the connector side.

The boost you have on mics sounds reasonable, Whats you post E/Q settings? The E/Q between the mixer/amp.
The S/M 58 does have quite the boost on the 10k region......
maybe a little pulling back on this....???


da MUTT

No, i can not treat the walls, it's a rented place.
I've never post EQ. Don't ask me why. Maybe i should try a bit.

I should try the 10k region for SM58.

I'll try this too on Saturday.

Thanks for helping !

 

[Musart]

Re: Re: Re: Re: Live setup feedback

I've never seen such a thing before.... I would think it would also kill the sound..... who makes that rubber cap? Thanks

See here :

http://proaudiomusic.com/accessories/feedback-buster.htm

 

[DJL]

Re: Re: Re: Re: Re: Live setup feedback

Not if you have a pickup under under the saddle. My Guild does have this. So i plug it direct on the mixer and it sound great for live application. I don't mic the guitar when i play live

Well, your not really going to get any feedback from the sound hole if your not miking the guitar anyways are you? Who makes that rubber sound hole cap? Thanks

 

[Musart]

Re: Re: Re: Re: Re: Re: Live setup feedback

Well, your not really going to get any feedback from the sound hole if your not miking the guitar anyways are you? Who makes that rubber sound hole cap? Thanks

I thought the same thing until i tried it. It makes a big difference. Here is some theory :

http://www.soundchick.net/feedback.html


And a supplier:

http://proaudiomusic.com/accessories/feedback-buster.htm

 

[DJL]

Ok........ now just to make darn sure that the feedback isn't coming from any of the instrements..... turn off ALL the instruments. In fact..... turn everything OFF.

Now..... ONLY turn on the mains (and mic's if they have switches) . Are you getting ANY feedback from the mains?

If there is feedback...... tell me so?

If there is NO feedback at this point...... turn OFF the mains.

Now, ONLY turn on the monitors (and mic's again)....... is there ANY feedback now?

If there is feedback tell me so?

We'll stop here to find out the about above results.

 

[wilkee]

An acoustic guitar with pick-ups does feed back if the levels are high enough as they use a transducer to pick up the vibrations from the bridge.

This basically turns the whole guitar into a giant Mic. Which is why the taps on the guitar body come thru so clearly.

From what I have read in this thread unless you are playing at very loud levels you should not be having feedback problems.

Try playing without the foldback as this is always the first place to start.