Need..helps, "Microphone Feedback"

[tehaka]

I have problem with "Microphone Feedback"

is anyone have schematic/circuits like "ANTI FEEDBACK" can share with me...???
if not wrong "PHASE SHIFTER" circuit can solve my problem too, but I never built this before.....

Please...help me....
Thanks..you.

 

[Nigel Goodwin]

You need to be far more explicit about exactly what you're trying to do, you should prevent it at source rather than try and bodge a solution.

 

[audioguru]

Turn down the gain, eat and scream at the microphone and point the speaker away from the microphone.

The best method to eliminate acoustical feedback is to record your message then play it back after the microphone is turned off.

 

[mvs sarma]

choppers are used I remember. Practically same concept as What AG has advised.

 

[oldrocker]

A side chained parametric and or graphic EQ works if you know how to use it. Taking some of the high end down a bit sometimes helps like lowering treble controls. And of course keeping the mics in back of the speakers is the best way. A gated compressor is what I used when I did sound reinforcement for the Detroit / Windsor Jazz Society.(See the photo below)
I worked as a sound man not only in my own band but I did Jazz shows and rock and folk music shows and ran a small recording studio for a few years.

 

[tehaka]

Guys,
thanks about your avised, but if someone know about circuits or schematic
"anti Feedback" for microphone or Phase Shifter, tell me please..
I want to try to built this...
Like "FeedBack Destroyer-Behringer"

Thanks...guys.

 

[Nigel Goodwin]

Guys,
thanks about your avised, but if someone know about circuits or schematic
"anti Feedback" for microphone or Phase Shifter, tell me please..

You still haven't told us EXACTLY what you're trying to do and why, these are vital to give sensible answers.

I want to try to built this...
Like "FeedBack Destroyer-Behringer"

It's basically a DSP based automatic graphic equaliser, it detects the oscillation frequency and notches it out - it will do this for a specific number of frequencies before it gives up - it's debatable how much damage it does to the audio quality.

You aren't going to build one for anywhere near it's low cost, if you could at all - I'm currently sat about ten feet from one, but I've never had occasion to use it. Modern microphones are extremely good at avoiding feedback, which is why you need to give more details.

 

[tehaka]

thanks nigel...
I have toa mixer amplifier za-1121 (impedance amplifier) with output 100v and have 3 microphone input, 2 aux input.
I connected to the HORN Speaker 2 units, and the input 2 wireless mic (vhf) &
one Cable Microphone (dynamic).
The problem is when the wireless mic or cable microphone use for KOOR MUSIC, sound of KOOR Music is not enough loud...when i'm turn on the level of microphone, i've got feedback.
But when the microphone used for speech individual...the quality sound is good enough....
what's wrong...with my PA sound system ...I don't know why...
thanks...

 

[Nigel Goodwin]

What's the type of music got to do with anything?, you should be playing music via the Aux inputs.

 

[tehaka]

thanks nigel...
I have toa mixer amplifier za-1121 (impedance amplifier) with output 100v and have 3 microphone input, 2 aux input.
I connected to the HORN Speaker 2 units, and the input 2 wireless mic (vhf) &
one Cable Microphone (dynamic).
The problem is when the wireless mic or cable microphone use for choir song, sound of choir song not enough loud...when i'm turn on the level of microphone, i've got feedback.
But when the microphone used for speech individual...the quality sound is good enough....
what's wrong...with my PA sound system ...I don't know why...
thanks...

Sorry about my poor english language.

 

[audioguru]

I looked for "koor music" in Google but got no info about it.

Maybe the microphone for the choir is far from them and needs to have its gain set much higher than the close microphone used for speech.

The choir microphone should be directional (cardioid), pointed toward the choir but pointed away from speakers. There must not be a speaker near the choir microphone.