Whats the reason for noise in microphones?

[ykishore]

noise in microphones

when we use microphones usually we receive noise sometimes, in the sense we feel a high pitch disturbing sound coming out of it sometimes. This even happens only if we stand at particular places with it. What is the reason for that?

 

[Testone]

Re: noise in microphones

Are you using a wireless microphone?

 

[wwfieee]

Re: noise in microphones

probably it's positive feedback/osicallation/saturation.

one way to think about it is that you feed a wave to the speaker. the speaker spits out this wave. this wave goes back into the microphone. and speaker spits out a bigger wave, and on and on until the speaker saturates and high pitch sound.

 

[ykishore]

Re: noise in microphones

yes i'm using a wireless microphone. I can understand that the reason is due to positive feedback. But, why is this noise coming only in some specific places in our theatre and I want to find out will there be any effect of Air condictionars and other radiating equipment in the room.

 

[cedance]

Re: noise in microphones

yes i'm using a wireless microphone. I can understand that the reason is due to positive feedback. But, why is this noise coming only in some specific places in our theatre and I want to find out will there be any effect of Air condictionars and other radiating equipment in the room.

it happens if u are in level with the speaker withthe microphone.. then , the speaker picks up the noise and the amplifier runs into the oscillation mode due to the positive feedback! u can avoid it by standing at considerab;e distance and also at elevated positions compared to the speakers.. see ot it that u are not on the line of sight of the speakers.. more informal expalnation. Nm if it helped!

/cedance

 

[airman]

Re: noise in microphones

usually wireless microphone are more sensitive , so as "wwfieee" and "cedance" replayed the feedback takes place when the mike is in line of sight with the speaker , so you shoud make:

1) not be in line of sight with the speaker.
or
2)decrease the volume of the mike if it won't affect the coverage.
or
3)redistribute the speaker (or turn right or left) or up tilt it.

for more detail about speaker distribution you can surch for sound systems engineering sites.

with pleasure.

 

[big porkus]

Re: noise in microphones

Hi

I need to understand what kind of noise do you hear.
The type give to you informations about the kind of disturb.

"tac tac " sound, can be present if some high Power Transition (EMI emission)
is quite close. (ie. Power Amplifier with big fan cooler speed regulated ).
or a RF transmitter.
same for "crackle crackle"...

"fffiiiiiii" sound is a tipical loop effect (Larsen)
same as "wwwoooooo".

Ok i know this can be not so scientific but i hope that help you.

enjoy
;-))