Microphone noise ....

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

gary o

Well-known member
Joined
Dec 28, 2004
Messages
1,531
Location
uk
How can I neasure noise of a mic ....... I have no scope or proper gear .... at the moment I just record an open mic and compare to other mics I have ..... I have 3 home made mics Im concerned with a Mk47 kit Violet Vin67 head (favorite capsule I own) a C12 elam kinda hybrid with Tim cambel capsule& a Oktava 012 circuit RK47 capsule least favorite capsule I own ...... 47 mic has most noise, C12 next and then solid state 012 is quietest

Up to now I have been concerntrating on the sound of the mics but now I would like to get them as quiet as possible ..... I might put C12 guts in the Skylar 47 body I have.... as doesnt seem to be much difference in sound other than the U47 is noisier, will try couple more tube first tho..

thanks
 
Of course without any measuring equipment it will be very difficult to measure the noise...
To start with, it is very important to normalize the output levels of the microphones.
If one microphone produces 10 mV at a certain sound pressure level, another microphone might produce 5 mV or 20 mV.
When the noise level is the same, the difference in signal to noise ratio is already 6 dB!
So what you have to do is to generate a well defined sound presure level (maybe a test tone generated by a PC program and played through a speaker), and call this 0 dB.
Then you could record 'silence' (maybe even pack the microphone under test in a blanket, to avoid further ambient noise).
A lot of PC programs let you measure the noise level (or sound level), sometimes even the "A weighted" noise level.
This will give you an indication, although maybe not the most scientific way...
But what counts is: what is the noise compared to the wanted signal.
 
Thanks RuudNL thats similar to how I have been doing it but without a PC program , I was just using ears & looking at large level meters in my DAW.... I can at least hear the difference between mics I have made or own.
 
Isn't the ear the most important piece of measuring equipment we have?!  :)
(If you don't hear it, it is not there so there is nothing to worry about...)
 

Latest posts

Back
Top