Does anyone know about a company och individual preferbly in sweden, second... europe who can preform a reliable calibration file for mics? Without litterally trashing the wallet? 🙂
//jonas
//jonas
Send me a PM and we can discuss. I'm in Estonia - so close enough probably and have done this time to time and have the tools and methods 😉
I can do it (see here). My references are Beyer and Behringer mics with third-party calibrations and an ISEMCON with manufacturer calibration.
Before even thinking about doing a DIY mic calibration, read:
How Earthworks Measures Microphones
By Alex Khenkin, Director of Engineering, Earthworks
How to measure microphones and the implications relating to measuring loudspeakers.
http://earthworksaudio.com/wp-content/uploads/2012/07/how-earthworks-measures-mics.pdf
How Earthworks Measures Microphones
By Alex Khenkin, Director of Engineering, Earthworks
How to measure microphones and the implications relating to measuring loudspeakers.
http://earthworksaudio.com/wp-content/uploads/2012/07/how-earthworks-measures-mics.pdf
That's an attempt to achieve "ab-initio" calibration. That's quite different from the conventional method of referencing the DUT to a mic with known response.
A 'from the beginning' calibration?
In the home theater forums, I have read many posts about DIY calibrations and most get it wrong.
Once again:
Before even thinking about doing a DIY mic calibration, read the Earthworks paper!
In the home theater forums, I have read many posts about DIY calibrations and most get it wrong.
Once again:
Before even thinking about doing a DIY mic calibration, read the Earthworks paper!
I guess the OP wants to know the transfer function of his microphone ("frequency response + sensitivity"). You don't need the Earthworks Big Bang method for that.
Earthworks microphone super sience in all glory but that is not what i search for.. all i really want is, as already spoken, transfer function of my mic.
Yes, you can recreate the Earthworks technique with a barbecue grill starter the maths for the response corrections are readily available on the web. You can get better than 1dB match to a B&K lab calibration. For sensitivity you can build a piston chamber with a small computer speaker and a slice of thick mailing tube and use a medical grade strain gauge pressure transducer in gauge mode to sample the internal pressure. They are laser trimmed to 1% (.1dB) absolute sensitivity and respond from DC to about 3500Hz. A small chamber gets around 300Hz resonance with a side benefit that because the resonant frequency is not geometric the harmonics of the excitation are rejected and you get the harmonic distortion of the mic. It's a fun experiment, you can get 150dB SPL internal to the chamber but back radiation of the speaker is not very loud.
I do have to say in general for DIY use the calibration problem is probably a bit overstated.
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That's an interesting idea. Can you point me to a suitable pressure transducer that doesen't cost an arm and a leg?
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