# Behringer ECM800 and its SPL calibration



## AndreaT (Jan 17, 2012)

Hello Folks,

anybody of you has details about the SPL voltage response of a typical ECM 8000 microphone?

I am looking for the ECM 8000 output voltage (at the XLR connector) response vs. SPL input at 1 meter.

In other words, I would like to use the standard ECM 8000 as an SPL meter too.

I don't need any high accuracy, a +/- 3dB accuracy will be even better than needed.

Many thanks in advance to anybody will help me.
Regards,
Andrea.


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## JohnM (Apr 11, 2006)

A bit of googling turns up that the '-60 dB' figure on the ECM datasheet should read -60 dBV/uBar = 10 mV/Pa. An example cal sheet for one had 8.2 mV/Pa.


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## AndreaT (Jan 17, 2012)

Dear John,

me too did some calculation and from the Standard definition I should get-out the following:
ECM 8000 at 94 dB-SPL @ 1kHz sinusoidal tone shall ouput 1 mV signal.
And at 75 dB-SPL it shalls output 0.112 mV signal

Does this match what you said?
Or, do you see differences?

Thanks a lot for your help!
Kind regards,
Andrea


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## JohnM (Apr 11, 2006)

75 dB would be 0.112 Pa so I would expect the output at 75dB to be around 1.12 mV at the nominal 10 mV/Pa sensitivity.


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## AndreaT (Jan 17, 2012)

Hello John, I am not so sure you are right. I contacted Behringer (you know it is a German company and they use the formula "Reference: 94 dB-SPL ≡ 1 pascal") and they confirmed me my calculation to be correct.
So, unless the Behringer support was completely sleeping, I am expecting they checked my calculation:
- if the ECM 8000 output 1 mV at 94 dB-SPL
- it should output 19 dB below at 75 dB-SPL, so, 0.112 mV (= 112 uV).

Does it work for you too?
Thanks and regards,
Andrea


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## JohnM (Apr 11, 2006)

94 dB SPL is 1 Pa, but the stated nominal sensitivity of the ECM8000 is *10* mV/Pa, which would mean 10 mV at 94 dB and 1.12 mV at 75dB. This sample calibration sheet from IBF Acoustic shows 8.2 mV/Pa sensitivity.


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## AndreaT (Jan 17, 2012)

Thank you John, so the Behringer support told me the false.
Regards, Andrea


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