# DEQ2496 and calibrated mics



## Anechoic (Jan 16, 2009)

I'm trying to help out a customer, and since I'm a little out of my depth I figured I'd ask for help.

A customer bought a microphone expecting that the mic had been physically modified to produce a flat response rather than relying on a correction curve to flatten the response. The issue is that he wants to use the mic with a Behringer DEQ2496 which doesn't accept correction files and he's wondering if there is a way to correct the response for the mic.

Unfortunately my experience with the DEQ2496 is very limited. I know the recommended method is to use the DEQ with a seperate mic & power supply, but I was wondering if anyone had any suggestions for using the unit + calibrated mic on their own.

After reviewing the manual it seems to me that a user could set the "AUTO EQ function (AEQ)" (page 15, Section 3.8.1) to an inverse of the mic cal curve and that would have the effect of generating a "flat" equalization curve. Since I provide 1/3 octave band data, the user could enter the data manually (but I'm sure it would be a pain, hopefully the data could be stored in one on the presets).

Could anyone who has more experience with the DEQ2496 tell me if I'm barking up the wrong tree here? If the mic isn't a good fit, than so be it, but I'd like to try and make this work for the customer.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Hi Anechoic,

For starters, no power supply is needed for the DEQ. It has phantom power built in.

As you may know, before the advent of software measurement, hardware RTAs were all internally calibrated for the measurement mic they came with, _individually_, before they left the factory.

The DEQ comes with no “calibrated” mic, so the accuracy of any measurements it takes is solely dependant on the response of the mic itself. Naturally, Behringer recommends the ECM-8000, but as you know there is little consistency in that mic from one sample to the next. I guess your client knows this is the obstacle he faces.

Frankly I can’t decipher the mumbo-jumbo in the DEQ manual for Page 3 of the auto EQ function to determine if what you’re proposing will work. Obviously your client needs to have you do a calibration of his mic, even if it has been physically modified, to know for sure what its response really is. That way, even if the file can’t be “loaded” into the DEQ, it would be simple to adjust the DEQ after-the-fact to compensate for the mic (assuming you can do that without blowing out the Auto EQ settings). For instance, the mic you calibrated for me, a simple 1-octave filter @ ~8 kHz cut ~4 dB would be adequate to “render” the mic’s response as flat.

Regards,
Wayne


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## Anechoic (Jan 16, 2009)

Thanks for the feedback Wayne.


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## spinnaker (Aug 6, 2011)

So, I measured with the Behringer and adjusted the target curve with the reverse values from the calibration sheet.

I also did a separate low frequencies calibration that I edited into the final setup.

I wonder if I really need REW now. The results seem pretty good, as if I bypass the EQ I can notice the harsh unprocessed sound.

I'm using the UltraCurve purely in the digital domain.

I have a preset where I store the adjusted target curve, that I load before running the RTA.


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