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Cross-Spectrum Microphone Calibration Service - USA

141667 Views 367 Replies 78 Participants Last post by  cichlids


We are happy to announce and recommend Cross-Spectrum Labs for microphone calibration in the U.S. ... particularly the Behringer ECM8000 and Galaxy CM-140. Of course, they will also calibrate other microphones as well.

Cross·Spectrum Labs
P.O. Box 90842
Springfield, MA 01139


I have personally spoken with Herb Singleton, founder of Cross-Spectrum, and he as agreed to calibrate these units 10Hz to 20KHz provided you specify you would like calibration to 10Hz. The charge is $55.00 and includes the cost of return shipping via USPS for customers in the continental United States..

Cross-Spectrum will use the pressure method to calibrate the low frequency response and the quasi-anechoic free-field on-axis method to calibrate the upper frequency response. The pressure method is one of the most accurate methods of measuring the frequency response of a microphone, however baffle diffraction must be accounted for when using this method. Generally mic manufacturers will provide the variance to offset the baffle diffraction. Unfortunately, Behringer nor Galaxy offers these variance corrections. Therefore, the free-field method of measuring the upper frequencies will be more accurate for these units. These combined calibration methods will give us the best calibration file for the ECM8000 and CM-140 mics. This is one of the first labs we have found that will calibrate the CM-140 SPL Meter microphone.

Cross-Spectrum also offers calibrated Behringer ECM-8000 microphones for sale. The cost is $100 + shipping. Please see their Behringer page for more information.

Herb will be joining us here at the Shack and has agreed to answer any questions anyone may have. Please check out their site before asking questions... you may very well find your answer. If you do not find the answer you are looking for, you may post a question here in this thread and Herb will do his best to get you an answer. Remember he is busy in the lab and does not monitor this forum 24/7, so please be patient... or you are more than happy to contact him by telephone (see their Contact Us page).

Remember, if you are wanting your mic calibrated to 10Hz, you must include a note requesting same, otherwise the calibration may only be to 20Hz.

We appreciate Herb's willingness to work with us in providing this service to our members here at the Shack.
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1 - 8 of 368 Posts
Re: Cross-Spectrum Microphone Calibration Service

Welcome Herb. It's great to have someone with your experience around. You'll most likely be hearing from me soon about a mic calibration.

Can you calibrate mics even lower than 10hz? Could you do 5 or even 3hz?
Re: Cross-Spectrum Microphone Calibration Service

Thanks for the detailed answers. I have an additional one. How much would a an ECM calibrated down to 5hz be with an additional 45 and 90 degree measurement? I'm most likely going to get on the waiting list for one.
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Re: Cross-Spectrum Microphone Calibration Service

Herb,

Do you know what the useable spl limit for the ECM8000 is? Seems to be about 120db or less?
Re: Cross-Spectrum Microphone Calibration Service

I've tested it up to 114 dB with no problems. When I get back from my trip I'll run some tests and see if I can find a definitive limit.
That'd be great. I seemed to have run into some output/ distortion limits with the mic while doing some close mic (2 or 3") low frequency tests. The apparent level that close up to the driver cone was somewhere between 120-125db.
Re: Cross-Spectrum Microphone Calibration Service

Thanks Herb.

Overall that doesn't seem too bad, but it looks like you want to keep things under 120db if you can for the ECM8000. Do you think that there would be a difference if the frequency was lower at like 32hz or 40hz?
Re: Cross-Spectrum Microphone Calibration Service

Thanks again for being so forthcoming with data and help with odd requests and questions. I think this distortion info will be very interesting for a lot of people.

I'm going to go ahead and guess that there will be noticeably higher distortion on the LF test. Won't the lower frequencies cause greater deflection of the mics diaghram for a set SPL?
Re: Cross-Spectrum Microphone Calibration Service

Well...That's eye opening. That could explain some of the things I was seeing. I can only assume that the distortion will get even higher the lower the frequencies get. Looks like you should keep things under 110db when using this mic to remain clean. Not that any one serious about high SPL measurements would be using an ECM8000 in the first place.

Do you think that the ECM will compress the signal somewhat above 120db?
Re: Cross-Spectrum Microphone Calibration Service

Good stuff. Looks like the unit to unit variation has a range of around 6db or more on both ends of the spectrum.:gulp:. Calibrating your ECM or buying one with the calibration done already seems like a necessary evil.
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