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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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WAIT.
They sell out each run quickly. You'll thank yourself.
Thanks, I'll keep checking
Hello everyone,
this question is for Herb, or anyone really who knows the answer. I purchased a calibrated UMM6 from cross spectrum about 6 months ago or so and have been extremely pleased with the mic and service recieved from Herb/Cross Spectrum Labs. I use my UMM6 roughly 2-3 times a week at work (Custom car audio installation), and every now and then i bring it home with me on my days off to experiment with test and measurement, and to learn Smaart 7, (upgraded from 6, finally!!). Regarding transporting the mic, i often toss it in the side pouch of my laptop instead of keeping it in the case. How does the way we handle and transport the mic affect its accuracy and if it is damaged will it be grossly inaccurate or can it be thrown off by a tiny percent?
Hey all,

It's been far too long since I've posted here, I can't believe how fast time flies.

First off, Happy New Year to all. Thanks for all of the support, and please keep those discount requests coming!

Second: I just wanted to let folks know that we're selling the MiniDSP 2x4 digital signal processor unit. And as with the other products we sell, you HTS folks can wet your beaks a little - leave your HTS username in the "Instructions to Merchant" field and we'll refund you $5.

We're starting slow right now just to make sure we can handle the support aspect of selling these so we'll likely run out of units quickly. Once we're comfortable, we'll start selling them in volumes.

Carry on!
Question about the sensitivity information being missing from the CSL umik 1 calibration file.

I have created a collated file that has both the miniDSP and CSL data
> the miniDSP has sensitivity information ( I really like not having to calibrate the SPL with my Galaxy 140 every time I plug in the mic)
> the CSL has better low/high frequency range and also is accurate for my specific mic

So the file i created has all data from both files interwoven within. Using this file REW does not require to calibrate every time I plug in the mic for accurate SPL readings.

Concerns:

There is no parsing errors from the new file when REW starts but I wonder if some lines are just being looked passed with "False-Negative" results

Questions:

A. What does the second column of data actually represent in both these calibration files? Because if it is sensitivity data then both files have this data and why then would the CSL cal. file not then allow REW to avoid this step thus requiring me to use my SPL meter.

B. What does the third column of data represent in the CSL calibration file? This column only has zero's and it is not present in the miniDSP file.

C. How does REW parse the data in this calibration file? Does it consider any "white-space" to be the same as "tab" and the same as "Line Return" as being next data to process?

Here attached is a sample of screenshots of the file I have created.
> The CSL file are the lines that have the third column of zeros
> The miniDSP file only has two columns of data


!.. [edit] ..! ... I obtained some answers :nerd:

  • The first line of the miniDSP calibration file is the actual sensitivity information.
  • The second column in both CSL/miniDSP files is level difference in dB from the reference mic
  • The third column in the CSL file is the phase used

Attachments

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W3Rman:

A: the second column (of both mic files) is the relative response of microphone, in dB relative to 0 dB at 1,000 Hz. It is *not* the mic sensitivity. To obtain the sensitivity at each frequency, the relative response needs to be scaled by the sensitivity.

B: the third column is there because some programs expect to see a column for phase data and will report an error if provided with only two columns of data. Because we don't measure phase for the microphones, we just report "0" for the phase data.

C: I'll let John handle the specifics wrt to REW, but I think (again, confirm with John) that REW treats tabs and spaces as an identical delimiter and treats CR/LF (in various combos) as end-of-line.

Also (for those that may not be aware): CSL calibration files generated after January 2016 for UMIK-1 and UMM-6 mics include the *factory* sensitivity data in a separate set of calibration files in a "REW" directory on the USB stick. Again, these are the factory values, CSL does not vouch for these figures and does not support these values. They are there because a lot of people want it.
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^ ^
:jiggy:

Thanks for clearing these details up with me
Sorry for the thread revive, but I'm curious if the calibration service is still available? I have a current UMIK-1 and would like to send it in for calibration. Am I still able to do so?
Hope this makes sense fingers crossed??? I would like to get my Umik-1 mic re calibrated. I sent Herb some messages he answered some but not all, for those that have one of his mics if you are using it along with REW will you get a sweep that goes below 10hz?? The mic I bought along w/ the bal. minidsp seems to hit a wall at 10hz.I would like to see if my subs will go lower.
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