# Use 1/3 octave or Narrowband Cal File



## Guest (Oct 13, 2008)

Hello everybody.
Two weeks ago I bought a ecm8000. I compared this mic to a B&K omni, and a clio mic on a clio system.
I used the cal file posted on this Forum. I noticed a large error in the 6 to 10K range with the ecm8000.
( 3 db or more boost on ecm8000) I tried another cal file posted on a different forum, better but still large error. Then I purchased a calibrated ecm8000 here:

cross spectrum labs
can't post link as i am new to forum

The cal file looks like it will correct perfectly for the errors I was seeing.
My question is this. I was sent 2 calibration files. 1/3 octave and narrow band which has 1300 points.
Both load in REQ. Will req bog down with the large file or is it no problem?
Will it interpolate the points in between if I run a 1/6th octave test using a 1/3 octave cal file.
Last note . I do not think the cal file posted here is much use. I bought two mics, they seem close
to each other but far from cal file posted here.
Thank you
Brad


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## JohnM (Apr 11, 2006)

Brad,

You can load either file, makes no difference to REW. It will interpolate between correction points. I'd use the narrow band file personally. Might be interesting to post your cal file for comparison purposes.


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## brucek (Apr 11, 2006)

> Both load in REQ. Will req bog down with the large file or is it no problem?


Should be no problem, as the cal files are applied post measure to the impulse response to produce the frequency response graph, waterfall etc.



> Will it interpolate the points in between if I run a 1/6th octave test using a 1/3 octave cal file.


Yes.



> I do not think the cal file posted here is much use.


Perhaps not for yourself, but for home use in setting up an equalizer and room treatments it's perfectly adequate. No generic cal file is accurate, except for the microphone it was created for. We had an ECM8000 mic professionally calibrated and then compared it against two others and they all measured the same. We offer the cal file for free for those who want a relatively decent correction to set up low frequency parametric equalizers and test room treatment. If it's of no use to you, don't use it. 

brucek


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## Guest (Oct 13, 2008)

John
Thank you for the reply, and again great Job. got side tracked but I will donate this week.
I will also try to post the data later this week.
Brad


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