# Best calibration file for EMM-6?



## LastButNotLeast (Sep 14, 2011)

I've decided to graduate from my analog RS meter to a microphone, probably the Dayton EMM-6 (unless enough people convince me to get the ECM 8000). I would appreciate it if someone would perform (or point me to the results of) a full-frequency sweep using:
1. the generic calibration file available here
2. the "individualized" calibration file available from the manufacturer's website, and
3. the customized calibration file provided by CSL.
Many thanks.
Michael


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## HifiZine (Feb 7, 2013)

#3 without a doubt.

This comparison may be of interest:

http://www.hifizine.com/2012/09/day...microphone-calibrated-by-cross-spectrum-labs/


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## LastButNotLeast (Sep 14, 2011)

That's (sort of) what I was looking for.
"Verifying that the calibration files do what you would expect is simple – just run two measurement sweeps, one with no calibration file selected, and one with a calibration file."
What I want is a comparison of that and the other two calibration files that are available.

Reading through the comments to the article, I came across this:
"I own a Dayton EMM 6 and use the calibration file supplied for my mic (serial number) via Dayton’s web site. Why is this not mentioned in the article?
Hi Olav, a combination of it not being a review of the stock EMM-6 and the time it would have taken to resolve my concerns about the Dayton cal file. I felt it wasn’t a productive path to pursue."

Gee, I would have thought it VERY productive. For my pedestrian system (compared to many, if not most, here), the other "calibrations" would probably be fine.
I compared the HTS file for my RS meter to that of the EMM-6. The typical correction for the EMM-6 is <1; most of the corrections for the RS meter were close to 10!

So I'm thinking either the stock or the average calibration will be "good enough" for my needs. But I'd like some proof of that.
Anyone?


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## HifiZine (Feb 7, 2013)

I guess I don't really understand. Nobody can prove to you what is good enough for your needs. The stock PE cal file has issues, you can search for more on that yourself. Wrt my review, I didn't see any point in figuring out WHY it has issues, I thought it sufficient (and enlightening) that the CSL cal file does very well for a small premium.

Please remember that the whole point of calibration is that it improves accuracy for a specific example of a microphone. The nature of the beast with acoustic measurement seems to be that every one is an "individual". Even if the generic "cal file" is accurate with one there is no guarantee that it will be accurate with another. If close enough is good enough, then get a stock mic and use the generic cal. If you need to know how the generic cal is likely to compare with hundreds of samples over several years then the best person to ask would probably be Herb from CSL... and if you're going to use his time with that then perhaps just order the calibrated mic from him? Seems only fair


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## LastButNotLeast (Sep 14, 2011)

I have searched, several days now, and haven't seen anything about "issues." But I'll keep looking.
"Small premium" is 50% more. That's what I'm trying to determine, since I avoided paying 50% more for my speakers (first generation Pioneers) and 50% for my sub (Klipsch) (and, frankly, 50% more for just about anything ). 
I'm certainly not going to bother Herb; even if I decide to buy the CSL calibrated mic, I'm just going to buy it.
I'm just really surprised I haven't seen this kind of comparison before.
Many thanks for your time and efforts.
Michael


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## HifiZine (Feb 7, 2013)

No worries Michael, it's late here now, I'll have a look to find some links tomorrow and if not will run some sweeps for you.


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## LastButNotLeast (Sep 14, 2011)

Thanks. That would be GREAT!
It's early here, so we'll cross paths "later."
:wave:


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## LastButNotLeast (Sep 14, 2011)

Found this discussion in the meantime:
http://techtalk.parts-express.com/s...te-are-Dayton-Audio-s-EMM-6-calibration-files

And this, directly from Herb:
"I believe that my data above about 5- kHz and below about 50 Hz are more accurate than the stock curves, but not by much anymore. If all you need is 20Hz - 20 kHz on-axis data, you're probably better off just buying the mic straight from PE and saving $30. If you need the value-added information I can provide, well, you can buy from me."

I'd still be interested in the experiment but, if it's a pain, you needn't bother.
Many thanks, Mate.


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## HifiZine (Feb 7, 2013)

Hi Michael, here is a comparison as requested. I did these "nearfield" to minimize room reflections. Cyan is the unmodified curve, blue is the CSL calibration, red is the PE calibration.

On a tweeter:

 

On a sub:



I guess it depends on what you want. If you are only doing sub measurement, then the PE cal is close enough I'd say. If you're planning to do full-range measurements or speaker testing, I wouldn't use the PE cal, it doesn't correct the mic response and it adds its own noise to the measurement.

Personally I'd spend the extra $30 and get something that will last a while.

This mic was purchased less than a year ago.


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## LastButNotLeast (Sep 14, 2011)

Fantastic. Many, many thanks.
Exactly what I needed.
And helpful to others with the same question, I'm sure.

Of course, a sample size >1 would always be better, right?
(hint, hint) ;-)


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## HifiZine (Feb 7, 2013)

Well, you've also got the comparisons that were in the link you found. Not sure what it is that you would expect to learn from more "samples"...


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## LastButNotLeast (Sep 14, 2011)

It would just be interesting to see how several compare, especially to the "average" calibration file.
I have enough to make MY decision; the rest is just curiosity.
Which, as you might imagine, has gotten me into trouble before.

Thanks, again.


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## HifiZine (Feb 7, 2013)

You did ask about the generic file, I forgot about that, sorry. There's a graph on the download page which shows how many samples of the mics vary, as of a while ago anyway:










My understanding is that the generic file is the average response. So you might get lucky and get one that's close, or you might not. Here are a couple of mics that I got last year from Herb in blue. The generic cal file is in green. So the ones I got were a fair way off the generic file. The red plot is the PE cal for the mic in the darker blue.


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