Dayton Audio EMM-6 as good as UMIK-1 for someone who already has an audio interface?

[bgravato]

I'd guess that is expected and makes some sense, because low frequencies are much less directional than high freqs.
So the lower the freq the less the direction of the mic should be relevant and the opposite for higher freqs.

 

[Blumlein 88]

Thank you for the clarification. No, I checked my 90 degrees cal file and I meant to type 0.6 dB. I have attached it for you to have a look.

Okay so I see where we are looking at this differently. I am taking my 0 degree cal numbers in a spreadsheet. Then put the 90 degree cal numbers into it. Then subtract one from the other. This gives you the adjustment difference between 0 and 90 degree. Now I can compare your 90 degree to my 90 degree, but not how it differs from your 0 degree unless you supply that.

What I found with a few other cal files is that difference in 90 degree versus 0 degree was the same for all the cals I checked. The basic 0 degree correction varied between different microphones, but the difference in 0 and 90 degree did not. Does that make sense or am I being unclear still?

 

[Blumlein 88]

Okay I'm attaching a zip file with both a txt file and an older xls format for use in a spreadsheet. I think it will make clear what I'm doing. The third column on the right hand side is the difference in 0 degrees vs 90 degrees. I had the same exact result with 4 different Umik 1 calibration files. I think that is what they mean by auto generated.

So someone with a Dayton EMM 6 could probably use that third column with their 0 degree cal file and create a 90 degree file which would be pretty close or at least much closer than not having one. Because both microphones are 6 mm diaphragms. While it may not be perfect the slightly directional nature of that 6 mm size is responsible for most of this. All you need is my 3rd column and add it to the 0 degree calibration at each frequency. Of course I don't know if the Dayton uses the same frequencies so one might have to adjust for that.

 

[Sam Ash]

I'd guess that is expected and makes some sense, because low frequencies are much less directional than high freqs.
So the lower the freq the less the direction of the mic should be relevant and the opposite for higher freqs.

That does make sense, although it would be nice to be able to self calibrate a Dayton EMM-6 mic against a UMIK-1 with a cal file. I'm trying to figure out how to do this in REW, I'm sure it's possible.

 

[Sam Ash]

Okay so I see where we are looking at this differently. I am taking my 0 degree cal numbers in a spreadsheet. Then put the 90 degree cal numbers into it. Then subtract one from the other. This gives you the adjustment difference between 0 and 90 degree. Now I can compare your 90 degree to my 90 degree, but not how it differs from your 0 degree unless you supply that.

What I found with a few other cal files is that difference in 90 degree versus 0 degree was the same for all the cals I checked. The basic 0 degree correction varied between different microphones, but the difference in 0 and 90 degree did not. Does that make sense or am I being unclear still?

That definitely makes sense. The 90 degree cal file is derived from the 0 degree cal file by fixed amounts. Here are my 0 degree and 90 degree cal files for your reference.

 

[Sam Ash]

@Blumlein 88 - I opened the text and excel file that you provided but the 3rd column on the right under the Auto generated section are all 0.0000. I have attached a screen shot for your reference.

 

[Blumlein 88]

That does make sense, although it would be nice to be able to self calibrate a Dayton EMM-6 mic against a UMIK-1 with a cal file. I'm trying to figure out how to do this in REW, I'm sure it's possible.

Do a measurement of any speaker with your Umik using the cal file. Then do one of the same speaker using the Dayton from as close to the same location as possible.

Then open both measurements together in REW. Open controls. Choose align SPL which will more or less match levels in the graph. Then under Trace Arithmetic select divide A/B. You have to select B as one and A as one. Down at the bottom will be a difference graph somewhere close to 0 db on the chart.

 

[staticV3]

Do a measurement of any speaker with your Umik using the cal file. Then do one of the same speaker using the Dayton from as close to the same location as possible.

Instead of trying to match the location, just do a measurement with the moving microphone method. Much more repeatable.

 

[Blumlein 88]

@Blumlein 88 - I opened the text and excel file that you provided but the 3rd column on the right under the Auto generated section are all 0.0000. I have attached a screen shot for your reference.

Actually I did send the correct file. You didn't look down far enough. Both calibrations are the same until past the 600 hz mark on line 339.

 

[Blumlein 88]

Instead of trying to match the location, just do a measurement with the moving microphone method. Much more repeatable.

Not sure if that would work for this as you'd need to move it the same I think. Interesting idea, maybe I'll try it and see one afternoon.

 

[dominikz]

If someone with a set of cal files for a Cross Spectrum Dayton would share them, you could make even better off axis adjustments to the basic on axis file Dayton provides.

Here's how my Cross-Spectrum Labs calibrated Dayton EMM6 calibration curves look:

The manufacturer-provided calibration file doesn't seem reliable unfortunately; here's how the stock calibration curve compares to the Cross-Spectrum one for my mic:

 

[Blumlein 88]

Here's how my Cross-Spectrum Labs calibrated Dayton EMM6 calibration curves look:

The manufacturer-provided calibration file doesn't seem reliable unfortunately; here's how the stock calibration curve compares to the Cross-Spectrum one for my mic:

Less than a half db difference than the 90 degree vs 0 correction up around 19 and 20 khz vs the Umik correction. Was the manufacturer file the one for the same microphone from Cross Spectrum labs? Pretty big difference if so.

 

[Blumlein 88]

Okay here is a zipped Excel file showing the difference in the two calibrations for your Umik and mine. You'll see the difference is the same while the calibration levels vary between the two microphones.

 

[dominikz]

Was the manufacturer file the one for the same microphone from Cross Spectrum labs? Pretty big difference if so.

Yes, retrieved from a Dayton web service based on the mic serial number. I too was surprised to see how different it is - looks almost randomly generated.

 

[Sam Ash]

Not sure if that would work for this as you'd need to move it the same I think. Interesting idea, maybe I'll try it and see one afternoon.

You are right indeed, thanks for the clarification.

 

[Sam Ash]

Do a measurement of any speaker with your Umik using the cal file. Then do one of the same speaker using the Dayton from as close to the same location as possible.

Then open both measurements together in REW. Open controls. Choose align SPL which will more or less match levels in the graph. Then under Trace Arithmetic select divide A/B. You have to select B as one and A as one. Down at the bottom will be a difference graph somewhere close to 0 db on the chart.

Using a mic stand, I could probably position both Mics at exactly the same location. Once I get the difference graph, is it possible to use it as a calibration offset for the Dayton Mic or generate a calibration text file for use within REW?

 

[Sam Ash]

Okay here is a zipped Excel file showing the difference in the two calibrations for your Umik and mine. You'll see the difference is the same while the calibration levels vary between the two microphones.

True and very interesting.

 

[Sam Ash]

Here is some interesting information that I came across:-

Dayton and Behringer Calibration Mics

 

[voltronic]

Here is some interesting information that I came across:-

Dayton and Behringer Calibration Mics

That's not surprising. Even if the housing wasn't so similar, there are not that many mic companies who make their own capsules. That's true for any type of microphones. Two companies I know of that make high-end measurement capsules are Brüel & Kjaer and Microtech Gefell, and those are orders of magnitude more expensive than the mics we're discussing.

I have read reports recently about another manufacturer of expensive and well-regarded measurement mics who does not manufacture their own capsules, but purchases them wholesale like the cheap mic companies do. I'm not going to say who it is until I can verify those claims, because it would be a bit scandalous given their prices.

 

[Sam Ash]

Do a measurement of any speaker with your Umik using the cal file. Then do one of the same speaker using the Dayton from as close to the same location as possible.

Then open both measurements together in REW. Open controls. Choose align SPL which will more or less match levels in the graph. Then under Trace Arithmetic select divide A/B. You have to select B as one and A as one. Down at the bottom will be a difference graph somewhere close to 0 db on the chart.

@Blumlein 88 - can you kindly elaborate on this procedure. How does one create a cal file that can be used with the newly calibrated mic?