UMIK-1 or any USB MIC unsuitable for timing measurements?

[Emlin]

So you think they go to the trouble of batch testing, and then scramble the SN's randomly so people don't know it.

BTW, how do you batch test mics like this? You stick ten up and do it all at once and average. You test 10 one at a time and average the results for that group. You do realize since they measured it would be easier to just use the results for each mic. The batch testing idea would be more trouble to them. If I'm guessing, I'd guess CSL has the more accurate calibration, but I don't see much reason to think these others are not individually done.

You take a few mics at random and average the results.

 

[dcibel]

If one thinks the Dayton is too bumpy, using 1/6 octave smoothing will take care of it.

1/6oct smoothing isn't going to do you any favours.

 

[levimax]

So you think they go to the trouble of batch testing, and then scramble the SN's randomly so people don't know it.

BTW, how do you batch test mics like this? You stick ten up and do it all at once and average. You test 10 one at a time and average the results for that group. You do realize since they measured it would be easier to just use the results for each mic. The batch testing idea would be more trouble to them. If I'm guessing, I'd guess CSL has the more accurate calibration, but I don't see much reason to think these others are not individually done.

A lot of manufacturing is done in "batches" where the raw materials for a batch comes in and a batch of product is produced. In this case rather than test every Mic they would, using some statistical analysis based on previous batches, randomly pick a number of Mics from the beginning, middle, and end of the run and test them and then assume a "normal distribution" (assuming they weren't seeing "trends" in the run) come up with a "average" calibration file for that batch and then make that file available for download for all the serial numbers in that batch

 

[DVDdoug]

A lot of manufacturing is done in "batches" where the raw materials for a batch comes in and a batch of product is produced. In this case rather than test every Mic they would, using some statistical analysis based on previous batches, randomly pick a number of Mics from the beginning, middle, and end of the run and test them and then assume a "normal distribution" (assuming they weren't seeing "trends" in the run) come up with a "average" calibration file for that batch and then make that file available for download for all the serial numbers in that batch.

That's perfectly valid for a "recording mic". They might not even measure the frequency response of every mic. If you buy a Shure mic it's not going to exactly-match the published frequency response.

But IMO that would be dishonest for a calibration mic with a file tied to the serial number or for a calibration mic with a specification. Anything used for measurement should be individually verified.

If you're paranoid you can send your mic to an independent calibration lab. I think that costs around $100 USD, plus shipping. If you are doing "serious work" your equipment should usually be periodically calibrated. And there are always tolerances.

 

[Blumlein 88]

You take a few mics at random and average the results.

Then why would each cal file differ? What you are describing is extra bother for them.

 

[Emlin]

Then why would each cal file differ? What you are describing is extra bother for them.

You have no proof that they all do differ, as I explained above. I honestly don't know why you are getting so aerated about this.

 

[Blumlein 88]

I guess the batch testing meme is strong. Beats me why? Carry on.

 

[Blumlein 88]

You have no proof that they all do differ, as I explained above. I honestly don't know why you are getting so aerated about this.

Find two files that are the same.

 

[Emlin]

Find two files that are the same.

Please do not make unreasonable demands, it is so unbecoming.

 

[Blumlein 88]

That's perfectly valid for a "recording mic". They might not even measure the frequency response of every mic. If you buy a Shure mic it's not going to exactly-match the published frequency response.

But IMO that would be dishonest for a calibration mic with a file tied to the serial number or for a calibration mic with a specification. Anything used for measurement should be individually verified.

If you're paranoid you can send your mic to an independent calibration lab. I think that costs around $100 USD, plus shipping. If you are doing "serious work" your equipment should usually be periodically calibrated. And there are always tolerances.

I doubt Shure measures every mic. Maybe a sampling for QC. They do make them consistently. Here are three KSM 32's. Time of manufacture covers 11 years. The one slightly different in the upper frequencies is an older one with a different style mesh over it. The low end variance is noise. You can get that level of difference measuring the same mic twice due to fluctuations in below 100 hz noise.

 

[Salt]

May be I'm completely wrong, but for me this time delay is only a hypothetical fault.
But first: there is more than one software on this planet besides REW, as Arta or Hypex Filter Design, that all would struggle the same problem, not?
Otherwise: is it a real world problem? or only an obstacle for simulating a speaker response (is this the main question)?

For me, as I'm old fashioned, speaker design by simulation has it's place in sub/bass and the enclosure.
Any xover design was and is a dynamic and progressive process of measurement - adjustment - measurement .... in earlier days by switching C's, L's and R's, today by modeling Q's, F's .... with speaker and mic in a fixed position, and after a satisfiying solution then mic moved vertically and horizontically to see if that fits or has to be corrected.
Don't see any problem in time lag here as the whole speaker is measured all the time.

 

[gnarly]

What measurement software do USB mics work with, besides REW?
Do any of them NOT use an acoustic timing reference, like REW's 5kHz up sweep?

 

[Salt]

I think it is not software limited.
I used Arta (sweep and impulse) as well as hypex (sweep) flawlessly.

 

[gnarly]

I think it is not software limited.
I used Arta (sweep and impulse) as well as hypex (sweep) flawlessly.

Cool. But in single channel mode only ?

I'll try ARTA with it, if so.

 

[sam_adams]

A random sample of twenty-five (25) MiniDSP Umik-1 .cal files, 615 points per file:

Cross-Spectrum Labs calibrated Umik-1 .cal files are 1500 points.

A random sample of nine (9) MiniDSP Umik-2 .cal files, 615 points per file:

A random sample of sixteen (16) Dayton EMM-6 .cal files, 256 points per file:

A random sample of twenty (20) Dayton UMM-6 .cal files, 97 points per file:

 

[Blumlein 88]

A random sample of twenty-five (25) MiniDSP Umik-1 .cal files, 615 points per file:
View attachment 360491
Cross-Spectrum Labs calibrated Umik-1 .cal files are 1500 points.

A random sample of nine (9) MiniDSP Umik-2 .cal files, 615 points per file:
View attachment 360492

A random sample of sixteen (16) Dayton EMM-6 .cal files, 256 points per file:
View attachment 360493

A random sample of twenty (20) Dayton UMM-6 .cal files, 97 points per file:
View attachment 360494

Now what you need is the comparison of each mic with its file. One would hope/think the result would group much closer together. A couple of those are pretty out there.

 

[Salt]

Cool. But in single channel mode only ?

I'll try ARTA with it, if so.

Single channel one speaker, what else while constructing?

 

[Salt]

Here my cals, one delivered with Umik (first one), one by vendor (second one):

 

[gnarly]

Single channel one speaker, what else while constructing?

Don't know what you mean by "what else while constructing" ?

Just tried a Umik-1 with ARTA. (I gave up on single channel so long ago, I'm surprised I still had the mic.)
Hey, very nice to see it works like you say! .. with windows WDM driver. Thx.

All that said, screw single channel ....LOL

 

[Salt]

Don't know what you mean by "what else while constructing" ?

Just tried a Umik-1 with ARTA. (I gave up on single channel so long ago, I'm surprised I still had the mic.)
Hey, very nice to see it works like you say! .. with windows WDM driver. Thx.

All that said, screw single channel ....LOL

Under construction means one mic ahead of one speaker.