Class 1 only concerns frequency linearity pre-calibration for a microphone. You can have a nice stable class 1 mic from an electret mic like the M23:
https://audioxpress.com/article/fresh-from-the-bench-earthworks-m23r-measurement-microphone
Well there can be differences in purity vs other processes and of course differences in crystal structure (with different types of heat processing and post-processing like annealing); also the exact alloy might be different, notably however - typically the substrate is still part of the result for something like a mic. diaphragm and it might not be sputtered on both sides.
note: sputtered = vapor deposition.
The Dayton Audio EMM-6 and Behringer ECM8000 are the cheapest alternatives out there, and may be the exact same microphone. The Behringer doesn't come with a calibration file but unfortunately the Dayton's are notorious for having bad calibration files. So yes, if you want to stick with the inexpensive ones then a Cross Spectrum Calibrated one would be my recommendation. BUT...Cross Spectrum hasn't updated their page since April 2022 when they posted that some EMM-6's would be in stock soon.
These DO work fine for crossover work, at least with a good calibration file - or without one if you trust your ears that much. But they are NOT the "best" available out there. You probably don't NEED it, but the Earthworks M23 and M23R are much better and much more expensive.
The Panasonic WM-61A capsule was the benchmark for excellent cheap microphones.
To find a hoard of NOS has been, for the last decade, like the quest for Eldorado, almost mythic.
At that price you shouldn't even hesitate.
Best wishes
David
Edited
A quick check of the site showed: out of stock/not available.
Like I said, mythic.
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Yes the one for Sound Level Meters, for whatever reason Mic manufacturers use it in their specifications.
This isn't true, but with the standard being expensive and not open it is hard to know exactly what is the difference. All I can find is that it must meet the frequency response and be stable within certain heat, and humidity ranges. That seems to be the kicker and why only very few of the cheaper microphones claim to be Class 1 rated overall.
E.g isemCon's data sheet states "Its class 1 frequency response (NOTE: NOT A CLASS 1 MICROPHONE)*"
The Class 1 frequency response covers quite a lot of mics so it may not be particularly useful in selecting a home measuring mic anyway.
Another thread on a similar topic
https://www.audiosciencereview.com/...crophone-1-2-1-4-vs-class-2-calibrated.23362/
The best XLR measurement mic that's available out there, for speaker measurement probably the Microtech Gefell MV225 plus MK202 capsule. More than $3K in NZ. I expect.
Did you mean "What's the forum consensus on a cheap XLR measurement mic..."?
Best wishes
David
I think the designation: “class 1” is only intended for SPL-meters. IEC6172. A Measurement Microphone wouldn’t qualify as “class 1” because it’s not an SPL-meter. Perhaps then a “class 1” mic meets more of the parameters for a class 1 SPL-meter than just the linearity?
IEC61094-4 (which I think lasted less than a year before being removed) concerned Measurement Microphones and did have many parameters but I believe not designated as “class 1 or 2”.
-anyway, it’s really just “academic”. I’m sure the M215 will be far more stable than any electret mic’s - including the Earthworks mic’s.
IEC61094-4 (which I think lasted less than a year before being removed) concerned Measurement Microphones and did have many parameters but I believe not designated as “class 1 or 2”.
-anyway, it’s really just “academic”. I’m sure the M215 will be far more stable than any electret mic’s - including the Earthworks mic’s.
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Those haven't been available for a while (or their website is broken). Try to check out and you'll get a "no longer available" message.
FWIW, I like the iSemcon mics. I had a matched pair of Earthworks M30 and sold them after discovering iSemcon. One thing I don't like about Earthworks is their factory cal is on axis only. They do have a generic calibration for grazing incidence but at that price I want the real thing. (Grazing is used for measuring in room at a listening position, as opposed to direct field.)
I'd be curious to see if anyone's gotten a third party cal of the Neumann MA-1 microphone, the one Neumann started selling for room correction for their (elite-grade) studio monitors. Those don't have axial calibration, only grazing.
B&K have been established as the the safe "best" option for sound and vibration hardware since the 60s. They don't compete aggressively on price but providing a full solution for professionals working in the field. A measurement microphone is effectively useless without a valid calibration because they are not linear with frequency. Accredited calibration services (more expensive reliable ones) are required for measurements to be accepted by significant numbers of bodies and institutions like courts. Calibration is also required to have been performed recently with annually being fairly common though the period varies depending on who the measurements are for.
Professional hardware is usually too expensive for a DIY hobbyist to consider but knowing what it is and how it is used is likely to be useful. B&K for example have a very good and extensive online library explaining what is involved in taking valid measurements.
Yes, those who can think of EMM-6 and ECM8000 could always go for capsules .... AOM-5024 is available these days ...
I have 3 measurement mics
1) MiniDSP UMIK-1: bought 4 years ago
2) Dayton EMM-6: bought 2 years ago
3) Sonarworks SoundID reference mic: bought less than a year ago
Here is a comparison between the EMM-6 & UMIK-1 mics measuring a driver (with mics & driver kept at almost the exact same location and height)
Red trace is that of the dayton emm-6 and green trace is that of the minidsp umik-1
Here is a comparison between the Sound ID & UMIK-1 mics measuring a driver (with mics & driver kept at almost the exact same location and height)
This time, the red trace is that of the minidsp umik-1 and green trace is that of the Sound ID
(Unlike the legend in the above pic, driver was measured from 1m away and not measured nearfield)
To my ears, the sound calibrated with the soundID reference sounds the most balanced among the 3 mics.
Only God knows which one of them is the most accurate (although I like to believe it is the Sonarworks SoundID reference).
I have no way to verify the accuracy of these mics at the moment, well, at least until my ISEMCON EMX-7150 reaches me in a couple of weeks (with the hope that at least that one is the most accurate)
1) MiniDSP UMIK-1: bought 4 years ago
2) Dayton EMM-6: bought 2 years ago
3) Sonarworks SoundID reference mic: bought less than a year ago
Here is a comparison between the EMM-6 & UMIK-1 mics measuring a driver (with mics & driver kept at almost the exact same location and height)
Red trace is that of the dayton emm-6 and green trace is that of the minidsp umik-1
Here is a comparison between the Sound ID & UMIK-1 mics measuring a driver (with mics & driver kept at almost the exact same location and height)
This time, the red trace is that of the minidsp umik-1 and green trace is that of the Sound ID
(Unlike the legend in the above pic, driver was measured from 1m away and not measured nearfield)
To my ears, the sound calibrated with the soundID reference sounds the most balanced among the 3 mics.
Only God knows which one of them is the most accurate (although I like to believe it is the Sonarworks SoundID reference).
I have no way to verify the accuracy of these mics at the moment, well, at least until my ISEMCON EMX-7150 reaches me in a couple of weeks (with the hope that at least that one is the most accurate)
I ordered one along with its calibration file and the PCB. I haven't received it yet.
I already use a WM61A capsule with a generic cal file and the old Eric Wallin designed preamp (the cal file obviously not exactly ideal) so thought I'd jump in and grab them while available.
Silicon Chip used circuitry to correct some of the response anomalies for each batch of capsules, and a unique cal file to fine tune it, with a view to making the mic somewhat usable without the calibration file.
Have you ever checked the allowed tolerances for a Class 1 microphone?
It's fine for general acoustics, but for loudspeaker design, no thanks.
What the IEC-61672-1 standard does, like any other standard, is to ensure a default platform or reference.
In this case, to make sure that acoustic engineering companies all test and measure according the same reference.
Since there are many legal implications involved, like environmental and safety laws, this is basically mandatory.
Totally not interesting for loudspeaker design.
It's mostly just paperwork you pay for and like I said, even the tolerances themselves are meh.
To lazy to dig up the official documents I have stored somewhere, but this graph will give you the basic idea;
What I'd really love to have, even over and above the best mic on the planet, is one of the machines that calibration files are made with, like this guy....
https://www.modalshop.com/docs/them...tion-datasheet-ds-0007.pdf?sfvrsn=362d2242_12
I'm totally dreaming of course...no idea what such type kit costs....
I'm another happy camper, with the iSemcon EMX-7150. No clue how totally accurate it is, but i did get to measure it against a pair of M30's at a measurement workshop, and all three mics looked nice and close.
I use the iSemcon as a calibration device for a handful of the very low cost ECM8000s, by building a txt file to get the each of the Behringers to match it.
(Because I have an outdoor vertical mast that holds 5 mics...and don't want the expense of 5 EMX-7150, or the sometimes potential weather exposure before I can strike the rig).
Here's a trace of the EMX-7150's measurement of a speaker, and 5 ECM8000s with txt file calibration made for each of to match the EMX.
Seems to work well I think.
I offer this as an idea for those needing a XLR mic, moving on/up from a Umik.
IF you have confidence in your Umik, get whatever XLR, and match the Umik.
Save some $$.
https://www.modalshop.com/docs/them...tion-datasheet-ds-0007.pdf?sfvrsn=362d2242_12
I'm totally dreaming of course...no idea what such type kit costs....
I'm another happy camper, with the iSemcon EMX-7150. No clue how totally accurate it is, but i did get to measure it against a pair of M30's at a measurement workshop, and all three mics looked nice and close.
I use the iSemcon as a calibration device for a handful of the very low cost ECM8000s, by building a txt file to get the each of the Behringers to match it.
(Because I have an outdoor vertical mast that holds 5 mics...and don't want the expense of 5 EMX-7150, or the sometimes potential weather exposure before I can strike the rig).
Here's a trace of the EMX-7150's measurement of a speaker, and 5 ECM8000s with txt file calibration made for each of to match the EMX.
Seems to work well I think.
I offer this as an idea for those needing a XLR mic, moving on/up from a Umik.
IF you have confidence in your Umik, get whatever XLR, and match the Umik.
Save some $$.
Good to see discussion on the topic. I searched and couldn't find anything recent. There are more options out there than I thought. Might be interesting for future reference to list all options and price points.
Also the mic doesn't have to "be in NZ" as its not hard to ship a mic around the world. So for the purposes of this discussion we can probably not factor in shipping costs, unless one were looking at entry level mics where shipping is almost the cost of the mic.
I guess to sum it up - I'm looking for the next "level up" from what I have here.
What I mean is during the crossover design that the highest treble measured means the final speaker design needs less treble boost, if that makes sense. The one that measures the most treble output, needs less to correct to "theoretical flat" response. I think we're on the same page.
A good idea, reference the "bad" mics to a known good, assume this was done by making own calibration file with an "A minus B" scenario? I've never tried this. Be interested to hear more.
Thanks Charlie - kind of answer I was looking for - I will check earthworks and also @fluid 's mention MicW M215 / EMX-7150
Hah - yeah nah I didn't mean cheap, but I did hope to level up from what I have, I'm willing to spend more for something decent. $3k is probably past the point of diminishing returns for mics, as far as DIY speaker design goes, you recon?
Yeah, last time I tried they were having freight issues and said they couldn't get anything out to me. That was a while ago, so not sure what's happening over there now. It's an ancient website design and doesn't look regularly updated.
More good info - thanks. Yes, I'm not sure I need to delve into "professional" market mics yet.
Also the mic doesn't have to "be in NZ" as its not hard to ship a mic around the world. So for the purposes of this discussion we can probably not factor in shipping costs, unless one were looking at entry level mics where shipping is almost the cost of the mic.
I guess to sum it up - I'm looking for the next "level up" from what I have here.
What I mean is during the crossover design that the highest treble measured means the final speaker design needs less treble boost, if that makes sense. The one that measures the most treble output, needs less to correct to "theoretical flat" response. I think we're on the same page.
A good idea, reference the "bad" mics to a known good, assume this was done by making own calibration file with an "A minus B" scenario? I've never tried this. Be interested to hear more.
Thanks Charlie - kind of answer I was looking for - I will check earthworks and also @fluid 's mention MicW M215 / EMX-7150
Hah - yeah nah I didn't mean cheap, but I did hope to level up from what I have, I'm willing to spend more for something decent. $3k is probably past the point of diminishing returns for mics, as far as DIY speaker design goes, you recon?
Yeah, last time I tried they were having freight issues and said they couldn't get anything out to me. That was a while ago, so not sure what's happening over there now. It's an ancient website design and doesn't look regularly updated.
More good info - thanks. Yes, I'm not sure I need to delve into "professional" market mics yet.
I have 3 measurement mics
1) MiniDSP UMIK-1: bought 4 years ago
2) Dayton EMM-6: bought 2 years ago
3) Sonarworks SoundID reference mic: bought less than a year ago
Here is a comparison between the EMM-6 & UMIK-1 mics measuring a driver (with mics & driver kept at almost the exact same location and height)
Red trace is that of the dayton emm-6 and green trace is that of the minidsp umik-1
Here is a comparison between the Sound ID & UMIK-1 mics measuring a driver (with mics & driver kept at almost the exact same location and height)
This time, the red trace is that of the minidsp umik-1 and green trace is that of the Sound ID
(Unlike the legend in the above pic, driver was measured from 1m away and not measured nearfield)
To my ears, the sound calibrated with the soundID reference sounds the most balanced among the 3 mics.
Only God knows which one of them is the most accurate (although I like to believe it is the Sonarworks SoundID reference).
I have no way to verify the accuracy of these mics at the moment, well, at least until my ISEMCON EMX-7150 reaches me in a couple of weeks (with the hope that at least that one is the most accurate)
I have similar measurements except I think my order may be the other way around. Will have to dig them back up and check. Thats crazy though, a 6-7db difference at 10kHz between the emm6 and the sound ID. Thats crazy audible (if one is used to design a speaker vs the other). And 3db around 5khz, that can fatigue you.
Yes and in terms of frequency response alone it means nothing. The image you posted was in the link I posted above. The point was that there are some other factors that detemine the Classes such as stability with heat and humidity. Where I live this could be an important factor.