There has been some discussion in the past on getting B&K or other high quality metal diaphragm mic cartridges to work with non-proprietary audio interfaces. Generally, these systems have odd connectors, require odd power supply voltages. and would require significant DIYing to work with standard USB audio interfaces. While digging around online I discovered the NTI M2010 microphone has a very nice ACO Pacific 7052 metal cartridge, and also has a standard 48V phantom power XLR input. The retail price is $1395, but there happens to be a surplus place in Canada selling a mountain of them for ~$255 ea. on fleabay at current exchange rates.
I called NTI and the rep told me the mic will work with a standard audio interface. He also said they can provide the original factory calibration data by email on request. He said that data should still be valid after many years, assuming the mic hasn't been "knocked around." Alternatively the mic could be calibrated at CSL ($60) or Scantek ($175).
This seems to me like an attractive option for a measurement microphone. Even with precision calibration from Scantek the cost of a used mic in competitive with mics like the Earthworks M23 or iSemcon. Thoughts?
I called NTI and the rep told me the mic will work with a standard audio interface. He also said they can provide the original factory calibration data by email on request. He said that data should still be valid after many years, assuming the mic hasn't been "knocked around." Alternatively the mic could be calibrated at CSL ($60) or Scantek ($175).
This seems to me like an attractive option for a measurement microphone. Even with precision calibration from Scantek the cost of a used mic in competitive with mics like the Earthworks M23 or iSemcon. Thoughts?
@pulexirritans
So did you purchased this mic? Anyone else? How did it turn out?
The advertisement comments about "l show signs of usage, which could include minor scratches, scuffing on housing and minor pitting on the diaphragm"
It's also not clear whether the seller as the ability to clarify is it meets factory spec...
So did you purchased this mic? Anyone else? How did it turn out?
The advertisement comments about "l show signs of usage, which could include minor scratches, scuffing on housing and minor pitting on the diaphragm"
It's also not clear whether the seller as the ability to clarify is it meets factory spec...
@jhenderson01075
I note that you have two samples with the same serial number of 3727- Is this is a typo?
In combination with 1 other user @ ASR, thanks to your data, we now have 6 random samples of the NTI M2010.
They are all within +/- 0.5dB from 20Hz to 2KHz.
Above 2KHz, they have slightly higher deviation.
I've auto-traced and plotted these 6 samples on one graph, and also the mean deviation (red)
My hypothesis is that these tweeters have useful ultrasonic response above 20KHz. This undocumented feature may serve useful for people working / designing with hard dome tweeters:
eg. The same aluminium dome tweeter measured by 3 different microphones: Umik-1 (red), Sonarworks Xref20 (light blue), Earthworks (blue).
All microphones are calibrated by their manufacturers to their specified limits, but only 1 microphone shows the high peaky resonance of this tweeter, which would benefit from a correctly implemented notch filter.
Thanks to other users @Joseph Crowe & @DcibeL we should be able to confirm in the coming weeks whether this NTI M2010 has usable response to 40-50KHz.
I note that you have two samples with the same serial number of 3727- Is this is a typo?
In combination with 1 other user @ ASR, thanks to your data, we now have 6 random samples of the NTI M2010.
They are all within +/- 0.5dB from 20Hz to 2KHz.
Above 2KHz, they have slightly higher deviation.
I've auto-traced and plotted these 6 samples on one graph, and also the mean deviation (red)
My hypothesis is that these tweeters have useful ultrasonic response above 20KHz. This undocumented feature may serve useful for people working / designing with hard dome tweeters:
eg. The same aluminium dome tweeter measured by 3 different microphones: Umik-1 (red), Sonarworks Xref20 (light blue), Earthworks (blue).
All microphones are calibrated by their manufacturers to their specified limits, but only 1 microphone shows the high peaky resonance of this tweeter, which would benefit from a correctly implemented notch filter.
Thanks to other users @Joseph Crowe & @DcibeL we should be able to confirm in the coming weeks whether this NTI M2010 has usable response to 40-50KHz.
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@DcibeL and @Joseph Crowe both agreed to do some testing, however before I could have it sent to them, I received some correspondence from Noland Lewis from ACO Pacific, who are the North American representatives for ACO Co Ltd, Japan. He was very informative about their products, including a recommendation based on my needs.
Anyway, in passing we discussed the 7052E capsule as used in their 7052PH. He confirmed that it is flat to 25 KHz, and “rolls off over 12 dB above 30 kHz or so...”
So despite the website looking like it could do with a C21 update, they are alive and well. In fact I recently saw a Full page advertisement in the most recent Voice Coil magazine.
The NTI M2010 preamp is a little noisier, but certainly a sufficient mic if you’re going to build a robotic measurement device. The 7052PH is ~US$900 new, which for an American Made phantom powered preamp with a metal 1/2” free field capsule, is certainly competitive with a new NTI mic, or even the Earthworks M30, with the mylar diaphragms.
Anyway, in passing we discussed the 7052E capsule as used in their 7052PH. He confirmed that it is flat to 25 KHz, and “rolls off over 12 dB above 30 kHz or so...”
So despite the website looking like it could do with a C21 update, they are alive and well. In fact I recently saw a Full page advertisement in the most recent Voice Coil magazine.
The NTI M2010 preamp is a little noisier, but certainly a sufficient mic if you’re going to build a robotic measurement device. The 7052PH is ~US$900 new, which for an American Made phantom powered preamp with a metal 1/2” free field capsule, is certainly competitive with a new NTI mic, or even the Earthworks M30, with the mylar diaphragms.
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