All drivers were EQ'd to be the same - as close as reasonably possible. That said, the frequency response did end up being an audible effect, meaning that small variations in response are audible. The THD was not audible.
Last edited:
Actually I don't know 🙂.
From what I have measured personally, I would highlight Meyer Sound MS-2010. They had distortions even less than 18Sound with beryllium membrane. 🙂.
This is because your setup is wrong or equipment not good enough to see the distortions. You need to measure distortions up to 20k. The distortions start at about 12k following the picture.
It is a pity that the paper does not contain the actual frequency responses of the drivers and the actual THD spectra. It would be interesting to compare the actual difference in the drivers performance. Trust, but verify, as the Russian proverb says.
3rd harmonic of 20khz is 60khz harmonic. Why is it necessary to measure ? 🙄
The actual mic is CEL-192/2F (200V polarized, 3% of THD reaches at 146dB, but I have also RFT mk301, MK202, pair of CEL-186/2R...), preamp is rft-gefell mv201, the amp - MC2 650, analyzer - emu 0404 usb +REW. I have tested the measurement setup in the loopback mode by using a special "dummy mic" that is screwed instead of original capsule (ersatzkapazitat in your native language 🙂). The measurement setup is ok. 🙂
Last edited:
Agreed, and it was discussed. The funder did not want to disclose what the drivers were.
You need to measure up to 40k in REW to see the 2nd harmonic distortion from 10k to 20k. Your mic is not good enough to measure this? please let us see this range. And you should use the RTA to measure distortions which is much more accurate. Furthermore, you need sufficient ppo (48 or even more) between 10k and 20k. Otherwise you measurement hides more that it shows.
Last edited:
For now I can upload the same graph measured for 18sound compression driver, that was measured at the same conditions on the same.
The mic is almost flat up to 20kHz (nonlinearity of freq. Resp. reached up to +1dB relative to mk301). I never measure above 20khz because I don't understand why I need it at all. Actually, I can try to measure up to 40kHz, but first need to find appropriate loudspeaker 🙂. Is there on Diyaudio appropriate topic for acoustic measurements discussion ?
Yeah but why? I guarantee you won't hear practically any amount of 10 kHz H2 (which results in 20 kHz), let alone anything above that.
Looks like a feasible option, mabat.
OS done/gone wrong?
These 2 ways with a OS waveguide (DDS, I believe) and TAD TD-2001 were brought and measured by Joseph Crowe.
Attachments
Last edited:
For now I can upload the same graph measured for 18sound compression driver, that was measured at the same conditions on the same.
The mic is almost flat up to 20kHz (nonlinearity of freq. Resp. reached up to +1dB relative to mk301). I never measure above 20khz because I don't understand why I need it at all. Actually, I can try to measure up to 40kHz, but first need to find appropriate loudspeaker 🙂. Is there on Diyaudio appropriate topic for acoustic measurements discussion ?
NSD 1480 N?
Which horn?
you guessed right. The horn is 18sound 1496c. (MS-2010 was measured with the same horn) 🙂
Yes, effect of audibility of THD was widely discussed, and some conclusions in some papers are not entirely consistent with your findings. E.g. here is
a quote from introduction and conclusion of the paper of dr. A.Voishvillo
My subjective observations are roughly the same as Dr. Voishvillo's remarks, although I cannot fully rely on them since they were not well controlled (I have not performed ABX testing, not equalized linear distortion, etc.). Therefore, I was interested in the details of your experiment.
Last edited:
Don't want to brag, but it wasn't a guess 😉
How do you like the driver(s)?
Last edited:
Actually, I was too impressed with MS-2010, so I don’t remember how good it was. It may seem unexpected, but I was also impressed by Beyma's 755 driver (bearing in mind its price) 🙂.