Four KM-84 Clones - Blind Test

[joulupukki]

Interesting. So with C2 at 2.2/3.9pF the high pass frequency shifts even higher? …and the mic would have an even higher sensitivity in the high end?

Ignore that question. I loaded those same .mdat files in REW and now understand what you mean. I should put in a pad capacitor in C2 in the MP mic and see what ends up happening in real life recordings. Ah, except I don’t wanna touch those tiny screws in that mic body again. I need to find some replacements. When I first started with those mics I wasn’t delicate enough and I ended up nearly ruining the slot on the screw head. :-|

 

[joulupukki]

I don't know if anyone else will find this interesting, but since I can't currently record all 6 microphones at the same time (because I need to get some better XLR connectors), I decided to see how pink noise is recorded by each of them. In the following image, what you'll see is that the KM84+ is used as the "base" EQ. I used FabFilter's Pro-Q3 to do an EQ match with the KM84+ recording pink noise.

If you see the yellow line going UP past zero, that means that in order to sound like the KM84+, the mic EQ has to be raised at that point. Lower than 0 means the EQ at the given frequency has to be lowered.

Something else interesting (confirming what I'm hearing) is that I swapped the MP SDC-84 capsule for a 3U Audio Capsule and did a recording with the MP SDC-84 of pink noise. See the big drop at the high end frequencies on the stock MP SDC-84 capsule?

With the KM84++ I'm seeing that the low end needs to be raised to match the KM84+. Also, like I can hear in the recordings, 5-15kHz has to be raised in order to match the KM84+ ... confirming why I'm not hearing as much definition out of the KM84++ as the KM84+.

This also includes the stock Takstar CM-60 and CM-63 and it's interesting to see that they both have a mid scoop compared with the KM84+. The CM-63 has a lot more high end above 8kHz compared with the KM84+. When I was comparing the CM-60 earlier this year against my Graeme Woller KM84 build, the CM-60 sounded really close except it had significantly more low end.

 

[jp8]

Interesting. So with C2 at 2.2/3.9pF the high pass frequency shifts even higher? …and the mic would have an even higher sensitivity in the high end?

No, maybe my description wasn't clear, but it's actually the other way around. The green line shows low-end roll-off with C2 = 0 pF and roll-off point moves to the left to a lower frequency.

Gain (or sensitivity) increases when C2 decreases and is limited by the open-loop gain of the JFET.

Jan