Parts for a low noise wideband MEMS studio microphone

I recently posted a model for some parts for use with a MEMs microphone chip (Knowles SPH1878LR5H-C) to make a measurement quality microphone that has extremely even response over a very wide frequency range and with omnidirectional pickup up to beyond the audio frequency range (https://www.printables.com/model/1271594-parts-for-a-mems-based-precision-measurement-micro).  That microphone is nearly ideal for frequency response measurements of loudspeakers or for research. However, its internal noise level is too high for use as a studio recording microphone.  That is due to the noise characteristic of the MEMs chip which has a very small diaphragm.

So this model is for a way to mount and combine 7 of the MEMs chips together to improve the noise level.  Noise is reduced by 8.5dB (down to about 18.5dBA), making it usable for high performance recording in all but very quiet rooms.  Maximum signal handling (134dBSPL) is high and unchanged.  On-axis frequency response is within 3dB from 9Hz to 80kHz.

The omnidirectional behavior, though, isn't as good as for the mic with the single chip because of the larger area occupied by multiple MEMs devices, but audible band response is still flat within 3dB even to 60degrees off axis.

This is accomplished by having the chips mounted as if on a surface of a ½" (12mm) half-sphere.  The finished microphone mount attaches to a ½" diameter stainless steel tube.

As with the previous microphone design, the holder has to be printed on a resin type printer for the needed precision at small size.  As I don't really think anyone else is likely to try the make any of these (wiring up the 7 chips isn't easy), I'm not listing build instructions nor the details for the low-noise preamp need to equalize the array and interface it to XLR microphone inputs.   The circuit is similar to the one for the previous MEMs mic, and mounts externally about a meter away from the main mic stand in a similar (printed) box.  
But –  if by chance you should need ultra-high quality microphones for precision recording and want to try building a set of these, contact me and I can get the information together!

I don't have a way to measure noise levels this low, too much environmental noise where I am.  Probably there is a way to embed one of these mics in a large box of sand to measure, but that's a lot of work so I'll trust that the calculated/simulated noise levels for these is correct.

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I've also attached stl files for fixtures to use when gluing and wiring the MEMs chip to the holder.  

And also a file for a larger MEMs array using 13 chips (I never finished that one, after finding how difficult would be to wire 13 chips using 39 fine gauge wires!).