M7 DIY Reskin

Hi guys.
I bought cheap this demolished capsule from Cathedral Pipes  in hope that i can do something to it, and experiment a bit (it ended up in water). Membrane got stuck on both sides and i tried several things but it just wouldn't separate from the backplate on both sides. I even tried to blow some air through tiny vent hole on the side. Didn't work.

So i just thought, what to hell, i'll just take one membrane off, and blow carefully from the back side. And that is exactly what i did. I actually gave this capsule CPR

It worked, it separated beautifully. I just had to reskin the other side. So i thought, should i go vintage or modern?  Oh well, vintage for sure, so i went to my kitchen, took some PVC plastic food wrap from my wife. It's about 10 μm thick so it should work xD

I stretched the foil over a coffee cup, applied some Loctite glue that works well with PVC on the edge of the capsule, and just stuck the cup with the wrap over the capsule and put a book on top of it. I didn't stretch too much, as i know m7 has lower resonance, but how much? I have no idea.

Several hours later, i put it in mu modded Behringer B2 body, and god damn thing sings like a charm. And the polar pattern is right, and beats my favorite diy u47 fet  with Dave Pearlman capsule. Pearlman capsule sounds like a can compared to it.

I am sorry i didn't take all the pictures during the ''procedure'', but i didn't expect it would work at all. Here are some, and i promise some audio samples as well.

And please don't try this at home!

Initial state of the capsule:

Front side after ''CPR''

''Reskinned'' side. Tricky to take proper pic because of reflections, but it's perfectly flat.

And my hi tech jig.

You're a hero! 

Where there's a will, there's a way ;D Ooooor something-something...

Or, in the words of YouTube's AvE - "It's already f**ked, what're ya gonna do? F**k it more?" In translation, "nothing to lose", basically

Something like that. As long as no one follows my instructions everyone is safe
I am a bit worried that Thiersch might read this and steal my patents xD

https://www.youtube.com/watch?v=6zXDo4dL7SU ;D

Same distance, position etc. short loop through my monitors.
Pearlman and M7 are in the same body, i just swap heads with different capsules (Another great feature on Behringer B2)

M7:
https://app.box.com/s/v7fu7rfds077kns4tnh6g60qd0cbrr6m

Pearlman k47:
https://app.box.com/s/6emo13qdwpuvs170i61k2miinuhge47i

Shure KSM44 (kind of reference mic)
https://app.box.com/s/z88mplf0s4c4yutz4u162k29dk7ffq9p

Wow, that is a night and day difference. Your M7 sounds really good compared to the pearlman!
Hmm, I have an original K87 with a hole in the membrane... Maybe I should try that too
No, I'll follow your disclaimer But serious, great job!

Great work! That's the diy spirit!!!!!!

Hello
Do I miss something?
I don't get how it work without membrane metallization  ??
Best
Zam

It's an M7 Cardiod only then  ;D

I'm impressed, congrats for your courage and ability.

I'm pretty sure that in the last 3 years you even went deeper and are able to do a lot of different work in capsules

chefducuisine said:

It's an M7 Cardiod only then ;D

Click to expand...

Why you should never use multi pattern mics

Yup, my first skinning attempt ever. I've learned quite a bit in the meanwhile, that capsule was standing strong for several years, performing well and is still in my main M7-u47 mic.

In 2021 i re-skined it again with different material and metal so i get to switch sides for different voicings. Now it's multi pattern and dual mode cardioid. So to say purposefully mismatched sides.

kingkorg said:

Yup, my first skinning attempt ever. I've learned quite a bit in the meanwhile, that capsule was standing strong for several years, performing well and is still in my main M7-u47 mic.

In 2021 i re-skined it again with different material and metal so i get to switch sides for different voicings. Now it's multi pattern and dual mode cardioid. So to say purposefully mismatched sides.

Click to expand...

Very interesting. Congratulations for your work.
Can someone share where to find in Europe suppliers for material suitable to be used as a diaphragm? I have a couple of broken inexpensive large diaphragm capsules to make tests.
I read about possibility to make a sort of "sputtering" with spray metalized paint but if someone has other advices are greatly appreciated.

Very cool thread. Nice work on salvaging that capsule. I have an expensive M7 that I was trying to find someone to reskin, but the prices have made it cheaper to just buy a new one. Maybe some experiments are in order. Getting the mylar that is already sputtered would be kind of important for me. I'm not sure I'm aware of anyone selling it though.