Stretching a metal coated diaphragm with no clamps or bolts.

Hey all!

I'm interested in building a small microphone's capsule. Sounds out of the ordinary, right? ;D

Well, there are a lot of information available on-line, but there is something I couldn't find:
I'm interested in building a small capsule, were the diaphragm is stretched with no holding clamps, no bolts on the frame, and no central terminal wire.

To hold the diaphragm in place, I thought about electricity conductive Epxoy, since there has to be an electrical connection between the membrane and the housing.

Please refer to the picture to illustrate the type of capsule I'm interested in.

Does anyone have experience with it?
Can anyone refer me  to  information on how to do it?

Many thanks

Welcome! 

Have you seen this thread?
https://groupdiy.com/index.php?topic=21005.0

or said:

Does anyone have experience with it?
Can anyone refer me  to  information on how to do it?

Many thanks

Click to expand...

The attached picture shows the simple and effective answer to your question ,  used by a quite well known german mic company.  No conductive glue necessary if you want to connect the diaphragm to ground (housing).

Note the Alu-sputtered diaphragm. Perfectly fine unless you expose the mic to nasty conditions.

Even simpler solution for you:  just use the diaphragm of the ripped capsule in your picture.

Thank you for your reply Micaddict and MS Viena.

I have read some articles in the attached thread, and now I know I'm looking for an edge-terminated capsule. Thank you for that!
But I didn't find any articles referring to mounting the diaphragm without the clamping ring and bolts.

As for the answer from MS Viena, I want to build my own capsule so I cannot use the capsule in the picture.
Also, I didn't quite understand how the diaphragm is connected from your picture. Can you please elaborate on that?

Thanks for the help!

On the picture you can see that the metalized film (diaphragm) isn´t trimmed flush with the ring that holds it. Some excess material is left outside the ring. This inevitably will make electrical contact with the microphone´s metal housing.
To accomplish that in your DIY-project you need to have a pretty precise fit of the capsule inside it´s housing.

Making capsules isn´t a sunday afternoon project. Be prepared to invest lots of time (and money) to get decent results.

Thanks for the reply and concern  ;D
although, time and money is not an issue for the near future...

I liked your method to maintain an electrical connection with the housing, but on the acoustic level, it can cause problems. the execs foil can vibrate and make a humming sound when vibrating towards the housing.
besides, I think I can do better than that, don't you think?  8)

The main question was, and still is: Does anyone has a reference on how to mount the stretched diaphragm on the diaphragm ring, without clamping and bolts, and still maintain an electrical connection between the metal side of the membrane to the metal ring that holds it in place.

Do you think they apply heat and pressure when they build those kinds of capsules?

or said:

the execs foil can vibrate and make a humming sound when vibrating towards the housing.

Click to expand...

Theoretically. If done right this method works fine.

or said:

Do you think they apply heat and pressure when they build those kinds of capsules?

Click to expand...

Techniques like these are usually proprietary to the manufacturers, so probably there are no tutorials about this anywhere.
However, heat and pressure is a very good starting point for your R&D work.

Thank you for your reply.
I will keep this post still here if anyone has some insights on this.

Super cool you're interested in this!

You might contact member Poctop here, who has done exactly what you are trying to do, from scratch. I'm sure he can give you some valuable insights and ideas.

Actually another member, tskguy, has also done this too, so you might hit him up for ideas as well. These are both super nice guys and I'm sure would be happy to share at least some of their ideas with you.

Welcome to GDIY!

Mike

I can give you some insight,,,, Hit me up with  a PM.