Simulation of a Mic Capsule

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

dmp

Well-known member
Joined
Oct 28, 2009
Messages
3,829
Location
Madison, WI
Looking for a high quality CAD file for a microphone capsule. Preferably a Neumann and AKG style for comparison.
I work in computational fluid dynamics and am interested in doing a 3D simulation of one.
 
Are you using Comsol Multiphysics?

We use SPICE circuit analogs for simulation. We use a new lossy transmission line method that models diffraction, reflections,
and the like fairly accurately.  It can do responses and even polar patterns.I'm trying to get some papers written about it.

We have CAD drawings of our capsules but they're 2D only.

Les
L M Watts Technology
http://lmwattstechnology.com/
 
leswatts said:
Are you using Comsol Multiphysics?

We use SPICE circuit analogs for simulation. We use a new lossy transmission line method that models diffraction, reflections,
and the like fairly accurately.  It can do responses and even polar patterns.I'm trying to get some papers written about it.

We have CAD drawings of our capsules but they're 2D only.

Les
L M Watts Technology
http://lmwattstechnology.com/
No, I've never used Comsol Multiphysics but it looks like it is an FEA solver. I would like to try a fluid dynamics solver - openFOAM is a open source example. Simplified models should give you good results - I'd just like to try a full 3D detailed analysis for fun.
 
Sounds like a pretty interesting project. I checked out Openfoam.

Comsol has done some MEMs and B&K capsules:
https://www.comsol.com/model/the-br-el-kj-r-4134-condenser-microphone-12375

I'd like to have it, but it's expensive.

With our SPICE models we've extended it to wave effects using lossy transmission lines with a phase velocity=speed of sound.
I mention that in another post here where we model diffraction. One has to be careful though because topology is not preserved.

When I need to know things like the inertance and resistance of a small hole I use Berenek's cookbook formulas, It would be nice to have a fluid dynamics solver.

Here's one for you...a fiber stuffed tube where the fiber moves. It's complicated!

Les
 
If you never find a 3D drawing of a capsule, perhaps you could buy a cheap single-sided capsule and stick it in a 3D scanner. There are a few capsules where one side of the backplate has no diaphragm at all--that would match the side covered by the diaphragm. Using the symmetry, you would be able to complete the 3D drawing without having to take the diaphragm off. This should allow you to do real-world testing to confirm your models.
 
Back
Top