panasonic wm6a omni -> cardioid?

Hi all!

I've been using these capsules for some time, and really like them, particularly the linkwitz mod. They have an omni pickup pattern, but I would really love to have one in a cardioid response. Is it possible to perforate the back somehow, or possibly mount it on a large sphere (1foot diameter casts about a 1kHz shadow?)

Any thoughts?

I'm pretty sure all that will happen when you poke holes in the back of one of those capsule is you'll lose your low frequency response.

And I have no clue how (or if it's even possible) to turn those into cardioids. I'm sorry I'm not more help.

JC

Put two back to back, just like we do with LD condensers.

[quote author="zebra50"]Put two back to back, just like we do with LD condensers.[/quote]

No, that doesn't work! And the problem with poking a hole is the tuning of the diaphragm I think? But there are (several) other ways to use omni capsules for a more directional pattern. Won't be a cardioid however, different principles of operation.

Start with mounting them flush on a flat surface (a hole in a board). That's already a big change. Then there's the PZM concept. Next you've got the sphere idea (and other shapes). A parabolic mike works with omni capsules. Finally I can think of using a larger number of these spread out.

Experiment and enjoy!

Martin

[quote author="zebra50"]Put two back to back, just like we do with LD condensers.[/quote]

Sorry - I misread the first post and thought you wanted to make an omni from a cardioid, not vice versa. My bad.

:thumb:

Psonic used to make similar capsules in cardioid and close-talk versions.

I think Psonic has dropped the line but a chinese company has the same model numbers.

The cardioids are broad and most have droopy bass. This is the natural consequence of getting tricky for two dollars.

There were one or two which were wide-band enough for music. It takes a bit of hunting to find the right models; sorry, I do not have my notes any more.

Small omni on large sphere is not a broadband cardioid but does give a very useful directivity. Large flat baffle gives broad directivity. A 2-way or 3-way corner "sees" less of the world but when large enough to corner bass is impractical.

[quote author="PRR"]Psonic used to make similar capsules in cardioid and close-talk versions.

I think Psonic has dropped the line but a chinese company has the same model numbers. [/quote]

Yes, Pansonic-like capsules are manufactored in Taiwan/China.

http://www.chiaping.com.tw/showproducts1.php (you need to buy them in 10000ths...)

Here is another source:
http://www.jlielectronics.com/transsound/electrets/ts-60a.htm


Roger

Think I've hear a few of these "clones". All had one thing in common, sounded terrible. Don't know exactly why though.

But then again, there's a bunch of mikes out there that sound like crap...

Martin