dragonfly capsule design

[Gus]

from another thread

http://www.violetusa.com/Default.aspx?tabid=260

I counted 26 holes in one and 22 holes in the other?

JZ is this capsule kind of like the tlm103 and cardiod only 797 with the plastic backplates and brass front plates(kind of like a 67/87 front plate) designs? or is it resonater based?

I am not saying the same but the same basic idea. Good capsules are all about the little things.

The drilling is interesting, making me think there is a clear PET skin over that side because of the larger size volume drilling with a smaller thur drill. The holes being on the outer part of the plate has me thinking.

The capsule pictures got my attention and I am wondering if others here are thinking about the design

 

[Emperor-TK]

Bad netiquete aside, JZ keeps making a lot of good points when it comes to the question of "who is the real Blue". Those capsules are remarkably different. I'd be pissed if I bought a new Dragonfly and didn't get a mic that was actually a Dragonfly.

JZ, you have some stong evidence that supports your claims, you need to drop the shill tactics. :?

-Chris

 

[Guest]

I have been thinking about this a little... Gus I think you are correct about the PET on the side shown in the pics... you can see what looks like PET on the left side of the JZ capsule near the screws. I'd like to see the front...

 

[Tim Campbell]

Sorry for piping in here as I'm not JZ. After looking at these pictures I'd say there is no rear PET film on these capsules. It isn't necessary as long as the rest of the capsule doesn't require extra dampning from a closed air space. I've made quite a few different designs lately this way that sound good. All Schoeps capsules (except omni) and all small membrane capsules (except omni) are made this way.

These pictures are decieving in that the capsules appear to be different sizes but aren't. The difference in the amount of holes and the fact that the capsule to the left's holes are slightly closer to the center of the mic would contribute most to the difference in the sound of these capsules but even this difference could be overcome with the right adjustment of other critical dimensions.

 

[Gus]

Tim

What I don't understand is the larger drill size used with the small hole at the bottom. Could this be to allow a thicker plate with low air resistance because of the larger cylinders (air volume) behind the small holes?

If it was a thin plate it might resonate?

 

[dale116dot7]

One thing I can think of as well, drilling a long, slender hole is very difficult (lots of broken bits and other troubles if the depth is greater than 3 times the diameter of the bit). The added space would seem to me to prevent this. In addition to what was previously mentioned - this might be an extra bonus to consider.

I have not looked carefully at this capsule - what does the rest of the capsule look like?

 

[Tim Campbell]

Dale and Gus,
You may be right about the reason for making the back holes this way. The critical points about the holes are the actual opening size (the dimension of the small hole) and the distance sound has to travel to reach the back of the membrane.

 

[alk509]

[quote author="Gus"]What I don't understand is the larger drill size used with the small hole at the bottom.[/quote]

As you guys were talking about this, I just knew I'd seen this somewhere else... MY OWN SITE!

I don't know if it's relevant or not, but the Chinese capsule I dissected does the same thing: big holes in the front with small through holes. Check it: http://home.comcast.net/~alkoury/34mm.html

Peace,
Al.

 

[Gus]

Al

Neumann type backplates are made like that. The bigger holes are for air volume between the skin and back without making the distance to great between the skin and backplate. The thur holes are for the time delay network, velocity part of the design.

The DF has this on the backplate without any inclosed air volume so with the DF it must be for a different reason.