New CK12 capsule measurements

[Kwinn]

It doesn't really matter. They got some things right, some things wrong. I had given them a price that they could hire me to teach them this. They told me they don't pay anyone real money for their work .

Any burn marks I am sure are because they do not know processes required for these materials. They are reading this so I won't contribute more in public but please PM me.

We are simply doing their R&D work.
You can see from the dates they joined they have been members for a long time but only first posted now.

To be fair, AKG did the important R&D work.
I guess, reverse engineering their design, missing or altering a few things could be called R&D, as well... ;-)

 

[Tim Campbell]

To be fair, AKG did the important R&D work.
I guess, reverse engineering their design, missing or altering a few things could be called R&D, as well... ;-)

Actually Wente did all the important work. AKG copied him . I have said in many posts over many years that my work was based on AKG's. They helped me and gave me their blessing but did not do 1 minute of all the emperical work for me (which is what we are discussing now) which is required to make a capsule that performs correctly and consistently.
Measuring parts tells you almost nothing about a capsule as we can see here.

 

[Kwinn]

Actually Wente did all the important work. AKG copied him . I have said in many posts over many years that my work was based on AKG's. They helped me and gave me their blessing but did not do 1 minute of all the imperical work for me (which is what we are discussing now) which is required to make a capsule that performs correctly and consistently.

Semantics. Of course, AKG did not invent the condenser caspule, but took it to sonic perfection with their patented design. Before that, it required many years of technological/industrial advancements and empirical groundwork from companies like Neumann. I think it's safe to say that AKG did not simply copy the man.

EDIT: Of course, Neumann also came up with their own interpretations of sonic perfection.

 

[soliloqueen]

It's hard to get everything right when launching a product. Didn't you have problems with shorting backplates and wrinkling membranes lately?

Yep! And it's not because launching a product is hard, both the issues with this CK12 and the issues with my K87 happened because of the "accelerated product development" approach I'm criticizing here. It's not a reasonable way to develop a product and adopting that approach created all sorts of issues for me that I'm still solving. That's exactly how I know!

 

[Kwinn]

Sorry for being off-topic. I just wanted to give a different perspective on a few things.

 

[soliloqueen]

Sorry for being off-topic. I just wanted to give a different perspective on a few things.

No worries! My experience personally was a good lesson in "knowledgeably specify every aspect of your design"

 

[Icantthinkofaname]

About what I expected too, though I was looking forward to a cheap CK12. Looks like I'll be waiting for 3U's version and possibly using a TLII capsule if I can get one.

 

[OPR]

Hello! The wait is over.

Before i continue, please refrain from non related, political issues, personal attacks which led this thread to be locked.

The two capsules from Alex, @RuudNL provided contact to, have arrived. I tested just one of them, i dont expect the other one to be any different.

I have no horse in this game, but i have hoped we get cheaper, and easily obtainable CK12 for our DIY projects.

This thing has nothing to do with real CK12. Not @Tim Campbell 's, not anyone else's, and most certainly not Akg's.

Yes there are many faces of CK12, and it can be tuned in so many ways, but this is not one of them. I believe the issue is, Alex's company doesn't have the blueprints on how to tune the capsule, or even measure it.

180° is way off, never seen anything like it, not cardioid for sure. 0° shows typical response of badly tuned CK12 of any type, even recent plastic ones. Bump in low mids, sharp HF peak is a no-no! Some Akg c3000 had response like this.

If this thing can even be properly tuned remains to be seen. Stock it is unusable.
About 105pF diaphragm to backplate, 52pF between backplate halves.

I tag @alloitsjosh as he asked about the measurements.

Thanks for posting this!
Looking at the frequency measurements and electrical parameters a it's a obviously a mile off in many ways.
I won't describe the why as I don't want help with their R&D. but I'll suffice to say that you don't need the blueprints or access to AKG to reverse the ck12, although it would make the process much more expedient and and infinitely easier.... You do however need an extreme level of attention to detail and persistence to crack the many layers Ck12 code. I can see why AKG gave up on it as it's not built for mass production, but rather sonic perfection.

 

[kingkorg]

The diaphragm is 4 microns thick. Here's the image of one of the backplates facing the diaphragm. Unfortunately diaphragm is not glued so i couldn't tell how it was tensioned, but if i go by measurements too high. After the re-skinn at right tension FR started looking much better.

 

[Icantthinkofaname]

Thanks for posting this!
Looking at the frequency measurements and electrical parameters a it's a obviously a mile off in many ways.
I won't describe the why as I don't want help with their R&D. but I'll suffice to say that you don't need the blueprints or access to AKG to reverse the ck12, although it would make the process much more expedient and and infinitely easier.... You do however need an extreme level of attention to detail and persistence to crack the many layers Ck12 code. I can see why AKG gave up on it as it's not built for mass production, but rather sonic perfection.

Yeah they're fantastic capsules. I thought about putting yours or Ben's in my C414 B-ULS, but the prices on the mic have gone up so much in the last couple years (and it looks like they've even gone up a couple hundred since I bought mine last August). The only thing stopping me is it feels like I'd be "ruining" a good mic because I do like the B-ULS a lot, it's just a bit too dark on my voice I think (it could probably use a cleaning too). I don't know how well the brass CK12 would do on spoken word unless it's tuned to be flat (or a slight lift).

I feel like I'm one of the rare people who really love a C414 on the voice.

 

[wlinart]

Here's a thought, maybe these capsules are a prototype for another manufacturer (for example 3U), which were rejected and are now sold anyway?

 

[Icantthinkofaname]

The diaphragm is 4 microns thick. Here's the image of one of the backplates facing the diaphragm. Unfortunately diaphragm is not glued so i couldn't tell how it was tensioned, but if i go by measurements too high. After the re-skinn at right tension FR started looking much better.

Much better as in it became usable, or it's still unusable but not as bad?

 

[kingkorg]

Much better as in it became usable, or it's still unusable but not as bad?

Still unusable, diaphragm tension is least of problems with this capsule.

 

[Khron]

As with so many other things - it's how you use it (?)...

 

[ubxf]

Still unusable, diaphragm tension is least of problems with this capsule.

Thanks for taking one for the team and spending time to analyze and share the results.

 

[kingkorg]

As with so many other things - it's how you use it (?)...

Nope unfortunately. The tuning system in CK12 is nightmare. It's not like other capsules where you have different flavors, and just go for certain sound.

The issue here is that you have to nail both cardioid pattern, and frequency response, and than in the end make sure the capsule forms omni and F8 according to specs once in circuit.

Both diaphragms have to be nailed within 3% of capacitance. Output and tension have to be matched. <5 microns tuning window. That's like thickness of the diaphragm. I feel if i just blow against it i could throw it off.

And the worst thing is if you don't nail all the aspects the capsule is basically unusable, unless you use it for special FX.

 

[Khron]

By "it" i meant the entire tuning of the capsule.

 

[Marik]

Nope unfortunately. The tuning system in CK12 is nightmare. It's not like other capsules where you have different flavors, and just go for certain sound.

The issue here is that you have to nail both cardioid pattern, and frequency response, and than in the end make sure the capsule forms omni and F8 according to specs once in circuit.

Both diaphragms have to be nailed within 8% of capacity. Output and tension have to be matched. <5 microns tuning window. That's like thickness of the diaphragm. I feel if i just blow against it i could throw it off.

And the worst thing is if you don't nail all the aspects the capsule is basically unusable, unless you use it for special FX.

One of the main problems was very broad machining tolerances. We were measuring front and back of the original brass CK12 and the dimension differences were as much as 100um (0.1mm!!!)... I am not sure why... perhaps they did not have precise enough equipment, so were using fine threaded movable pieces to compensate for that...

With modern CNC machinery that would've been piece of cake to get perfect repeatability. In this case I'd redesign the capsule so that all the cavities and chambers were machined into the backplates.... lots of R&D, though...

Best, M

 

[GabrieleP]

It's hard to get everything right when launching a product. Didn't you have problems with shorting backplates and wrinkling membranes lately?

From measured specs looks like we (they?) are quite far from "everything right".
I can't help asking a stupid, gigantic question: what for?
If you think this capsule has been out for 70 years now, you really can't think of this as the launch of a product. Come on... there's (at least) one single man who has learned to build this with his own hands. I mean...
What for?

 

[McIrish]

I have no insites to add to this discussion but wanted to say that this (and the locked thread) are fascinating. Such a wealth of knowledge here.