Soliloqueen's k87(k67) and k47 capsules

[MaxxDM]

I use fedex. It's usually pretty cheap but you have to pay whatever the import tax is when you receive it

oh.. ok, I asked for Fedex

 

[soliloqueen]

oh.. ok, why did I pay sales tax if I have to pay import tax?

you didn't

 

[MaxxDM]

View attachment 146038you didn't

Yeah, I just saw that, sorry

 

[MaxxDM]

So, I looked up an old post on another forum, where I had posted the frequency response of a 1952 mic, probably an early u47. I think I got this from Neumann info.

the presence peak in the earlier capsule seems to be around 9 KHz?

I also found an article from Wireless World from 1953, and the peak is at 8 KHz

So, it appears that the M7 was always changing, adapting perhaps to whatever was needed.

I do know, that, the German condensers were considered shrill, so there seems to have been an evolution, which led up to the relatively flat capsules made later on.

Maybe the ones Sinatra used, had the peak up in the 8-9 Khz region.

Capsules are traditionally designed bright for distant microphone technique, and close mic technique became more of the norm, so maybe that's why they eventually became flatter in response.

 

[MaxxDM]

I'm guessing that if they were able to get a 9 Khz peak on an M7 skinned with new PVC, it may have sounded considerably different than the way a K67/87 resonates on top.

 

[soliloqueen]

interesting. the bakelite rings themselves in the bakelite test capsules seem to have warped slightly, causing wrinkles in the diaphragm that are not from loss of tension or diaphragm slippage. i wonder why. reaction to the glue? off-gassing?

 

[MaxxDM]

Maybe residual stress from when it was manufactured?

 

[soliloqueen]

Maybe residual stress from when it was manufactured?

That's my thought. We did do CNC as opposed to hot punching it like Neumann did and plus, it's not actually Machining grade Bakelite either. well, this is why we do tests.

 

[micolas]

That's my thought. We did do CNC as opposed to hot punching it like Neumann did and plus, it's not actually Machining grade Bakelite either. well, this is why we do tests.

All my life I hated Bakelite. It is an unstable material in terms of mechanical, thermal, chemical resistance, it becomes fragile, brittle, sometimes it loses its dielectric properties. It was a nightmare for electronics. For decades it was used in electrotechnics, electronics, in the former Eastern European communist bloc. And now I have unpleasant memories of the Soviet components, parts, which contained Bakelite. The same situation in the field of household appliances or industrial uses.

 

[ZHOUJUN]

I found that the inside of the holes on the early Neumann back plates was very smooth, and some of the holes had a platform at the bottom. Those platforms should have been specially designed that way and were processed in several times to ensure that the inner wall was smooth and consistent. The internal smoothness of the hole and the size of the hole should have an impact on the reflection of sound waves. In many replicas, the inside of the hole is very rough. If you use modern CNC, it should be possible, but it is not very easy to maintain consistency, and the cost is also high.

 

[micolas]

I found that the inside of the holes on the early Neumann back plates was very smooth, and some of the holes had a platform at the bottom. Those platforms should have been specially designed that way and were processed in several times to ensure that the inner wall was smooth and consistent. The internal smoothness of the hole and the size of the hole should have an impact on the reflection of sound waves. In many replicas, the inside of the hole is very rough. If you use modern CNC, it should be possible, but it is not very easy to maintain consistency, and the cost is also high.

To obtain a very high quality of the surface of the holes, you must resort to more demanding technologies (rectification, honing, lapping, polishing). These mechanical processes require special equipment, tools, consumables, technologies, high precision, a special qualification of the workers and an impeccable technological discipline.
They are very time-consuming. Quality control becomes more complicated.
All this translates into substantial increases in production prices.

 

[MaxxDM]

I found that the inside of the holes on the early Neumann back plates was very smooth, and some of the holes had a platform at the bottom. Those platforms should have been specially designed that way and were processed in several times to ensure that the inner wall was smooth and consistent. The internal smoothness of the hole and the size of the hole should have an impact on the reflection of sound waves. In many replicas, the inside of the hole is very rough. If you use modern CNC, it should be possible, but it is not very easy to maintain consistency, and the cost is also high.

I would be curious to hear what the effects of this polishing of the holes are in practice.

 

[ZHOUJUN]

I would be curious to hear what the effects of this polishing of the holes are in practice.

I think they must have a role. These holes are hidden behind the diaphragm, and the inside of the holes cannot be seen from the outside. As a manufacturer, in terms of processing costs, they should not waste these unnecessary work. As far as I know, the position and depth of the holes on the back plate have an impact on the frequency response.

 

[paulster44]

How to order?

 

[micolas]

How to order?

Hi @paulster44 !

If you want to order Arienne capsules:
https://store.arienneaudio.com/13-microphone-capsules

 

[paulster44]

Hi @paulster44 !

If you want to order Arienne capsules:
https://store.arienneaudio.com/13-microphone-capsules

This is Soliloqueen capsules?

 

[micolas]

This is Soliloqueen capsules?

Yes.
Arienne Audio is the company of Ari aka @soliloqueen

 

[Roman B.]

I think it's worth mentioning, Ari's capsules are being delivered not only with a decent capsule holder, but also including a little "roof" to protect the capsule while bouncing around in the head basket, in case of an accident.

As I wanted to mount my K87 as high up in the head basket as possible, I was really happy to find that roofy inside the zip bag.

@soliloqueen Does this thing also have an audible/measurable effect?

 

[micolas]

I think it's worth mentioning, Ari's capsules are being delivered not only with a decent capsule holder, but also including a little "roof" to protect the capsule from hitting the head basket in case of an accident.

As I wanted to mount my K87 as high up in the head basket as possible, I was really happy to find that roofy inside the zip bag.

@soliloqueen Does this thing also have an audible/measurable effect?

The effect of the "protective hat" above the capsule is acoustically minor.Can't you do some measurements with pink noise?
Edit:I calculated in a later post the approximate minimum frequency at which protective hat can affect sound, and it places it well above the human audio spectrum. (>144KHz)

 

[Khron]

@soliloqueen Does this thing also have an audible/measurable effect?

I'd be surprised if it did. Or even if it does, it's way up in the ultrasonics, where the capsule's response is way down in the noise floor already...