Let's talk about capsule holders!

[rock soderstrom]

I'm currently looking into capsule holders and maybe for the first time designing and 3d printing one myself.

What is important for a capsule holder besides the actual function to hold the capsule safely? What do we need to consider? Does the shape play an acoustic role? What should be avoided? What is the ideal capsule holder?

My capsule has a diameter of 25mm. I have attached two possible variants.

The first one I would call standard, the second one is more often seen with smaller capsules. Why is the area around the capsule increased here?

Does the material play a role? Do you prefer hard or soft material?

 

[andYz00m]

Excellent topic! I’m curious about this as well. With all the variants of C12 U67 etc the mounts are different.

Would love to hear some comparisons if anyone has done that.

 

[k brown]

The two most important properties are vibration isolation (hence the rubber 'stumps' used in most big-buck mics, and a minimum of reflection/diffraction inducing surfaces in close proximity to the capsule.

To quote Elon Musk - "The best part is no part" - not possible here, but that's the acoustic aim; it should be as 'not there' as possible, but still hold the capsule securely.

Hard to do much better than those used in the classic Neumanns.

Though the post-less 4-point suspension in the 414 may be better; it would be an interesting test to compare that method with the Neumann rubber post, keeping capsule, electronics, body and head basket the same.

The 414 method is certainly trickier for DIY. Maybe you can buy that tabbed rubber ring as a separate part.

I was always intrigued by Sony's unique approach in C-37A; has the minimum surfaces near the capsule, but provides no vibration isolation; relies entirely on the shock mount built into the yoke (which makes sense, because that also gives the tube additional isolation).

 

[kingkorg]

You need to be carefull with capsule suspension with rubber and similar.

Røde did a really dumb thing with at least two mics, following the logic of using elastic materials to provide suspension. One is NT1 black, the Rycote style holder behaves like a 30-50hz oscillator even if you just touch the mic. Even worse with NT3, however they used internal foam pop filter that supports the capsule so you can't tell until you try the mic without the foam.

C37 seems best to me in every aspect. Maybe add thin layer of some damping material so it doesn't transfer mid/high frequency stuff.

Elam251 solution is great.


When using rubber, and plastic you need to be aware of it's electrical properties, so it absolutely doesn't conduct, even with age.

 

[k brown]

The C12 mount always struck me as the winner of the "How complicated can you make a capsule mount?" contest.

No denying it's legendary sound, but I don't think I could bring myself to put in the time and effort to DIY a mount that puts so many hard, reflective and diffractive parts so close to the capsule.

 

[Icantthinkofaname]

You need to be carefull with capsule suspension with rubber and similar.

Røde did a really dumb thing with at least two mics, following the logic of using elastic materials to provide suspension. One is NT1 black, the Rycote style holder behaves like a 30-50hz oscillator even if you just touch the mic. Even worse with NT3, however they used internal foam pop filter that supports the capsule so you can't tell until you try the mic without the foam.

C37 seems best to me in every aspect. Maybe add thin layer of some damping material so it doesn't transfer mid/high frequency stuff.

Elam251 solution is great.


When using rubber, and plastic you need to be aware of it's electrical properties, so it absolutely doesn't conduct, even with age.

A bit off topic but Rode's found ANOTHER thing to screw up in the new NT1. They ditched the flat capsule from the all black one and made it much brighter. There's an airyness that's almost NT1-A like.

The C12 mount always struck me as the winner of the "How complicated can you make a capsule mount?" contest.

No denying it's legendary sound, but I don't think I could bring myself to put in the time and effort to DIY a mount that puts so many hard, reflective and diffractive parts so close to the capsule.

God damn that looks terrible. The silver lining is that it might slightly reduce plosives. Maybe?

 

[k brown]

Well, that photo is of the back of the C12.

I just wanted show the entire capsule mount assembly.

 

[Gus]

I don't understand this forum some times

MS Vienna posted about mounts in the VM1 and TLM103
There are posts about the conductance in some holders I believe one of the first I read on the web was an Olvier post in the 2000s
Look at the C800G capsule environment

Don't just think mount, think the total environment around the capsule and possible acoustical coupling to the body that is often a tube and what is a tube used for in music. Why are some tapered and why are some round and what that can change.
Then think about how to damp the capsule if you want to damp it inside the grill. things like durometer, lenght of the rubber or what ever else you use. It has mass, damping and spring

Schoeps
Look for pictures of the different microphone like the CMV51 and 221 with added parts.

 

[soliloqueen]

Gus's bedside manner as always is a bit rough but as he says it is important to recognize that the capsule head assembly is a spring mass system from a materials perspective. When you ring the capsule, what happens? Think about buzzing a school ruler. What effect does the allowed length and how hard you press down have on how the ruler buzzes? Not only that, but it interacts further with the acoustic system of the microphone. Think of the location and stiffness of a bell attachment and how that affects how it rings. Where is the energy that's exciting the capsule going after it excites the capsule? How and in how many ways is it conducted to the capsule in the first place? Through what interactions?

 

[k brown]

Must not lose sight of what's really required to scale the Capsule Mount!

- Good shoes.
- Keep warm.
- Stay hydrated.
- Don't scale alone!

 

[aazaa]

Hard to do much better than those used in the classic Neumanns.

 

[rock soderstrom]

Thanks a lot guys for your info! Many of my hunches have been confirmed, some things were new to me or at least not so clear.

I think it's not bad (also for other interested people) to have all this in one thread, which will also be found well by the search algorithms in the future.

One more question about the position of the capsule in the grill. I assume that if there is enough space, a higher position(B) is generally better than directly above the "floor"(A). Right? Is there a correct height ratio to achieve the best acoustic position?

 

[rock soderstrom]

The first one I would call standard, the second one is more often seen with smaller capsules. Why is the area around the capsule increased here?

Just out of interest, what is the effect of increasing the area around the diaphragm with the holder? (second and third photo in the first post). Is this more due to stability or does it have an acoustic reason?

 

[Murdock]

Larger area around the capsule brings down the frequency at which pressure builds up. That means that the frequency which has the same wavelength as the boundary will double in volume (+6dB).
I think. Google pressure build-up or Druckstaueffekt in German.

 

[rock soderstrom]

Larger area around the capsule brings down the frequency at which pressure builds up. That means that the frequency which has the same wavelength as the boundary will double in volume (+6dB).
I think. Google pressure build-up or Druckstaueffekt in German.

I will do that, interesting. Thanks a lot!

 

[kingkorg]

Thanks a lot guys for your info! Many of my hunches have been confirmed, some things were new to me or at least not so clear.

I think it's not bad (also for other interested people) to have all this in one thread, which will also be found well by the search algorithms in the future.

One more question about the position of the capsule in the grill. I assume that if there is enough space, a higher position(B) is generally better than directly above the "floor"(A). Right? Is there a correct length ratio to achieve the best acoustic position?

View attachment 105490

Depends. A vs B will in general create deviations at different frequencies. But off the top of my head i would pick B as a better solution.

 

[k brown]

The other difference between A and B is intensity of the reflections. As the capsule moves farther from the base, I believe the reflections fall off the square of the distance.

 

[soliloqueen]

The ideal solution is obvious...

/J

 

[rock soderstrom]

The ideal solution is obvious...
View attachment 105501View attachment 105502
/J

Is that real or photoshopped?

The old boys approached the subject like this.


Model Gyraf giraffe

 

[k brown]

Is that real or photoshopped?

The old boys approached the subject like this.

View attachment 105503View attachment 105504

Except that we now know that semi-spherical heads are far from ideal, which is why neither Scheops nor Neumann makes any mics like that any more.

The distance from the body is good, though.