Cleaning LDC mic

[maskedwarrior]

Hi there, I'm sure one of my mics would benefit from a clean as I've noticed it's lost its 'sparkle' a bit.

Is there a guide on here to do it safely and properly?
Tony

[Hugh Robjohns]

A dirty capsule doesn't normally affect the 'sparkle'. It tends to make the mic noisier.

H

[maskedwarrior]

Thanks Hugh.

Oh that's interesting. I had just assumed, as there would tend to be more mass to a dirty capsule, it would be less responsive at the high end because it would take comparatively more energy to move it at faster frequencies... Am I misunderstanding how sound energy transfers?

Is it that all frequencies are effected equally, hence a less efficient, more noisy mic?

Would love to know a little more behind this.
Tony

[Hugh Robjohns]

I had just assumed, as there would tend to be more mass to a dirty capsule, it would be less responsive at the high end because it would take comparatively more energy to move it at faster frequencies... Am I misunderstanding how sound energy transfers?

What you say is valid, but it would require a heck of a lot of crud on the surface or the diaphragm to add significantly to its mass, and unless you're in the habit of spraying partly -masticated Chinese food directly onto the mic diaphragm it's not likely to be a major problem.

However, any surface contamination -- whether Chinese food particles, cigarette smoke, or whatever -- will tend to trap moisture and cause a partially conductive bridge to the capsule frame. This will allow the static charge to leak away, causing audible rustly noises and potentially reduced sensitivity.

So if the diaphragm is contaminated 'frying eggs and bacon' type noises are the more normal indicator of a problem, rather than a lack of 'sparkle'.

The latter could be caused by degrading impedance converter circuitry components, or possibly degraded wind-shielding material (of foam rather than metal gauze). Or perhaps even a stretched diaphragm... but more likely is just greater familiarity with its sound character.

Cleaning the diaphragm is not something I'd recommend a novice to try, and it's rarely needed anyway. If the mic is a decent one, and you are concerned about the loss of 'sparkle' then I'd recommend returning it to the manufacturer to be checked over.

H

[Dr Huge Longjohns]

unless you're in the habit of spraying partly -masticated Chinese food directly onto the mic diaphragm

You might be doing a cover version of the Smiths' This Chow Mein Man?

[maskedwarrior]

Wow. I get it now. This is certainly the kind of intelligent & thoughtful response I've come to expect from this place, in spades too. My thanks to you Hugh. You totally scratched my ignorance itch there.

Tony