Microphone problem: collapsed capsule?

Hey guys! I have had a Behringer B-2 Pro for a long time, the other day I thought it wasn't getting the love it deserved so I took it out of its case to record some vocals and guitars. It worked perfectly on the guitar. The problem is, when the singer gets close to the capsule, it makes a deep whooshing sound and the whole output of the mic fades out. When the singer finally shuts up, a few seconds later the sound (of lack of sound, therefore i mean the ambience) fades back in, in a fashion similar to the fade that takes place when I switch the polar pattern.

From what I gather (I'm not a mic expert, just know how to use them ) it seems like the moisture from the singer's breath causes condensation on the diaphragm or something. I opened it, and there's lots of particles/dust on it.It used to be in a smoking studio back when it was used a lot, so I'm guessing the cap is done for. Can I just replace the capsule? I have heard it's a "custom Behringer" one, so there are no replacement parts for it, I'll have to go with a different one. I think it's a shame to throw the rest of the mic away. What do you guys think? Is a capsule replacement worth it? How should I approach the purchase of a new one? Is there something in particular I should watch out for (haven't done this before)?

Thanks for your time!

Not a collapsed capsule... moisture from breath, condensing on the capsule as if you breathed on a cold beer glass, for example.

If the capsule is dirty, it exacerbates the problem due to the hydrophilic nature of the deposits, which causes it to hold the moisture bridge.

Keith

SSLtech said:

Not a collapsed capsule... moisture from breath, condensing on the capsule as if you breathed on a cold beer glass, for example.

If the capsule is dirty, it exacerbates the problem due to the hydrophilic nature of the deposits, which causes it to hold the moisture bridge.

Keith

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Thanks for your reply, Keith. So the dirt is actually causing the break-ups in sound. Lots of singers sing close to the mic, only now this is happening, so it is obviously not normal. Can the capsule be cleaned or it has to be changed? What can I do? (I am a DIY-er, I just have zero experience when it comes to mics).

Some kinds of capsules are more prone to this phenomenon than others. Dirt like you mentioned doesn't mean that the capsule is bad. It may need a cleaning. I've cleaned a couple of my capsules with a cotton swab (very, very gently) with the very lightest pressure so that the swab was barely making contact with the capsule. I can't remember if I used isopropyl alcohol or purified water. You just don't want to leave any deposits on the capsule (like minerals from the water).

Alternatively you could just try to make do with it the way it is now. You are using a pop filter? I find that helps a lot with moisture problems.

I detect a difference in terminology here - it is the polarisation voltage that is 'collapsing', not the tension of the diaphragm - but the same word is used for both phenomena, hence the confusion.

If your capsule is centre-terminated, the good news is that the dirt causing the problem is in the un-sputtered region at the edge, which is far easier to clean than the rest of the diaphragm because you don't need to worry about the gold coming off.

As yosh says, you do need a very very light touch though  - a very fine artist's brush (a sable brush, you can find them in some model shops) is a bit safer than a cotton swab because you have a lot more control over the contact pressure, and you need to make sure that no water seeps under the diaphragm mounting ring or it could end up trapped behind the diaphragm (with disastrous results). So don't use too much pressure - it will create a gap at the edge of the ring that could allow moisture to seep under - or too much water, because it will run uncontrollably. If you can avoid even touching the mounting ring with the brush, so much the better.

At the end of the day Chinese capsules aren't expensive, so you can experiment with this one and if you ruin it there will be someone here soon enough that could sell you another. 

Thanks, guys! I (tried to) clean it today, I thought I had nothing to lose. I used distilled water with cotton buds. Unfortunately, some of the gold was removed (very little, actually) in the front diaphragm. I did much better on the back. The problem did not go away completely, but now it is manageable. The mic works perfectly with a pop shield if a reasonable distance is kept. I think I will use it until it gets worse again, then I'm going to use it solely for instruments or replace the capsule. Thanks a lot for your help! ;D

ytsestef said:

I used distilled water with cotton buds.

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NOOOOooooooooooooooo!   
Fine paint brushes

http://www.groupdiy.com/index.php?topic=22287.0


Used this method many times .......
Thanks Keef
The best capsule cleaning guide around