Advice on humidity and microphones

[Lazy_Q]

I was working on sampling some of the background noises/ambience around my house, when I rememberd that microphones (especially condensers) don't take too well to moisture, and the humidity in georgia rarely drops below 90% from mid-may to mid-september. The air's nice and soggy this time of year especially.

The question is: is there a good way to do this? or in the experience of people here, at what point does humidity become a problem for recording? What kind of microphones do better in such conditions?

To the problem at hand I see three solutions (given my current setup)

1) use the MK012 matched pair and just don't take really long samples, and get it back in a dry environment pronto.
2) use the cheaper sony mid-side mic and don't take really long samples or
3) use the POS sony mic that came with my minidisc until it dies then toss it.

I'd rather not do the third one, since I believe almost any mic has a use for something, but it's an option.

[ahmedgarcia]

I use a computer mic on a stand with my MiniDisk. I go out after it rains and record the sound of cars driving over the ashphalt. Or I take a trip on the bus and back home. After an hour of recording I go home and there you go. I especially enjoy recording storms as they come it.

I still use the same mic the next time I go out. Never had a problem.

[I'm Painting Again]

i have taken very sensitive equipment into the central american rain forrest..if you pack it in a pelican case with that stuff that absorbs airwater you will be fine..take it out when you need it put it back when yr done..keep it out of the sun..those cases are air tight and water/dust proof and indestructable..small pelicases are really not that expensive..and will keep your gear like new forever..

[Meriphew]

I keep most of my mics on their stands in the vocal booth with a plastic bag loosely draped over the mic. I have a desicant packet taped inside each bag, and there's also a box of desicant inside the booth.

[inverseroom]

My home studio is in my basement, and the moisture wrecked a few things--a Mexican Telecaster, for one, and the keyboard contact strip on my Micromoog, which cost eight bucks to fix... so I got myself a dehumidifier from Sears, ran a hose into the drain, wrapped the studio in plastic sheeting and MR wallboard, and viola, it's dry. Try it, Hoss.

[Professor]

The biggest problem for you won't be the humidity, or even the difference in humidity, it will be the difference in temperature. You have noticed, I hope, that while water condenses on the side of your glass of iced tea it does not condense on the glass windows - unless you drop the temperature of the building interior (and the accompanying windows) past the dew point. So, I would venture to say that you will be safe provided you don't carry very cold microphones outside into the very warm and humid air. If you don't see & feel condensation on the outside of the mic, then there won't be any inside either (ideally).
I would recommend that you store your microphone of choice in a little box with the desicant (aka silica gel) packet inside at the same temperature as the recording. If your whole house is air conditioned and dehumidified, you might need to store the mics in the garage while you are gathering these samples. If they need to be stored in a cooler place, try raising their temperature (hold them, stick them in your pocket) before going outside. If the microphones are as warm or warmer than the air outside, you won't have condensation. If you see or are at all concerned about condensation, don't plug in the microphone for a couple hours.

When I was in music school in south Florida, I noticed that water would condense on my watch face if I took it off while practicing and then put it on as I went outside. If I wore my watch during practice, my body temp kept it warm and it would not gather any condensation.

As I understand it, condenser microphones and particularly those with pressure or pressure gradient capsules are the most susceptible to humidity, followed by dynamics, with ribbons being the least bothered. I'm not a microphone builder or repair tech, so don't take my absolute word, but I am fairly sure that is the case. Since your options are all condenser, you might as well just stick to temperature control.

-Jeremy

[Lazy_Q]

Gracias to all on the advice, esp. Professor and Sky_At_No_Noon. Sampling a rain forest sounds like too much fun. The only thing cooler (in my reccolection) is seeing the pictures of the guys working on 'Gran Turismo 4' sampling high end car engines (to which my response was "I WANT THAT JOB!", But I'd settle for just the sample set).

In any case, the quick follow up question is: where can I buy dessicant and pelican cases? (should have written down where to buy dessicant last time something like this came up).

[PatrickBrown]

Knock on wood. I'm in humid south Louisiana, and though some may say I'm mean to my mikes, I just leave them on the stands.
The temp is fairly constant, and so far, I've not had any trouble. It seems to me that some of these venerable old mikes found in studios have done duty for years, and even if put up, the amount of possible moisture they'd have collected from countless people singing into them would far exceed anything my 'in house' invironment could inflict on mine, at this young age in their lives.
I've not noticed anything, and I don't get any condensation on any of my other equipment.
It makes me kind of shy away from contantly pulling them off stands, out of shock mounts, etc., and handling them more that way, and constantly unplugging them, not to mention continual variation imposed by sessions with dessicant inside a box or pouch, and then outside again, with the humidity levels being constantly changed thereby. I probably ought to put a sock over them,,more for dust than anything, but that's not bad. When the equipment goes on, I think the subsequent warming by the gear burns off, or at least reduces ambient humidity, too. The humidity isn't that high in the house, I don't think. I have the AC on constantly in the other(next) room,,but not in the studio.

[dgochenour]

My studio sounds a lot like inverseroom's, and I, too, bought a dehumidifier and it does the trick.

One question though-- does anyone know if it can be too dry for mic diaphrams? My dehumidifier can be set digitally, by percentage humidity and I've been keeping it very dry.

Probably a silly question, but I've never known.

[I'm Painting Again]

Sampling a rain forest sounds like too much fun..

just being there was the best part i did have a stereo mic but was actually filming monkeys, crabs, and lizards..as a testament to those cases i mentioned..i had one tied to a raft on some serious rapids and we filpped over the rocks..not even a scratch on the outside..my friend jose said a semi-truck ran over his case and only the handle broke..

are you doing a piece of music using only sounds from around your house?

that sounds like much funn. that group matmos did an album with sounds of surgery check that out if your into that kind of thing..you probably already know it..

oh yeah pelican is the brand search the net and find the cheapest..you can get a size that will fit mics for probably about 50 bucks that sa guess..heres a site http://www.casesbypelican.com so you can get an idea of sizes and prices.

[Professor]

Glad to help Lazy. I'm not sure where you could buy those little silica packets retail, but you could probably try a local camera store, or just walk around the mall and ask a couple of clerks. You might even visit a higher-end department store and check inside the leather jackets or handbags.

Pelican is a brand name of waterproof cases. They are wonderful but also a bit pricey. Doskocil makes similar cases that are about half the price (though still around $60-80) and fairly close in quality. You might look at your local sporting goods store or better still a gun shop. Their websites are pelican.com and doskocil.com

As for that last question about things getting too dry for microphones, I don't know that you could get too dry. I mean you are never going to reach 0% humidity with a dehumidifier (unless you're in the desert already). When I think of the effects of dry climates, I could see rubber gaskets drying and cracking, and rubberized insulation on wires have a time, but the mylar and gold diaphrams and the ferrite magnets wouldn't have a problem. On the other hand, sound travels differently in dry air, so things might start to sound different if you get too dry - but I suspect you will not like the dry eyes or splitting wood furniture before that happens.

-Jeremy

[I'm Painting Again]

come to think of it..i used to work for a guy who was a video engineer..he kept the studio at a certain humidity level..with a meter..there was actually a humidifier blowing water into the air by my feet while i was editing..theres got to be some info about this out there..if i talk to him soon i will ask about it..i think he said some thing about certain electronics functioning best at a certain humidity level..

also if you get a pelicase and you bring it on a plane make sure the o-ring is open .. im told it can explode..

[PatrickBrown]

Doesn't extreme dryness help conduct static electricity better? I could see someone carrying a charge, and then touching a mike, and unloading that charge onto the mike.

[endofanera]

Doesn't extreme dryness help conduct static electricity better?

Absolutely. I would think that would be at least something of a concern; I know it is if one's working with computer components.

[omegatr0n]

In any case, the quick follow up question is: where can I buy dessicant and pelican cases? (should have written down where to buy dessicant last time something like this came up).

You can find silica gel packets at most camera stores, however, they tend to be overpriced. At arts and crafts stores, you can buy "Flower Drying Crystals", which is none other than 100% silica gel.