mic windcover

Protecting microphones from the wind

Wind is soundless, but the sound of wind as it moves across various surfaces can be one of the more interesting things to record in a soundscape.  However, wind rushing across a microphone can destroy a field recording.  A light wind can be filtered out using a high-pass filter, but if you wanted to include the deep rumble of thunder, for example, even light filtering can take the heart out of a recording.

Most “pro-sumer” recorders and many mics come with a piece of foam to shield the mics from the wind.  These are really only good indoors.  In general, you need to keep the wind off of the mic capsules, and this can be done in several ways.  Some options can be quite expensive, and the Nature Recordists group often referenced DIY alternatives, so that’s where I started.  However, if you don’t want to make your own, fur covers from Rycote, Rode, and Sennheiser are reportedly quite good.  There are a number of cheap knock-offs from China available now, but they are reportedly inferior.

The basic concepts

You need to keep wind off of the mic capsules.  This can be done using foam covered with fur, or using a cage to hold a fur cover off of the mic.  The big furry sausages at the end of boom poles that you see the sound guys using in video production are examples of these cages (known as zeppelins or blimps).  Most of these also incorporate shock protection, as most mics are sensitive to handling noise.  Other materials can also be used to cut the wind, for example, lycra or even mosquito netting.  Both of these need to be held away from the mic capsules.  Because wind may create noise as it passes over the surface of these materials, it helps if they are covered with something that literally breaks up the wind, such as fur or another soft fluffy material.  The longer the fur, the greater the wind protection.  Depending on materials used, the particular microphone, and the recording conditions, it may take more than one form of wind protection.  If a fur cover isn’t completely cutting it, putting the microphone in a small “tent” of netting (tulle or mosquito netting) can help a lot.

The simplest forms of serious wind protection include a fur cover over foam that surrounds the mic.  Some examples of these include Auray WSS-2014, K-tek fuzzy slip-on, Rode WS6 deluxe, Rycote softie, and Sennheiser MZH 600:

Professional systems include a shock mount, a zeppelin, and a fur cover. Rycote, in particular, makes modular systems so you can get each component, even different parts of the zeppelin, individually.  Some entire systems include K-tek zeppelin, Neumann WKE 81, Rycote Windshield kit 2, Sennheiser blimp system, and the Shure A89LW.  Most of these come in different sizes for different sized microphones.

Note that those systems are for shotgun mics. If you are using stereo mics, things get more complicated. But a few manufacturers do make blimps that encompass the whole array, including Rycote stereo extended ball gag, Rycote stereo windshield kit AE, Rycote stereo windshield kit AD, Rycote stereo WS 4, and Schoeps WSR ORTF.  Another alternative is to use something like a Rycote baby ball gag on individual mics in a spaced array like ORTF.

 

One key element in wind protection is “acoustic transparency.”  Materials that cut the wind also tend to affect the frequency profile of the recording.  Fur tends to reduce high frequencies.  Sometimes this is advantageous, as it tend to make the recording sound less “hissy.”  But if you want to record something in the upper ranges, you need to be careful with fur.  If you get the chance to try out blimps made by different manufacturers, pay attention to not only how much the wind is calmed, but how much the outer covering might be muffling the sound.

You also need to be careful with some windproof fabrics, including windproof fleece.  These materials can muffle the sound.  Likewise, recording from inside a camping tent covered with a rainfly tends to muffle the sound.

What I currently use

I have done a lot of experimenting with different materials and fabrics.  For my Audio Technica AT2022 stereo mic, I created a large foam ball out of open cell poly foam, and covered that with fake “wolf” fur I got at the local fabric store.  I tighten the cover against the shank of the mic using Velcro.  I added extra padding inside the sleeve that fits along the shaft; for this mic it is critical to block noise here.  As long as I tighten the bottom enough, it works pretty good and has a nice sound profile.   I could have tried a cover that enclosed the entire microphone and shaft, but that would make mounting the mic on a tripod more difficult.  I use a similar wind cover on my EM 172 mics.

Foam

Foam ball, AT2022, and fake wolf-fur cover.

AT2022 inside its wind protection

AT2022 inside its wind-proof cover.  This allows the mic to be attached to a mic stand and tripod.  This type of cover should also work for a Rode NT-4.

For my shotgun mic, I borrowed from a variety of videos posted on YouTube about how to make DIY blimps, and created the worlds ugliest blimp out of hardware cloth, plastic rings from a plant nursery flat, window screen, PVC, and rubber bands.  I covered it with wolfy fur, and it bears a strong resemblance to a professional microphone.  It works quite well, with just a whisper of wind getting through.  I’m not sure if that is due to the construction or the fur cover.  But the blimp is large (15” x 6”, not counting the handle), and not easy to pack around.

I also made a modified blimp by using the foam that came with my Audio-Technica AT897, and fitting 2 rings of pipe insulation around it.  This creates an air space between the foam and fur.  I made a shock mount from a PVC T (2 1/2 in with 5/8 in threaded outlet).  I made a handle for the shock mount from a threaded piece of 5/8 PVC, covered with bicycle handle bar foam to make it easier to hold.  I covered it with camo tape, well, just cause.  I used rubber bands to support the mic and reduce handling noise.

Shockmount made from PVC and rubber bands

Shock mount made from PVC.

Shotgun mic inside the shockmount

AT897 in the shock mount, with its foam wind protection and added foam rings.

Finally, I sewed up another fake wolfy-fur cover, making sure it was snug over the front of the mic (so wind ruffling the fabric wouldn’t create noise).  I left it looser at the back to hold cables.   I lined it with lycra for added wind protection and to make it easier to slide over the foam-covered mic.  This setup works almost as well as my flimsy blimp, and works fine in a light wind.  Its also much more portable and stowable than a blimp.  But if you are going to be working in high wind a lot, I would recommend buying a Rode or Rycote blimp.  I think they could handle both the wind and wear-and-tear of field work better.

Shotgun mic with shockmount and wind protection

AT897 shotgun mic with its shock mount and wind protection.  Sony PCM-M10 for scale.

Additional sources of noise

In addition to wind hitting the mic capsules, you also have to worry about the effects of wind on cables and tripods. I use Velcro cable ties to snug the cables to the tripod.  Tripods can “sing” if the wind hits them just right; supposedly carbon fiber tripods are much quieter.


Last modified November 17, 2015.

 

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