Intro from Jay Allison: Zeppelins, Blimps, Softies, Dead Cats... you know what I'm talking about. Jeff Towne has prepared a ridiculously detailed examination of WINDSCREENS. He analyzes which screen for which wind, tests various models, offers audio comparisons (in the wind!), and makes recommendations for preventing and fixing this common problem. You need this.
Mitigating Wind Noise
In the course of conducting interviews and collecting sound for audio documentaries, you’re likely to eventually need to protect your microphone against wind.
If you ever record outside, you’re bound to encounter at least a light breeze, perhaps a more serious wind. Either one can cause problems with microphones. And even if you’re working exclusively indoors, you might need to be concerned about a microphone’s wind sensitivity, to avoid problems from ventilation systems, or from moving the microphone quickly, especially if the mic is mounted on a boom pole.
There are many approaches to mitigating wind noise, some of them cumbersome or expensive, others customized to the needs of specific disciplines. We’ll take a look at some solutions that are relatively affordable, and easy to use by reporters and producers working on documentary-style sound collection. Nature recordists, sound-effects collectors and film sound crew might have different priorities, but we’ll focus on recording voices and general ambience, with commonly-used reporters’ microphones.
Most wind protection works by creating a zone of still air around the microphone, while maintaining audio transparency. At the most basic level, this can be achieved by placing a foam cover over the end of the mic. The foam creates a permeable barrier that slows or blocks wind around the mic. But a small amount of foam won’t stop serious wind, and too much foam will muffle the sound, so for a truly effective solution. more complex structures are required. Some combination of foam, air, and fake fur (which is strangely effective), can tame light-to-moderate winds from reaching the microphone diaphragm and causing bassy rumbles and other audio distortions.
A simple furry cover that slides over a foam windscreen can tame moderate winds. Thick layers of coarse open-cell foam, often paired with fake fur, can create a still air zone around the mic without muffling high frequencies too severely. And more elaborate structures, often called zeppelins or blimps, suspend the microphone in the middle of a large airspace, which is in turn protected by mesh and fake fur.
For many years, elaborate wind protection was very expensive, usually costing $600 or more, but recently, even large zeppelins from mainstream manufacturers have become more affordable. There are still plenty of devices that cost a lot of money: lightweight, elegant blimps from Cinela, new designs like the Cyclone from wind-protection pioneer Rycote, or products built for specific microphones or mic arrays. We’re going to focus on some reasonably-priced solutions, from Rycote, Rode, Bubblebee, and a very affordable blimp from a video gear company called ProAim.
You might have noticed a fourth zeppelin in the title photo, with a dark-colored fur covering. That is a smaller K-Tek Zeppelin made for the Sanken CS-1 short shotgun microphone. I’m not including that in our comparison because it’s a different microphone from the others, a different blimp design, and K-Tek doesn’t seem to be making zeppelins anymore.
It’s also important to remember that the particular microphone makes a difference: directional microphones are more sensitive to wind noise than omnidirectional mics are. Audio reporters are fond of shotgun microphones for their focus on specific sound sources, and rejection of extraneous noises, but their design makes them especially troublesome in the wind. In some cases, an omnidirectional mic might be a better choice. They are inherently more resistant to wind noise, so if you’re having a problem with wind, perhaps you should rethink the mic you’re using. The best answer might be to use an omnidirectional mic, and just move in closer to your subject. But even with an omnidirectional mic, you might find that you still need some defense against the wind.
For some reason, the world of wind protection is especially prone to weird, and sometimes macabre, names for its devices. The furry covers for mics and zeppelins, which the Rycote company calls “Windjammers” were informally nicknamed “dead cats” or “dead rabbits” or even “dead wombats” in many professional sound departments. The Rode company formalized that convention by officially naming their furry covers with those names.
Rycote, the industry leader in wind protection and vibration isolation, for some reason calls their small zeppelin-like devices “baby ball-gags.” (Be careful when googling this term! I’d recommend always including the word Rycote in such searches.)
For the sake of clarity, we’ll use Rycote’s term “windjammer” for a furry cover; the more generic term “wind shield” for a thick, coarse foam sleeve surrounded by fake fur, and “zeppelin” for the large blimp-shaped structures that suspend the microphone inside a large airspace, often covered by an optional windjammer.
We set up all of the zeppelins with Rode NTG2 short shotgun microphones inside, side-by side, outside on a windy day, recording the mics to separate tracks on a Sound Devices MixPre10T, with no high-pass filtering. We also placed an anemometer next to them, to monitor the actual wind speed. (We also tried using an electric fan indoors, for a more consistent, predictable kind of wind, but all the fans we tried were so loud that it made it hard to hear any distortion, or lack thereof.) It happened to be a very windy day when we did this test, with winds consistently in the 8-10 mph range, with gusts as high as 19 mph. This conveniently revealed the capabilities of the different wind protection devices. Most of them were pretty effective at the lower end of those wind speeds, and none of them could completely quiet a wind gust in the 15-19 mph range. We were surprised to discover that there was not a huge difference between the various comparable devices, despite differences in their dimensions and materials: all three blimps behaved fairly similarly.
The smaller “wind shield” devices, such as the Rycote Softie, and the Bubblebee Spacer, also had similar levels of effectiveness to one another, with the exception of the Rycote Super Softie which was notably more effective than the other two. But even a simple Rode “Dead Cat” furry cover over the stock foam windscreen did an unexpectedly decent job.
In all cases, we could still hear the wind, and usually got some significant rumbles in the higher gusts, but we still got useable sound. The low-frequency rumbles could be mitigated with equalization later in the production process, or could be reduced at the source, by using low-cut filters on the microphones or recorders.
The largest differences among the blimps came down to the fit and feel of the construction of the devices themselves. The Rycote Super Shield, despite being less expensive than most Rycote Zeppelins ($350) felt very solid, and seemed like it would last a long time. The Lyre microphone mounts do a great job of isolating the microphone from vibration, and seem much more durable than elastic suspensions. Opening and closing the zeppelin, to install or remove the microphone, was a bit of a challenge at times. It takes a very firm twist to open or close either end of the blimp, which sometimes felt like something was going to break — but when assembled, this blimp was very quiet and secure, and seemed like it would last a long time.
As with all the zeppelins, adding the furry windjammer improved the performance noticeably. This model of Rycote ships with the windjammer, it’s not an extra option. That cover is very high quality, and it even comes with a brush, to keep the fur from tangling and matting over time, for maximum effectiveness.
The Rode Blimp ($300) is physically a little bit larger than the Rycote Super Shield, and it too feels serious and professional, although it’s not quite as tight and solid-feeling as the Rycote. Even so, it will surely last for a long time if used carefully. I bought mine several years ago, so it has an old-style elastic mic suspension, which is holding-up fine so far, but newer Rode blimps feature the Rycote Lyre suspension points, which are more durable, and quiet. It’s nice to not have to worry about broken elastic bands. The Rode blimp also comes with a high-quality furry windjammer that fits snugly over the blimp, and greatly improves the rig’s wind defense.
The ProAim Blimp is significantly cheaper than the others ($115) and it feels like it. It’s thinner in diameter, the mic suspension is supported by tiny, fragile elastic bands (I managed to break two of them in one day, despite trying to be gentle while installing the microphone. Thankfully, the blimp shipped with plenty of replacement elastics.) The pistol-grip handle is harder to adjust smoothly, This blimp just doesn’t feel as solid as the other two, and the (included) furry cover has shorter hair and a looser fit. The cover closes with zippers, which could potentially cause rattling in gusty wind. So it was surprising to find that it had similar effectiveness to the other two blimps, in terms of wind protection.
This blimp did seem to color the sound a bit more than the other two, but not so severely that it would present a big problem. A little EQ at mix time would fix that up. While the other two blimps seem much more durable, it’s nice to have an option at a much lower price point (less than half the price of other blimps) that can still do the job if handled carefully.
In moderate winds, 5-8 miles per hour, all three blimps, with their furry covers, did a good job of reducing wind noise so that the microphones were not affected negatively. In stronger gusts, 15-18 mph, all three did suffer from some rumble, but even that noise was manageable, the mics did not overload or distort, even at a flat EQ setting (no low-cut filter engaged).
Predictably, all three zeppelins had their best wind resistance with the furry covers on, but even without that fur, the bare zeppelins offered an improvement over other forms of wind protection, even the wind shields described below. That’s likely due to the airspace around the mic that you can only get with a large structure like a zeppelin. And that airspace is crucial, so even though it seems counter-intuitive, the zeppelins are more effective without a foam windscreen on the mic itself, because the bare mic has a larger dead airspace than it would if it had a foam, or furry cover on inside the zeppelin.
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When a Zeppelin is Too Much
A step down from a full-on zeppelin, several companies make something generally called a “wind shield.” Rycote calls it a “softie,” which is basically a thick layer of open-cell foam, surrounded by either a furry cover or special fabric designed to have similar acoustic properties. These wind shields have a specific diameter hole in the center, and a depth that corresponds to the length of the microphone, so you need to make sure to get the right version for the microphone you’re using. Most shotgun microphones have a diameter of 19mm, but vary in length, so be sure to check your mic before getting one of these. Because of their design, they’re only suited for cylindrical mics, not ones with bulbous heads, like an RE50, or SM58.
This type of wind shield is less cumbersome, and less expensive, than a zeppelin, but they offer less protection in high winds. These wind shields protect the most sensitive part of the mic, but shotgun microphones tend to have some sensitivity at the back of the mic, and not being surrounded by still air on all sides, reduces the effectiveness compared to a zeppelin. That said, this level of wind dampening could be sufficient in moderate conditions.
Despite the fairly similar designs, we actually found some significant differences in performance. The design of the Rycote Super Softie ($130) seems to reduce the bassy rumble caused by wind.
It seems unlikely that the exterior fabric is quieter than the fake fur used on the original Softie ($100) so perhaps it’s the aerodynamic shape. Or maybe both. Although there was a bit more sonic coloration with the Super Softie, that was overwhelmed by the better rumble reduction. The fabric will require less maintenance than fur, and might be more durable.
The Bubblbee Spacer ($200 for a kit with two wind covers) looks like a cross between the old and new Softie designs, but in its bare state, it doesn’t offer too much resistance to wind — and it’s not designed to — the basic spacer is meant to be used indoors on a boom mic, to guard against wind noise form quick booming movements. For outdoor use, they sell optional long and short-haired furry covers. In the heavy wind that we encountered on the day of testing, even the long-hair cover left the Bubblebee system a little overwhelmed, but it was an improvement over no cover, and would probably do fine in lighter winds. And it’s nice to have a modular system that can adapt to varying conditions.
Surprisingly, one can also get decent wind protection by simply sliding a furry cover over the foam windscreen that comes with all shotgun mics. Rode’s “Deadcat” cover ($40) or Rycote “Windjammers for Foam,” are designed to slide on easily, but fit snugly, over the standard foam wind cover that’s provided with the mic. There’s no large airspace, like a zeppelin creates, and no large-cell open-cell foam like the softie-style wind shields, yet the combination of the two covers is surprisingly effective. It won’t provide as much protection as a zeppelin, or even a softie, but it’s close, and relatively inexpensive and easy to pack. As long as you don’t need to record in high winds, something simple like this is easy to pack, and simple to slide on.
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Are You Using the Right Mic?
Before jumping through all these hoops, trying to tame the effect of wind on these very wind-sensitive mics, it’s important to ask whether you’re using the right mic in the first place. With increasing directionality comes increasing wind-sensitivity. Omnidirectional mics are relatively resistant to wind. That said, they’re not impervious: if the wind is strong, you’ll still get some whooshing sound, and maybe some low-frequency rumble, as wind passes over the microphone. So, if you expect to be out in blustery weather, or subject to wind on a moving boat or vehicle, an omnidirectional mic is a good place to start, but you may still need some additional protection. A simple foam windscreen is provided with most mics, and that’s a decent start. But if that’s not enough, you may need additional gear. The Electrovoice RE50 is a very popular reporter’s mic, and even off-the-shelf, it’s pretty good in bad weather. Most times you see TV weather reporters being buffeted by wind, rain or snow, they’re probably holding RE50s. The omni pattern is part of it, but Electrovoice also built in some good shock absorption in the handle, and some additional wind (and P-Pop) resistance into the head basket.
The shape of the RE50 (and many hand-held reporter’s microphones, as well as some stereo mics, Ambeo mics, and others with a bulbous head) doesn’t allow them to slide into a Sofite-style windscreen. And a zeppelin isn’t really convenient for stand-ups and interviews. But Rycote makes a device that’s kind of like a small zeppelin, that fits tightly around the head of the microphone. Despite a rather unappealing name, the “Baby Ball Gag” ($120) is actually a very useful piece of kit. It functions in the same way as a zeppelin, creating a zone of still air around the microphone’s capsule, but in a much smaller form. And for very seriously windy conditions, much like its larger relatives, it can be covered by a furry windjammer ($65). That combination of an omni mic, the airspace created by the Baby Ball Gag, and the wind-taming of the furry windjammer, makes for a mic that’s almost impervious to wind. It’s a bit larger, and with the windjammer, weirder-looking, than a bare mic, but if you have to be out in the wind, it’s worth it for the protection, and sonic transparency.
Baby Ball Gags work by making a tight grip around the shaft of the microphone, so it’s important to select the proper size for your model of microphone. The RE50 has a relatively thick handle (25mm) but pencil-style mics usually require a smaller hole. No matter the diameter, it’s a tight fit. They’re designed not to slide on and off quickly, so plan ahead if you need to get one of these on or off your mic.
Fix It In the Mix
Some negative effects of wind can be mitigated by reducing the sensitivity of the microphone to bass frequencies. Most shotgun mics, and some other mics, have a bass-rolloff switch, also known as a high-pass filter (because it passes big frequencies, and stops low frequencies). Engaging that filter can eliminate, or at least reduce, the rumble caused by wind. It will thin out the sound you’re recording, but sometimes, if there’s a LOT of low-frequency energy coming from wind, or vibrations, reducing the sensitivity of the microphone to those frequencies can be much more effective than trying to EQ the sound later. Most field recorders also have a low-cut feature, sometimes offering several settings. Using those filters can be useful, especially if it helps you hear what you’re recording in real time, rather than hearing a lot of rumbling on your headphones and hoping that you’ll be able to fix it later.
If you can hear that you’re just getting low-frequency rumbles, and those sounds are not causing distortion on your recording, or triggering your recorder’s limiters, you’ll have much more control if you treat those rumbles later, when you’re editing and mixing. You’ll have a more reliable listening environment, and the equalization capabilities of your audio editing program have much more finesse than the simple low-cut on the mic or recorder. EQ will never make the wind noise go away completely, but rolling-off low frequencies can make it less intrusive, less distracting. Here’s one of the sound files form above, with a High-Pass EQ applied, at 150 hz, with a moderately steep slope. The sound does thin-out overall, but the wind rumbles are also much less intrusive.
The miraculous Izotope Audio Rx software has a “De-Wind” module that promises to help reduce wind noise, if it’s already embedded in your recording. However, I’ve been unable to get any significant reduction of wind rumbles without creating even worse processing artifacts. If you’ve had better luck, please feel free to share any advice about useful settings in the comments section below.
The best answer is to avoid the wind noise in the first place, rather than trying to fix it in the mix. If you can get close to your subject, perhaps you should use an omnidirectional mic, rather than a shotgun, or cardioid mic. If you do need to use a directional microphone outside, use the best wind protection that is practical. A furry windjammer slid over the factory-issue foam might be sufficient for moderate breezes. A Softie-style wind shield might be safer — we especially like the Rycote Super Softie. But if you’ll be in strong winds, you’d be wise to consider something more robust: a zeppelin if you’re using a shotgun mic, or any directional mic that would benefit from isolation on all sides. A Baby Ball Gag might be more appropriate if you’re using a handheld reporter-style microphone, or other small-diaphragm condenser mics.
There are specific zeppelins, foam covers and windjammers made for almost any microphone, and also for the built-in mics on popular hand-held recorders. Do a little research on the manufacturers’ web sites to make sure that you have the right version for your equipment, it’s important that foam and fur covers sit snugly, and that zeppelins have enough space inside, so follow the manufacturers’ suggestions, or measure your equipment’s dimensions carefully.
As always, it’s important to wear headphones, and monitor your recordings in real time, so you can make adjustments if the wind noise is too severe. Perhaps you can find another location. Try the other side of a building, or simply turn your body to block the wind. Ultimately you can’t completely silence the wind, your goal is to make sure that the wind does not ruin your recording. If it’s very windy, it’s fine if your recording sounds windy! But you don’t want gusts of wind to cause bass rumbles and other distortions that might render your recording unpleasant to listen to. Thankfully, one of the devices described above might help make your next outdoor recording sound better! There are new designs and materials being created for this purpose, and the prices for these accessories have been trending down, so there may be better solutions in the future.