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Why You’re Getting Wind Noise

So I’ve seen post after post about wind noise, so I figured I’d just share all of my info in one place. As I’ve mentioned before, I’m a video professional and have worked with video and audio for around 15 years at this point.

In pretty much every case I’ve seen, the wind noise that motovloggers experience is caused by poor microphone choice.

Yes, I know we don’t have many options so people get the usual lav/lapel mic and shove it behind a cheek pad or cover it in fur. But my statement is fact. Lav mics aren’t meant for motovlogs.

Lav mics are designed to be clipped to a shirt/jacket and pick up a person speaking in a controlled environment from about 6″ to 12″ from their mouth. And motovloggers take this same mic and run it down the highway at 65 mph and expect it to pick up clean audio.

Let me explain why a lav mic is generally bad for this purpose, and why the foam you stuck on it is only minimally effective.

First, lets begin with a basic understanding of pickup pattern …

Lavaliere mics are generally cardioid or omnidirectional microphones. The image above shows a cross section of the “on mic” area of each … or where you get clean, natural-sounding audio. Imagine the images in 3D, where the center of a graph is the tip of the mic and the pattern shown rotates all the way around it.

As you can see, the omnidirectional pattern will pickup audio from any direction and the cardioid is focused on the 180* directly in front of the mic. This is great for a lav becasue when the speaker turns their head the dynamic range of the audio is maintained.

So, with that explained, let’s look at the actual mic options …

This is a standard form factor for a lav mic. Looking closely you can see open areas for sound waves to pass through uninterrupted on the tip and also on the sides. While great for a presentation, when you put this thing in 60 mph winds, those areas catch the air and if they don’t direct wind directly into the mic itself, they create turbulent vortices right beside it that’s picked up in your recording. Even if the mic is pointed right at your mouth with the wind behind it, the air will still catch on the sides and wrap around the tip and be picked up.

And then there is this kind of mic …

This choice is even worse with dual microphones exposed in all directions. There is literally no direction to face this thing that would begin to shield the mics from wind.

So, why can’t you just put foam or fur on it and fix the problem? Because that’s not what the foam is designed for.

Mic windscreens are designed to stop a stray breeze or breath from hitting the mic directly. When you increase that to 60 mph there is so much velocity it will make it’s way to the mic through any “standard” foam. Even professional shotgun mics with foam and fur will pick up a decent breeze on location.

You can get a super dense foam that could possibly stop the wind at speed, but you will do that at the expense of audio quality and volume.

Volume is a notable problem becasue the cameras we use are generally auto gain controlled, meaning that they constantly ride the input level to average a certain dB. When you make the mic less sensitive with dense foam, the gain is increased introducing signal noise and likely still picking up the wind that you are trying to get rid of, but more of a dull roar than the sharp hiss you’re used to.

The same goes for fur. It’s designed to stop low velocity wind and works better than foam as it’s more irregular. But it won’t stop noise from wind hitting the mic directly.

So, how do you fix it?

You get the mic out of the wind.

You can have some luck tucking the mic behind a cheek pad, and if successful you’ll hear yourself, but you’ll likely have a lot of high frequencies cut out and your voice will sound deep and boomy. Maybe you’re cool with that. Personally, I’d rather have my own clear voice.

To do that you need to keep the mic itself close to your mouth, unimpeded by dense layers of foam … and you need it out of the wind.

So, you divert the wind. That’s the best option. You can do this in several ways. If you have a full face helmet with ways to block wind in the mouth area, put the mic there and face it toward you. Close the front vent. If this isn’t working it’s likely that there are vortices swirling in that open space coming in from under the helmet and there is still indirect wind hitting the mic.

So, you can create a physical barrier of some type to shield the mic from the wind that’s still there. A small piece of plastic glued behind/around the mic will work fine for this. It should be a decent distance away from the mic in case it’s creating it’s own vortices which could be picked up.

Personally, I’ve been suggesting the Sena 20s mics to people with issues. I use a Sena wired mic from a SMH10R that I had to custom wire. The 20s versions are the same mics but have a 2.5mm plug that can be easily adapted to the common 3.5mm plug needed for action cameras.

I recommend these mics becasue they are engineered to reduce wind noise in our specific application.

Look at the design of the Sena boom mic. Notice the small opening and large plastic shield with tapered edges. This is engineered to divert wind coming directly at the back of the mic around it. And it does so far enough away as to not let any created vortices reenter the mic’s pickup area. The tapering on the edge reduces the turbulence created as the wind is diverted.

This mic can capture clean audio at speed from an open face helmet. Sure, Sena uses advanced noise cancelling technology, but they can only apply that to the audio that’s captured. With only one mic, you have to kill the wind noise to effectively clean up the voice because you don’t have a secondary audio stream to compare to and remove the unwanted frequencies.

And yes, the Sena mics come with foam windscreens. These are no different than the same ones I’ve said don’t work for other mics. In the case of the Sena application, they are there to reduce noise coming directly toward the front of the mic, like breath or a crosswind when you turn your head. If you look hard over your shoulder, the Sena mic will still pick up wind noise with the shift in direction.

So, all that to say that while foam and fur and position can help, the only way to actually cure the wind noise issue without sounding like you’re speaking from another room is to divert the wind around the mic. And there are mics out there specifically designed to do this. Maybe don’t reinvent the wheel and spend $25 on a mic designed for the job. It’s worth it.

 

Credit to: SalvageSV

 

Steve Galendez

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