The Basics of Video Microphones

The microphones used to capture sound for video productions are a pretty deep topic, however, the basics are fairly simple, and that’s what I’m going to cover in this blog post. If you’re not in the mood to read, I also cover all of this information in the following video:

I’ve written about on-camera microphones a lot on my blog, however, for the most part, they’re not very good tools for sound capture in video. They’re simply an upgrade over the built-in mics on a camera. The big problem with on-camera microphones, such as the Rode VideoMic Pro, is that they’re on top of the camera—far away from the action. Microphones need to be as close to the sound source as possible, which brings us to our first pointer:

Pointer Number One:
Microphones need to be really close to the sound source

By “close” I mean 12 to 18 inches, and sometimes even closer. This pointer mostly applies to capturing dialog, but it’s such an important thing that you should always keep it in the back of your mind.

So, if your plan is to stick a little shotgun on top of your camera and be done with it, the chances are your footage won’t sound very professional, especially if someone is speaking to the camera. Using a boompole to get the mic closer is a must.

Similarly, if your plan is to mount a portable digital recorder on top of your camera, and attach it to the camera’s mic input with a Sescom cable, and then use the built-in mics on the portable digital recorder as an on-camera mic, the same pointer applies. (If that sounded confusing, watch the embedded video, this technique may be a little clearer). If you’re using a Sescom cable, you really should be using the recorder as an XLR adapter for the camera. You really need to get the mics closer.

A great way to get your microphone close to the action is to use a C-Stand, a Boom Cradle and a Boompole. A C-Stand is a heavy duty stand that can be used for tons of different things in video production. If you don’t own any of these yet, you may as well just go ahead and buy four of them right now. Anyhow, this combination of gear (C-Stand, Boom Cradle and Boompole) are what I use on set to get the mic right over the head of the on-camera subjects. It works really well.

Pointer Number Two:
Use more than one microphone

If you read the section where I stated that using a boompole was a must, and you said forget it, I’ll just use a lavalier, your audio won’t sound as transparently natural as it could.

Using a lavalier is a good idea. It could be a wireless Sennheiser G3 system, or maybe a wired Tram TR50, but either way, these little mics tend to sound pretty good because they’re usually within 12 to 18 inches of the speaking person’s mouth.

However, if a lavalier is the only mic you use, you’re taking a risk. People tend to speak with their hands, and you never realize how often they drive home points by emphatically touching their chest until you record them while they’re wearing a lav mic. Having a second mic on a boompole over their head does a world of good. When they inevitably smack the lav mic several times midway through a sentence, the boom mic will capture clean audio. However, this may require you to use a Beachtek or a juicedLink box in order to expand your number of mic inputs.

Pointer Number Three:
Avoid using shotgun microphones indoors

I’ve been driving home the fact that it’s always important to use a mic on a boompole in order to get it close to the sound source. This is true, however, when you’re capturing dialog indoors, using a mic called a “hyper cardioid small diaphragm condenser” is a much better choice, because it sounds more natural than a shotgun does indoors. Why? Shotgun microphones are very directional, so they pick up sound very differently than our ears do. As a consequence, they capture an unnatural amount of sound reflections from the floor, walls and ceiling. The result is that dialog recorded indoors has a subtle unnatural echo.

The list of hyper cardioid microphones that professional sound people use isn’t terribly long. The best choice on a tight budget is an Oktava MK-012, the next step up is the Audix SCX1/HC. The Audix is a sweet sounding mic that was made in the USA. The Audio-Technica 4053b is the next step up, and from there the price shoots through the roof. One of the most popular choices for professional location sound people is the Schoeps MK41.

Situations do arise where it’s okay to use a shotgun indoors. Sometimes you’ll need to use one on a really wide shot, when you can’t get your hyper close enough to the sound source. Other times, in kinds of certain rooms, the shotgun will just sound better. Use your ears. Remember, these are pointers, not rules. Okay… this next one is more than a pointer. This one is a rule.

Rule Number Four:
Always use extra wind protection outdoors

The best mics for use in video are all very sensitive, and as a consequence, they’re all prone to suffering from wind noise, so additional wind protection is a required purchase. The spongey foam windscreen that comes with most microphones doesn’t diffuse rushing air well enough for outdoor use.

Since shotgun microphones are primarily used outdoors, buying additional wind protection for them is  a must. There are fluffy and dense windscreens available that are sometimes referred to as “Softies,” which aren’t terribly expensive. However, when you need to use your shotgun in really windy locations, the best tool to use is a blimp.

Even tiny lavalier microphones suffer from wind noise outdoors, so little fluffy windscreens, such as Remote Audio Micro-Cats, are used on them as well. And now that we’ve arrived at these tiny balls of fluff, we’ve reached the end of this article. Thanks for reading!