When recording sound on location, a sound recordist must be aware of the microphones they will need in order to obtain the best possible audio on set. The two most well-known types of microphone for recording dialogue are mics mounted on booms (cardioid mics, or more commonly used shotgun mics, which have super or hyper-cardioid polar patterns); and lavalier microphones, also called lavs. We will almost certainly be using a combination of both of these microphones to capture the majority of the dialogue on location, and potentially some on-site foley as well. We would also like to experiment with boundary mics where appropriate, and in regards to atmospheres and room tone, I’d quite like to gather some stereo recordings, using either a single stereo mic or a matched pair of mono mics. Most of my research on microphone types has been from The Location Sound Bible (Viers, 2012), which I’ll reference at the bottom of this post.

The shotgun mic will provide the best audio in terms of quality, as it has excellent frequency rejection at the sides of the microphone, with a little sensitivity at the rear of the mic. The front of the mic is extremely directional too, depending on the length of the mic, so as long as the boom operator angles the mic correctly, dialogue and the surrounding room tone will sound excellent. In terms of all-round performance, Viers writes that the RODE NTG-3 and Sennheiser MKH 416 are the most popular, go-to mics, not least because they employ RF Bias technology, which affords the microphones excellent resistance to moisture. The length of the microphone is also something to take into consideration, as longer microphones have more phase ports and therefore have greater rejection at the sides of the mic. However, the size of the pickup area, the space at the front of the mic where sound can be picked up best, is much smaller and so it can be harder to record dialogue consistently well, especially if actors are moving around a lot.

Here you can see the range in sizes of shotgun microphone.

A shorter mic will probably be better, as all of the shooting will take place indoors, restricting the space available when booming, and it will give us some more leeway in terms of pickup area, as we are still learning how to boom properly. I think the Sennheiser MKH 416 would be best suited for our needs, as it is an excellent short shotgun microphone, capable of producing professional quality audio. Also, it fits into a Rycote Windjammer, which could be used to help deaden any wind noise or other unwanted audio when filming. Media loans has MKH 416s, and we would be sure to rent out carbon fibre boom poles, which are a lot lighter than their metal counterparts. This will let us boom for a lot longer without needing breaks, assuming we have done adequate research into booming techniques.

The Sennheiser MKH 416 and the Rycote Windjammer.

Lavalier microphones are the other type of microphone we’ll be using on set. Lavalier mics are named after the French word lavalier/lavaliere, which is a piece of jewellery, normally a pendant, which hangs from one’s neck. Lav mics are small, commonly omni-directional mics that are attached, using clips, tape or other forms of adhesive, to the subjects on camera. They are used a lot during interviews and news reports, where they can be displayed quite prominently, normally on the lapel of a jacket, the middle of a shirt, through one of the button holes, or on a dress, just above or to the left of the bust. These mics are great for getting crystal clear dialogue, as the mic is literally on the subject’s person, and because the mic is omni-directional the subject is able to move their head to some degree without degrading the audio quality. Lavalier mics do have their drawbacks though.

“Lavs do not sound as natural as boom mics. Lavs sound like lavs. These mics are devoid of perspective… Lavs are dialogue focused, since they are typically mounted on the actor’s chest. As a result, they sound sterile and unrealistic.” Rick Viers, 2012

If we were to only use lavalier mics, we would have to do a lot of post production work to add in perspective and room tone, or the actor’s dialogue would sound odd and out of place. We want to obtain the best sound we can on location, as that will save valuable time when come to post production, so ideally we would want to boom the entire film, though that isn’t always a possibility. Another issue is that we can’t mount lavs on actors where they can be seen easily, as Cognition is a dramatic film. We will therefore need to hide the mics, and when they are covered by fabric, the sounds they pick up are muffled slightly. We can take steps to remedy this by talking with the Director regarding costume choices for characters, as softer materials are more favourable to rougher ones, so this isn’t too much of an issue. We’ll have to be aware of contact noise, which occurs when clothing rubs up against the mic or its cable, making noise that appears on the recording, and also clothing movement, where two sections of clothing rub against each other and create noise. Lavs are excellent as a backup, so we will be using wireless lavalier mics on actors, in case boomed dialogue isn’t possible. In certain circumstances, it may be possible to combine lavalier’d and boomed dialogue in post, in order to get the best of both mic types. If we have the chance I’d like to try and use these mics, along with a boundary microphone if  available, as plant microphones in scenes that require them. This will let me meet one of my learning outcomes, gaining more knowledge and experience with location recording techniques.

Our chosen wireless lavalier microphone, the Sennheiser SK100.

Media loans has two kinds of wireless lavalier mics available, the Sony URX-P2, and the Sennheiser SK100. Based on prior experience with both microphones, I feel like the Sennheiser is the better choice here. It is slightly smaller, the batteries are easier to swap out, lowering downtime on set, and crucially, it provides better quality audio in my opinion. We may have been unlucky, but each time we used the URX-P2 mics, the quality was always worse compared to the SK100, and we encountered far more interference as well, which at one time got so bad we simply couldn’t use the mic.

In conclusion, we will be using a Sennheiser MKH416 shotgun mic and two Sennheiser SK100 wireless lavalier mics when shooting Cognition, along with a Sound Devices 633 Mixer Recorder, which I will be talking about in greater detail in the coming weeks.

References:
Viers, R. (2012) The Location Sound Bible. Studio City, CA: Michael Wiese Productions.