“Why do you need to get the boom closer, they’re wearing a lav?”
As a field mixer, this is one of the most common questions I am faced with by directors. There seems to be an understanding, particularly amongst low budget productions, that as long as talent is wearing lavalier microphone, then there is nothing to worry about. In this article I want to disband a few common beliefs about the use of lavalier microphones, and provide tips on how and when they should be used.
Tip #1 The sound from a boom mic will almost always sound better than a lavalier.
Boom microphones have a larger diaphragm than lavaliers, allowing audio to be recorded with fuller quality. In the hands of a skilled operator, the boom mic can also be moved up and down, position adjust during a take to help capture a natural and realistic recording of the dialogue. Lavaliers cannot be corrected or re-positioned during a take if there is a problem.
Tip #2 If you’re filming drama/short film/feature film, you want to have a clean boom track.
As mentioned, boom mics almost always sound better than lavalier microphones. If your project is more artistic in nature, or is aimed at festivals or wider distributions, you are going to want the highest quality of audio possible. Plan your shots to allow for this. This does not mean that lavalier mics shouldn’t be used. Sometimes post-production editors will use a blend of both boom and lavalier microphones to create a more well-rounded sound. Talk to your editor and ask if they are intending to do this.
Tip #3 Do you have the budget for lots of foley?
Boom mics have the benefit of recording character movement as well as dialogue. Lavalier microphones capture less of this room sound, and a little more clothing rustle. If you are working on a low budget project that does not have the money to pay a foley artist to reconstruct diegetic sound, a boom microphone will treat your more favourably than lav mics and provide a more realistic representation of the scene.
Tip #4 Be consistent with the microphones you use.
If the rest of your scene/scenes of your project have been filmed using a boom, a cut to lavs will be audible, or vice versa. The dialogue still works, but there will be a change in timbre. Maybe your general audience won’t hear the difference, but most professionals will. Try to be consistent with the source of the sound you use.
Tip #5 Boom mics can save time.
More often than not, on low budget productions I find I don’t have the possibility to see costumes before hand. The type of fabric and the design of clothes can have a tremendous impact on the reliability of lavalier mics. Certain materials just don’t work and you can waste a lot of time trying to make it e.g. polyester shirts are stiff and often rub on the cable no matter how much work you put in to keep them in place. Even if you do find a safe spot in troublesome clothing, there is always a strong chance of the lav slipping and you will need to keep returning to re-adjust it. This can lead to time being wasted and actors becoming frustrated. Boom microphones do not have this problem.
Tip #6 Large cast but can’t afford a boom operator?
The sound mixer is only one person. It is a tremendously difficult job to monitor multiple lavs and swing a boom pole. When monitoring lavaliers, I usually switch between different channels during a take to check that all is working well. If my hands are busy on a boompole, this I cannot do and my concentration is often so focused on the movement of the talent’s head/position of the camera that if there is a problem with the lav tracks there is a large possibility of it being missed. If there is a problem with the levels and I need to adjust, I also can’t do this because my hands are busy on the pole. In most cases I would really advise hiring a boom operator to ensure the best quality audio is achieved, but if you really cannot afford this try to make it easier for your sound recordist by keeping the cast small/not expecting a large cast to be mic’d and boomed simultaneously by one person. There are sound mixers out there who will do this without complaint, but this does not mean their result will be the highest quality.
So when can I rely on lavalier microphones?
So far, I have talked largely about the cons of using lav mics. 90% of the time when working, I will favour the boom and push to be as close as possible without breaking the frame. In these situations, lav mics are usually backup in case there is a problem with the boom track that truly cannot be solved. However lav mics are still useful and there are occasions on which they may even be considered preferable.
Establishing Shot
This shot is too wide to keep a boom in and even if the operator manages to get it above the frame, the boom will likely be too distant to capture anything useful. Sound is recorded from lavaliers, but will likely be dubbed over with dialogue from closer takes. For this reason it is always useful to run the entirety of dialogue on close-ups, even if you know that you won’t be using this shot for the whole scene.
Wide shot for artistic choice
All dialogue and action takes place in a wide where holding a boom would not be possible. An example of this would be films by director Roy Anderson. If you decide to go down this route, see if there is any possibility of hiding boom mics as plant mics in the scene (e.g. behind props). Make sure also that all clothing is approved by the sound recordist before hand to minimise the chance of clothing rustle.
Large group conversation
This situation occurs most often in documentary or ENG productions. I was once asked to film a discussion between 8 people sat around a table. The space was small, the camera angle wide and the discussion would last one hour. If I had used the boom I would have risked dropping the boom in frame between changes in speech, straining my back and arms by holding the boom for that length of time and potentially missing important conversation. Instead, I put lav’s on each of the participants and agreed with the producer that the microphones could be on the outside of the clothing. With the microphones on the outside, I could more safely position them to avoid clothing rustle, thereby avoiding the risk of having to interrupt mid-filming for adjustments.
Improvisation
Similar to the large group conversation, if actors are improvising there is a high risk that the boom operator might miss parts of lines. In these cases you want the talent to be mic’d to make sure you get full coverage of each take. A good example of this type of situation is the film Victoria (2015) directed by Sebastian Schipper.
The talent is difficult to reach
E.g. you are filming someone partaking in sport or an activity where it would be unrealistic to have a boom operator running alongside. This situation most often occurs again in ENG and documentary filming.
Poor acoustics
In rooms with a lot of reverb, boom microphones pick up more of room atmosphere than lavaliers. If you are considering in filming in such a room, be certain that you are aware the impact that the sound quality will have on your overall production and that you are happy with it. Always consult with your sound recordist before settling on a location.
High budget drama
As previously mentioned, audio editors may sometimes blend boom and lav tracks to created a well-rounded sound. This happens most frequently on high budget productions where a full sound team can be provided and much communication between departments happens in the pre-production stage (t.ex. with costume) to ensure that both boom and lav tracks can be as clean as possible.
No matter what type of production you are running, my final and most important piece of advice to you is to plan thoroughly and ask your crew what they need. Clear and effective communication is the solution to most problems.
Thank you for your time in reading my article and I hope that it has helped to shed some light on whether you should be using boom or lavaliere microphones, or both on your next production.
