Boom Microphone
A boom mic setup typically consists of a microphone mounted on a boom pole, equipped with a shock mount to prevent handling noise. It’s also often covered with a windscreen to reduce noise interference. Boom mics are the go-to audio solution in scenarios where lavalier mics could disrupt a scene’s authenticity, such as an interview or film.
The science behind boom mics lies in their ability to focus on a sound source from a distance, making them perfect for film sets where the mic needs to be invisible and not intrude on the scene. The microphones used are usually shotgun mics, known for their directional pickup patterns that can handle capturing sound from a distance. But this isn’t always the case. Boom mics are typically equipped with microphones that have hypercardioid or lobar pickup patterns.
Pickup patterns: Hypercardioid vs. lobar
Hypercardioid mics have a tight pickup pattern that is focused directly in front of the microphone and a small lobe of sensitivity to the rear. They’re generally best suited for indoor environments, especially ones with low ceilings and untreated walls that are prone to echoes and sound reflections. Stationary setups like interviews and dialogue recordings would benefit most from the use of a hypercardioid microphone.
Illustration of different microphone pickup patterns
Lobar pickup patterns are found in shotgun microphones, which are highly directional. These mics are designed to record audio at longer distances due to their interference tube design. This design means they don’t reject reverberations and reflections as well as hypercardioid mics, so they’re best to use in outdoor environments. Also, boom mic operators can take advantage of the mic’s increased directionality in an outdoor setting, allowing them to stand further away from a subject while still capturing clear audio.