Boom Mic VS Lav Mic

We have all heard that the boom mic sounds better than Lav mics and sometimes we don't want to ask the Soundie why we think that or sometimes we hear a lav mic and think wow that sounds way clearer and punchier why don't we always just use lav mics. 

Firstly, I want to start off by saying that there is never one thing that fits all systems for microphones. Many microphones have different use cases and excel in one way over others and there can be a lot of crossovers of use. 

Secondly this is all under the blanket of my experience working in sound. 

Ok with that out of the way let's start with the microphones themselves. 

A mic is usually a capsule surrounded in some kind of casing. Inside the capsule there is a membrane that fluctuates with the vibrations in the air and in the handling which creates a current that the recording device interprets as an audio signal. 

So if that is all it is, why are there different shapes sizes types of capsules? 

Each capsule will have pros and cons as a pretty clear example: a shotgun mic (a mic with an interference tube) has a narrow pickup pattern so can be a little further away from the audio source but will often struggle more in indoor or reflective environments. 

A mic with no interference tube will need to be a lot closer to the audio source but in a reflective space will sound a lot more natural and is often used indoors. 

An omnidirectional mic (the most common type being a Lav Mic) will hear an audio signal from all directions but often requires to be quite close to the source to provide a clean sound.

There are other mics out there but for this post these are the most important types. 

So, for the keen reader we can already see the difference between a lav mic and a boom but I will break it down into a few other points as well.

Story 

So, this would probably be the most important part for most readers to consider. As I am a nerd, I love all the details, but this element has the greatest effect on the final product. 

A lav microphone in a perfect placement with little to none clothing noise suffers from a proximity effect that doesn't tell the whole story of the piece.

When I walk into a room without even thinking about it, I am already getting a sense of where I am and what is around me and all these elements combine to tell a story of the moment I am in. 

Now stay with me here, let's say I walked into a corner store every sound I make including the door, steps, voice etr is bouncing off the walls and around the room in all directions, sometimes it's being absorbed into objects sometimes it bounces harder and all this tells me about where I am and what is around me and without that I am losing a layer of information that I believe takes away from a project.

Performance 

I want an actor to be able to perform without any inhibitions of movement and costume because I know that those are also layers that support the visual aspects of storytelling and often there is a compromise in audio fidelity or a compromise in costume in the form of fabrics, design and accessories that can thrash a lav mic. 

The movement on the other hand is also more restrictive for a radio mic. If an actor turns their head away we lose some of that performance, if the movement is to intense we can lose a lav to clothing noise, if they need to curl up or touch their chest at all then the radio mic is affected also it can be pretty uncomfortable at times there have been actors I have worked with that really don't like wearing radio mics.

Technician 

This part should hopefully be pretty simple and is it that an actor is not a sound technician and so doesn't need to and often doesn't have the know-how to use a lav mic in an appropriate way to ensure a well captured performance.

Hardware 

Lastly is the tech itself is smaller, though great for hiding microphones on clothes but it also will struggle more to get the source in its more complete form (that being said modern lav mics are getting really really close). 

We also have to factor in the mostly wireless transmission to the receiver which in itself has size and limitations in how reliably it can send a signal.

All of these things and more is why soundies love their boom microphones and often have a few in their kits. In the end though there are times when the lav mics really are the best tool for the job, but not often will they actually replace a well operated boom mic.

At least in my opinion!