While that might sound like a complete cop-out (and a pretty useless statement), it couldn’t be further away from the truth.
The fact of the matter is, it all depends on what you are recording and the sound you are going for.
An Introduction To How Microphones Work
In broad terms, all microphones work in a similar way.
The mic itself picks up sounds (or vibrations) caused by vocals or an instrument and changes them to an electric signal via a diaphragm within the microphone.
The diaphragm is designed to move back and forth and this is how the vibrations are recognized.
While there are many classifications of microphones, there are two main types of microphone we talk about in production – Condenser and Dynamic.
Let’s talk about these two first.
What Are Condenser Microphones?
Condenser microphones (such as the Neumann TLM102 or 103) are typically used for recording sounds with intricacy and detail, which is
why they are often used for vocal tracking. They are however quite fragile and need to be put away
after each session as any dust that finds its way onto the diaphragm can cause problems with the
mic further down the line.
A condenser will be ‘Phantom Powered’ which means it needs a small amount of current in order to work. You’ll usually find a button on your interface, preamp or console that says ‘+48v’ by it.
Switching this on will send the current to the microphone, but make sure to do this before you start
to gain stage or turn your faders up to avoid any nasty pops which could damage your monitors.
What Are Dynamic Microphones?
Dynamic microphones, on the other hand, do not require phantom power to work. They are not as
sensitive as condensers and so are often suitable powerful or aggressive vocals.
Dynamic mics are also often more durable than condenser mics which is why you’ll usually find a Shure SM58 dynamic mic on stage at gigs.
Not only are they able to cope with the loud sounds of a live band but they can usually handle rough treatment like being thrown into a bag or case at the end of a gig (although we’d never recommend throwing your mics!).
What Are Ribbon Microphones?
Ribbon microphones are actually types of dynamic microphones, however, are a lot more fragile due
to the way they are constructed.
The way a ribbon sounds could be loosely compared to a condenser mic, however, they do have quite different characteristics.
Unlike a condenser, a ribbon mic tends to sound smoother and darker. They are a great choice for getting a ‘warmer’ sound.
They are however quite fragile, despite belonging to the dynamic mic family, and switching on
phantom power in error can easily damage them.
What Are Shotgun Microphones?
Shotgun microphones, aside from having a really cool name, are great at recording a pinpointed
source of the sound.
They get their name from the fact that they need to be aimed directly at the sound source, much like
if you were firing a shotgun.
If you’ve ever seen a behind the scenes clip of a TV or film shoot, you’ll probably have seen a shotgun mic being pointed at the actors above the camera.
Because of its accuracy, the shotgun mic is great for situations such as this where you would want to reject any off-axis sound.
They wouldn’t be a great choice in a studio where you wanted to pick up the natural sound of the room.
What Are Pencil Microphones?
Pencil microphones are named this way due to their long thin sizes. You’ll often find these being
used for acoustic guitar or piano recording.
They have a small diaphragm and are suited to picking up higher frequency content.
Small Vs Large Diaphragm Microphones
Generally related to condensers, you’ll see various microphones described as ‘small’ or ‘large’
diaphragm. The diaphragm itself simply refers to the internal part of the mic that moves in order to
pick up sound.
A large-diaphragm will generally have a deeper response to low frequencies (due to the size of the diaphragm being bigger) but will also be more sensitive.
On the other hand, a small diaphragm mic will be more suited to higher frequency instruments such as cymbals. A small diaphragm will also have a smoother frequency response.
A large-diaphragm condenser tends to give out a bigger output than a small diaphragm, which means it’s signal to noise ratio is a lot bigger, making it great for recording quieter instruments.
Microphone Polar Patterns: Explained
When choosing a suitable microphone, a producer will consider the polar pattern of a microphone.
Essentially, changing the polar pattern will change the directional impact a microphone has on capturing sound.
Many microphones will allow you to switch between polar patterns, however, a cardioid is
often the ‘default’. A cardioid polar pattern means the microphone will pick up sound in a heart
shape (hence the name) around it's front and reject from the base.
A hypercardioid operates in a similar way to a cardioid mic. These types of microphone offer a greater amount of rejection from the sides, however they will pick up more sound from the rear of the mic.
A figure 8 (sometimes called a bidirectional) picks up sound in an ‘8’ shape around the mic. If you imagine two microphones pointing away from each other then it’s easy to picture how a figure of 8 works. Rejecting sound from the sides, a figure 8 is a great option for recording two vocalists at once.
You’ll often find you can select between polar patterns on your microphone, so try each one and see
what result you get.
Other Microphone Features
Aside from polar patterns, you may find a couple of other options on your microphone such as a High
Pass Filter and Pad option.
High Pass Filters (HPF)
A High Pass Filter cuts off some of the lower end response from the mic (allowing the highs to pass
through). The cut off usually lies around 50-80Hz but can often be 100HZ or above.
You will probably find you won’t hear a huge difference to your vocals or instrument with the HPF on
or off, however, it will eliminate any unwanted hum or rumblings that may be being picked up in the room that would cause a muddier sound.
A pad will simply reduce the output level of the microphone by a certain amount of dB. If you are
recording a drum kit, you will commonly find you need to use this switch due to the extremely loud volume of the instrument.
When gain staging, you’ll know whether to switch the pad by your signal level. If the signal is
extremely hot with only a slight increase in gain, it’s best to reduce this at the source via the mic pad
(although you will often find a pad option on your console or interface).
You’ll also need to consider whether you’ll need to purchase a pop shield (or pop filter). A pop filter
is the circular shaped mesh you’ll often see placed between a singer and their microphone in the studio which eliminates any nasty popping or wind noises being picked up by the mic.