Why it's Important to Pay Attention to a
Microphone's Polar Pattern
A microphone's polar pattern is a way of showing the 'directional sensitivity' of the microphone. Some microphones have fixed patterns, whilst others are able to switch between many different patterns.
It can also be described as the 'pick-up pattern' of the microphone, and the pattern shows how well a mic responds to a sound depending on the angle that the sound arrives from. The best angle of response is known as the on-axis response, whilst other angles are known as off-axis.
There are a few different types of microphone polar pattern found in today's mics, each of which I'll go through here.
- can pick up sound from all directions (although you may lose a bit directly behind the mic, especially higher frequencies)
- captures natural, un-colored sound
- no proximity effect (this is the effect where lower frequencies increase as the sound source gets closer to the microphone)
- picks up the most room sound out of all the different patterns, which is why you shouldn't use these in poor-sounding rooms
- if you'd like to capture a room's natural reverb during recording, use this pattern
- can handle higher sound pressure levels
- a directional microphone pattern
- these have a good rejection of sound from directly behind the mic (up to -25 dB)
- some sound rejection from the sides of the mic
- great response from a wide angle of sounds in front of the mic
- features proximity effect
- less responsive to room sounds
- useful for close, intimate sounds as well as brash, up-front sounds
- more directional response at the front of the mic, but poorer rejection from directly behind the mic (compared to a cardioid mic)
- the tighter the pickup angle is at the front of the mic, the more sound is picked up from directly behind the mic and the more rejection there is at the sides of the mic
- in the studio during recording, if you have unwanted sound coming from behind the mic, it's better to use a cardioid
- if unwanted sound is coming from behind and to the sides, use a supercardioid or a hypercardioid for better rejection of these sounds
- usually found in condenser or ribbon microphones
- figure-of-eight pickup pattern
- features the proximity effect
- usually condenser mic models
- very tight pickup pattern at the front of the mic
- a specialist shotgun mic is commonly used in film and TV, as well as sports stadia
- sound not covered by the pick-up pattern is very heavily colored
The arrangement of the diaphragm capsule inside a microphone has a large part to play in the directional response.
The types of microphone shown below usually have large diaphragms with side-address capsules (also known as side-firing). This means that sound can hit both the front and the back of the capsule:
The types shown below usually have small diaphragms and have an axial arrangement (end-firing), where the back of the diaphragm can't be reached:
Learning about the polar pattern features of microphones can help you in choosing the right mic to use in different recording situations. To start with I recommend getting a cardioid mic. But many microphones can swap between different patterns, so keep an eye out for one of these if you'd like to have some flexibility in your home studio.