The main thing which differentiates microphones is their polar pattern. Microphone patterns refer to how much sound they’ll pick up relative to which way they’re facing. Different polar patterns are useful for recording different things, so let’s cover the various microphone patterns, how they work, and what to use them to record.
Polar Pattern Guide
Unidirectional microphones refer to those which are designed to pick up signal from a source positioned directly in front of them. There are a few different types of microphones which fall into this category. These include:
The most ubiquitous unidirectional type of microphone is the cardioid polar pattern microphone. It primarily captures the sound of what’s directly in front of it, rejecting the sides and rear. This makes it relatively effective at reducing unwanted noise while recording.
The spread in front of it is also wide enough (nearly 180 degrees) that if the source moves slightly, there’s not a big dropoff in signal.
A cardioid microphone is ideal for recording most single instruments and vocals.
Super cardioid microphones have a more narrow window of response. This means a super cardioid picks up even less of the sides than a plain cardioid with a bit of rear response.
While it’s more effective at cutting out unwanted noise, you need to be more careful about not moving the source during recording. A source needs to remain still and directly in front of a super cardioid to get the best results.
The super cardioid pattern also reduces feedback at high gain by rejecting anything which it’s not directly facing. This makes it useful for live sound when feedback is a common problem.
Going one step further, you also have the hyper cardioid pattern microphone. This is even more narrow, making it even more effective at rejecting unwanted sound, but making it even more important that the source not move during recording.
In contrast to unidirectional, cardioid microphones which only face one direction, omnidirectional microphones pick up 360 degrees.
This makes them ideal for capturing a raw live sound in recording an entire room, a group of singers positioned in a circle around the microphone, or any instance where there’s too many sources to line up on one or two sides.
It’s also nice for recording an entire drum kit or piano with a single microphone when you have sound information coming from a larger area left to right without missing anything.
Because there’s no rejection of any kind, omnidirectional microphones pick up everything. This makes treating the room or removing as much unwanted room noise ahead of time paramount when recording with an omni.
Bidirectional/Figure 8 Pattern Microphones
Lastly, we have bidirectional microphones. Also known as figure 8 due to their pattern, these microphones pick up what’s directly in front of and behind them equally.
This makes them ideal for recording two singers on either side, podcasters or any speech with two sources on either side, or specific recording techniques like mid side mic technique.
Bidirectional microphones rejects everything to the sides, so they pick up less noise. Still, it’s important to be mindful of sources of room noise when recording with a figure 8 to get the best results.
- There are a number of different polar patterns with microphones, meaning which direction and width they record.
- Unidirectional microphones like the cardioid pattern pick up what they’re facing, rejecting most of the sides and everything behind them.
- Cardioid microphones are ideal for recording any single source, whether it be a vocal, acoustic guitar, etc.
- There are narrower cardioid pattern microphones like the super or hyper cardioid. These reduce more side noise but your source needs to be directly in front of the microphone for a good result.
- Omnidirectional microphones pick up 360 degrees, making them great for recording an entire room, a circle of singers, a drum kit, or a piano with a single microphone.
- Omni microphones have zero sound rejection, so they come with a lot of noise. Room and noise treating is especially important with them.
- Bidirectional or figure 8 microphones capture what’s directly in front of and behind them equally. Rejecting the sides entirely, these microphones are ideal for two singers or speakers on either side or particular recording techniques like mid side.