Microphone Polar Patterns Explained

Microphone Polar Patterns Explained
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Microphone Polar Patterns Explained

What features should we be looking out for when buying a microphone, and what benefit does it make to you as a musician or engineer to have a microphone with one, three or five pickup patterns? Which polar patterns do I need and how do we get the most out of them?

Here’s a little bit of tech. The way that we display a microphones directional sensitivity is with a polar diagram. If 0-degrees is at the top indicating the front of the mic and 180-degrees is directly behind the mic, then we can get a plot of the sensitivity across the microphones whole 360-degree field.

The term on or off-axis refers to how the mic is positioned to the sound source. If the mic is said to be ‘on-axis’, then the sweet spot of the mic is straight down the 0-degree direction on the polar pattern. If it is ‘off-axis’, then it is coming from the side or rear of the polar pattern. If a microphone is said to have a 'neutral or flat off-axis response', this is a good thing!

 

 

Cardioid

Almost all microphones feature a Cardioid pattern, which appears as an inverted heart shape response on a polar pattern graph. This is likely the pattern you would use most often. Mics with a cardioid response are most sensitive from the front with a good level of rejection from the rear, which is why most stage mics have a cardioid pick up pattern, this helps prevent feedback when you are cranking the monitors on stage.

Cardioid mics are not without their issues, a common problem being the ‘proximity effect’. This is when there is a bass lift in the tone when you get closer to the diagram or capsule. Often when recording we want to capture a neutral tone, so knowing about how to tackle the proximity effect can be useful knowledge.

 

Omni or Omnidirectional

A mic set to Omni is sensitive to sound coming from the full 360-degree field around it, and this is generated using two matching diaphragms positioned back-to-back in a single capsule, hence not all condenser microphones have an Omni setting. Single diaphragm mics normally only offer a cardioid pattern.

Omni mics don’t suffer from ‘proximity effects’, but they have their own unique quirks. Due to them being sensitive from all directions, other close sound sources will be picked up just as clearly as if they were on or off-axis, this includes any sonic reflections from hard sources. Therefore, if you’re in a ‘live-sounding' room stick to cardioid for your vocal recordings.

 

Figure-8

The figure 8 pattern, also known as bi-directional can be created one of two ways, by using a twin diaphragm condenser microphone or a ribbon mic. Figure 8 patterned mics boast strong sensitivity at the front and back with fantastic rejection at the sides which makes them an excellent choice for recording two vocalists at the same time.

A figure 8 mic is an essential tool when creating an MS or MID side microphone array, where two microphones are used to create a strong stereo image. The figure 8 microphone is duplicated in your DAW to create both an in-phase and out-of-phase version, these tracks are then panned hard left and right; A cardioid mic is then placed through the middle.

 

Also worth mentioning…

Two other microphone polar patterns worth noting are hypercardioid and subcardioid.

Hypercardioid is a more focused pattern, meaning that the off-axis side rejection is increased, but at the expense of more sensitivity at the rear of the microphone, you could consider it as figure 8 lite...

Subcardioid (or wide) polar pattern gives a much wider and broader range of front sensitivity. This is brilliant when you are recording several vocalists for backing vocals or tracking a physically larger instrument.

 

If you would like to know more about the wide range of different microphones that we offer, don’t hesitate to get in touch with our team at sales@studiospares.com or 02082089930.