Microphone Polar Patterns

Introduction to Music Production Week 1

Let’s begin Hello class,

My name is Arjun Nair, from Mumbai, India. I’m going to be attempting to take you through a specific aspect of Microphones which interest me, viz. Polar Patterns

Here’s what we’re going to try and cover in this lesson:

•  What do we mean by Polar Patterns for a Microphone?

•  What are the different types of patterns that exist? Types, Uses and Examples.

•  Basics to keep in mind while choosing between Polar patterns for your Microphone

This lesson will be more useful if you’ve covered Microphone as a Transducer, and Microphone types available at the following link (https://class.coursera.org/musicproduction-001/lecture/19)

What are polar patterns? �  The polar pattern of a microphone refers how well

it “hears” sound from different directions.

�  It refers to what areas of the Microphone are sensitive to the sound pressure directed at it well and what areas reject it.

�  Every Microphone can be designed with any type of pattern

�  These polar patterns can be represented diagrammatically

What are the different types of Polar Patterns?

We will look at three main patterns in their following aspects: •  What (How the Microphone will hear the sound) •  What are the possible uses/advantages of such

a Polar Pattern in a Microphone? •  An example of a microphone designed with such

a polar pattern

What are the different types of Polar Patterns?

Three broad Polar patterns we will look at: •  Omnidirectional •  Bi – Directional •  Unidirectional

•  Cardioid, SuperCardiod, HyperCardiod

Omnidirectional What :

•  With this Polar pattern, the Microphone picks up sound equally well from all directions. The Mic picks up everything within the given space.

Uses:

�  When the Microphone needs to pick up ambient sound

•  When the Microphone is used in an environment where sound sources are moving (since it’s not practical to have a mic move with these sound sources ;) )

Omnidirectional

Example:

Shure VP64A

Bi – Directional

What:

•  As the name suggests, with this Polar pattern, the Microphone picks up sound equally best in two directions -- in front of and behind the mic -- and rejects sounds to the sides

•  Also known as ‘Figure 8’ pattern

Bi – Directional

Uses:

•  This is useful in recording Dual sources simultaneously

•  Creatively used in recordings also because of the areas that Do NOT pick up sound.

Bi – Directional

Example:

•  Ribbon Microphones •  Blue Microphones -

Woodpecker Active Ribbon Microphone

Unidirectional

Cardiod What:

�  With this Polar pattern, the Microphone picks up sound best in front of the mic and Partly rejects sounds approaching the sides or rear of the mic. Cardiod mics reject sound best toward the rear.

�  The pattern resembles the shape of a human heart, and hence the name

Cardiod

Example:

•  Shure SM 58

SuperCardiod

What:

�  With this Polar pattern, the Microphone picks up sound best in front of the mic. It partly rejects sounds approaching the sides or rear of the mic.

�  It has a "Tighter" or more narrow pickup than cardioid.

SuperCardiod

Example: CAD 25A Dynamic Supercardioid Microphone

HyperCardiod

What:

�  With this Polar pattern again, the Microphone picks up sound best in front of the mic. It partially rejects sounds approaching the sides or rear of the mic.

�  It has a "Tighter" or more narrow pickup than SuperCardioid.

HyperCardiod

Example: Audix OM6 Broad Hypercardioid Microphone

Differentiation

Cardiod SuperCardiod Hypercardiod

•  Picks up maximum towards the front

•  Offers maximum rejection (null) at the rear of the microphone.

•  Narrower pickup than Cardiod

•  Also has some rear pickup

•  Narrower pickup than SuperCardiod

•  Also has more rear pickup than SuperCardiod

•  Primarily differentiated based on not just the pick up, but what it rejects

Uses for UniDirectional •  Cardiod

•  Used for live sound, for vocals for instance, since it picks up concentrated sound and eliminates ambient sound like the stage monitors.

�  Supercardioid

�  Good for stage-floor miking

�  More isolation than a cardioid

�  Less reverb pickup than a cardioid

�  Hypercardioid

�  Maximum side rejection in a unidirectional mic

�  Maximum isolation--maximum rejection of reverberation, leakage, feedback, and background noise

Concluding Tips A few things to keep in Mind while choosing between polar patterns: •  Most microphones boost the bass when used up close. That adds a

warm, full tone quality. Microphones with an omnidirectional polar pattern do not have proximity effect.

•  Choose an omni if you want the most natural sound and don't mind about sound being picked up from all around, like recording crowd reactions in a stadium.

•  Choose any directional mic if you want to reject sounds from certain directions, or if you want a bass boost for a nearby source, such as a vocalist. A cardioid will be a good all-round choice.

•  Choose a Supercardioid mic if you want a tighter focus than a SuperCardioid

•  Choose a hypercardioid mic if you want a tighter focus than a SuperCardioid.

•  Choose a figure-of-eight if you want to reject sound sources coming from the sides, or if you want to use a two mics for stereo.