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An Introduction to Equalization - A free download from Audio Masterclass

Equipping Your Home Recording Studio - A free download from Audio Masterclass

An Introduction to Compression: Basic Compression - A free download from Audio Masterclass

'Soundproofing' or 'sound isolation' - which is correct?

Comment of the week: Just how hard is it to 'get into the groove'?

Audio problems at the BBC - TV drama audiences can't understand what the actors are saying

Can curtains provide good soundproofing?

Q: How should I set the compressor in a live stage show?

Make an attention-getting lo-fi introduction for a track

Which DAW sounds best?

Jensen releases Jet Falcon 10"

Q: How do I place my mic on the hi-hat?

If you had no dangly thing at the back of your throat, how well could you sing?

How omnidirectional is your omnidirectional mic?

An omnidirectional microphone ought to be equally sensitive in all directions. But is it really?

It is a fact that real-world omnidirectional microphones are not equally sensitive in all directions.

But first, why would you buy an omnidirectional microphone anyway?

Has it ever crossed your mind that you really need a microphone that is equally sensitive in all directions?

I would imagine not. Mostly we use directional microphones because we want them to capture the sound source, and not other sounds from around the room.

And even if you did want to capture sounds from all around the room equally, the result would be a tremendous confusion.

You can of course use omnidirectional mics intentionally as ambience mics. But you will find that cardioids work just as well in that application (there are reasons why you would probably not choose figure-of-eights).

In fact, with cardioids you can point them away from the direct sound source and get a greater proportion of reverberation, which you can mix in with your close mics.

No, the reason why people sometimes choose an omnidirectional microphone is that omnis have great clarity. The polar pattern just happens to be omni - it's the clarity they want.

The reason for this is because omni mics are simple in design. Figure-of-eight mics are simple too. Cardioid, hypercardioid and multi-pattern mics are complex, so you don't expect the sound quality to be quite as natural.

The plain fact about so-called omnidirectional mics is that the polar pattern generally narrows at high frequencies. So you still do consciously have to point them at the sound source.

But this doesn't really make much difference in practice. If someone came out with a genuinely omnidirectional microphone, it wouldn't shatter the Earth; it would be nice, but wouldn't make all that much difference.

Isn't it nice when there's something you don't really have to worry about?

By David Mellor Thursday November 30, 2006