Friday, 25 May 2012

Why cupping a mic looks cool but thats about it..

Cupping is for musical dicks
You see it on hundreds of music videos (mostly in Hip Hop) and as a result you see it occuring more and more on live stages of all genres. The lead vocalist with their hand wrapped around the base of the microphone ball. Wow they look so cool!!.
But mic cupping, is bad for you and here is why...

Despite what most people think, there are two sides to a microphone. Most think that it just the front part where you stick your mouth or point at the instrument that is the important part. However the back of the mic plays just as much a role in both the way the mic sounds and also how the mic responds to its environment.

Most vocal mics have what is called a 'cardoid' pattern, that means they mostly respond to sound from the front of the mic and 'reject' sound from the back of the mic. Thats why you can turn a mic up loud and point the bottom of it straight into a speaker and you won't get feedback. However flip it around and point the mic directly at the speaker and you will get a load of feedback.

When you cup a mic, you change the response pattern of the mic from cardoid (only from the front) to Omni-directional.
That means the mic picks up sound relatively equally from all directions, not just where you point it. The immediate thing you will notice is that a cupped mic feeds back much more easily than an open mic.

You can try this for yourself, just turn on a mic and turn it up fairly loud, then cup it by putting your whole hand around the ball of the mic and watch the feedback go crazy.

Cupping is also going to destroy the sound because the microphone is going to pickup sound from everything else around the stage as well as the vocalist this is what makes it sound 'muffled'. Basically, if you like the sound of a cupped mic, you may as well just ask your sound engineer to turn up the 'Shit' knob on the mixing desk.

A cupped mic will sound quieter than an un-cupped mic but of course you will not be able to turn it up because it will feedback at between 1/2 to 3/4 the volume of an un-cupped mic (depends on the mic model).
One other thing to watch out for is tape or anything else that might get stuck to a mic at some point, if you tape up a broken mic, it will also cause the same effect. Sometimes you can use this to your advantage, for example if you are mic'ing up a percussion instrument where there is sound coming from all around, I will sometimes use an SM57 with tape over the bottom grill to get a more full sound from inside a drum.

You can also use this phenomenon as a good visual indicator of how a mic's response pattern will be. Generally microphones with big rear grills will be highly directional, while microphones with no or a very tiny rear grill will be more omni-directional. Watch out because this is counter intuitive to what you would expect to happen.

So there you go, next time you see some rockstar prancing around the stage with their hands wrapped around the ball of the mic, tell them why it might look cool but is actually seriously uncool for their sound.

1 comment:

  1. i always held the mic like that to stop smashing my teeth.. rapping and jumping round on stage you can chip that shit easy as.. maybe thats why?
    it always felt better, louder (with corded mics), sounded better (to me) and cupping it on the monitor side stopped feedback happening..
    i dunno, good write-up and theory, but i reckon in practice it is what it is..
    cordless mics i never cupped though.