Know the perils and opportunities of the three main pick-up patterns for mics. Sound engineer Wes Maebe makes it user-friendly.
There are 3 main patterns in which a microphone will “look” at a sound source.
By spending just a few minutes with this article, you’ll understand why certain choices for mics are being made and you will be in a better position to control your own sound.
The Omni Directional Mic
An Omni directional mic will pick up sound from all around; it will sound very open.
The Cardioid Mic
The Cardioid (from the ancient Greek, καρδιον,heart shaped), picks up sound in front of the mic, a fair amount from the sides, but has a “null point” at the back—this is generally the mic you’ll have for vocals.
The Bi-Directional Mic
This mic will pick up sound from the front and the back and reject sound from both sides.
Pick-up Perils and Opportunities
You have to be careful with the Omni-directional mics; if you happen to record in a very lively room, this sort of mic will pick up a lot of natural reverb or room ambiance.
The Cardioid has the benefit of rejecting sound from the back. This becomes a major asset when you move outside of the studio environment into live performance.
Remember that your stage monitors are blasting sound into the back of your microphone—because of the cardioid pattern, most of that monitor sound will be rejected (that’s good!).
Never cup a Cardioid microphone at the grill (like some Hip Hop artists tend to do); this turns the Cardioid into an Omni-directional microphone causing it to pick up sound from all around, i.e. monitor wedges, guitar and bass amps etc. This will inevitably lead to feedback!
If you have two monitors on stage, one on either side of you, there may be a better solution for you than the standard cardioid pick up pattern (which picks up very much in front of the mic, a fair amount from the sides, but has a null point at the back).
The Hyper-cardioid mic will behave just like the cardioid but it will reject sound from the sides at a 45° angle and pick up a tiny bit from the back, making it more open sounding and a favorite for backing vocals.
The Figure of 8 (or bi-directional) mic is a big favorite in voice-over situations. Because it picks up from both ends, you can have two voice artists on the same microphone, facing each other.
The same goes for vocal overdubs in the studio: if you’re recording vocals and an acoustic guitar and you want to capture your performance in one go with one mic, you can use the figure of 8 with the front of the mic pointing towards your mouth and the back of it downwards towards the guitar.
Your Next Step
Unlike finding your particular favourite microphone that works best with your voice, you can’t really find your polar pattern.
The polar pattern will in general be dictated by the situation you’re in, the acoustical environment, the sort of sound you want to achieve for a particular performance.
A live performance will pretty much always force you towards a cardioid or a hyper-cardioid microphone, just because you have to deal with stage monitors, front Of House P.A. spill, blasting guitar, bass and keyboard amps and a, by definition, loud drummer.
In a studio set up, the world is your oyster.
If you’re recording live in the room with the band, a cardioid will most likely be the answer.
Sometimes you can set up in the control room and do your guide vocals there. Engineers have plenty of tricks up their sleeves to reduce the spill from the near-field monitors, like putting them out of phase or setting you up with a reflection filter like the SE one.
When we put speakers out of phase, it basically means that when one speaker is pushing the sound out (positive phase), the other one pulls it back (negative phase) and they then cancel each other out.
The SE Reflection filter acts like a little portable vocal booth (see fig. beside); you can be in a purpose built vocal booth, so again, depending on the sound required you can go from cardioid all the way to omni.
There are mics out there that will do a lot of things, others are only good for certain jobs, so it’s down to you as a performer, with the guidance of your engineer and producer to experiment and find the right tool for the job at hand.
Armed with this knowledge, don’t be afraid to break the rules.
Wes Maebe directs his own mastering room in West London and has worked as FOH, studio/location recording, mix or mastering engineer for numerous clients including: Sting, Chaka Khan, Glen Matlock, Yusuf Islam, Alexandra Burke, Melanie C, Deborah Bonham, The Kooks, New Model Army, Elliott Randall, Hayley Westenra, Ann Peebles, Fairport Convention, Stiff Little Fingers, Specimen, Mo Foster, Exit 10 and The Zimmers!See Wes’ site.