Whether you are onstage or in the studio, a little knowledge of polar patterns can go a long way to enhancing your performance –says Chris Kennedy.
1. Getting Started: What is a polar pattern?
A microphone’s polar pattern refers to how well a microphone picks up sound from different directions. In a live setting, it is important to make sure you are using the right type of microphone to minimise feedback and to know where to position your monitors correctly for the polar pattern you are using. In the studio, you can use the different pickup characteristics to alter things such as the amount of room ambience in your recordings, or the amount of proximity effect. Some studio microphones have fixed patterns and some have variable patterns to give you a wider range of options.
2. Cardioid: Only picks up from your side of the mic
This is the most common polar pattern singers will come across. It is often described as having a heart-shaped pattern and is probably the most used one in the studio for recording vocals. The sensitivity of a cardioid microphone reduces the further you move from the front of the microphone (to the sides) and it has essentially no pickup on the reverse side. This is particular useful in a live situation where you don’t want to pick up the sound of the audience or from your monitors (monitors should be placed directly facing you at 180 degrees if using a cardioid mic). In the studio the polar pattern is useful for minimising the amount of room ambience and reflections picked up by the microphone – which is useful if you are recording in a less than ideal environment – or help to block our other musicians performing around you in the room.
3. Hyper-Cardioid / Super-Cardioid: Improved side rejection
This polar pattern is becoming increasingly popular in live microphones such as the Shure Beta 58 or the TC-Helicon MP75. It features a much tighter pattern than a standard cardioid microphone, making it even better at blocking out the rest of the band on stage and just picking up the vocals. One downside to these however is they also have some pickup directly at the rear of the microphone. This means you should not place you monitor speaker directly in front of you (generally around 120 and/or 240 degrees is typically best) or you will suffer feedback. Super-cardioid microphones typically used in the studio when you need maximum isolation from other sounds, such as on toms on a drum kit, and are rarely used on vocals.
4. Omnidirectional: Picks up everything around you
An omnidirectional microphone picks up equally in all directions. As such they are rarely used in a live setting due to feedback issues; however they can be a useful tool in the studio, especially if you want to get more of the sound of the room in your recording. Another useful feature of omnidirectional microphones is that they do not suffer the same proximity bass boost you get with a cardioid microphone, meaning the sound will not change much and sound natural if a singer moves around a lot while performing. You will also often find these microphones used for recording acts such as traditional folk groups where all the singers/musicians gather around one microphone to perform as a whole and balance there levels as they perform.
5. Figure-8: Common for ribbon mics
As the name suggests, figure 8 polar patters pick up in a shape that closely resembles the shape of the number 8. They are used typically more in the studio than in a live setting and are the typical of characteristic of the majority of ribbon microphones. They pickup sound equally from the front and the rear and nothing form the sides. As such, if you are using a ribbon microphone to record vocals with a figure-8 pattern, you would need to watch out for room reflections from directly in front of you hitting the microphone causing phase issues. One great use for figure-8 mics is to record two singers performing around a singer microphone as you can have one at the front of the mic and one at the rear, while also reducing room ambience from the sides.