Polar patterns are an essential piece of information when selecting microphones for pretty much any situation. Be it live or studio, high or low SPL (Sound Pressure Level) your microphone’s polar pattern will determine which microphone you use and how you use it.
So what are they exactly?
A polar pattern is the three-dimensional area of responsiveness that is present in every microphone. It displays the area in which your microphone will most effectively pickup audio above a certain volume. This pattern can vary dependent on frequency and even the volume of that frequency.
Also not all microphones are limited to one pickup pattern however. Microphones such as the AKG C414XLS and C-314 have intelligent capsules that can produce multiple pickup patterns. This obviously expands the versatility of the microphones and gives you a few more options when in the studio. However when using microphones with one pickup pattern the following aims to categorise the various types of pickups patterns available on the market and more importantly give real world examples of how they can be used.
This is arguably the most common of all polar pickup patterns. It’s designed to pick up audio coming from directly in front of the microphone whilst reducing audio present at the rear. This obviously makes it favourable for live situations as it reduces audio arriving from the rear of the mic such as other musicians on stage, monitors and FOH (Front Of House).
With the latter two it also helps reduce feedback. It’s also useful for recording situations where you want to capture just the source as opposed to the room around it. Lastly when recording in high SPL situations, drum kits for example, cardioid offers the ability to capture specific sound sources whilst reducing the amount of background noise.
Super Cardioid, whilst similar to normal cardioid, is slightly more focused. This means it has an even tighter pickup pattern and rejects even more audio from the rear sides of the mic.
So why would you use cardioid over super cardioid?
The main reason is the super cardioid’s narrow field means a performer has to remain pretty still whilst recording. In live situations this is not always possible and singers in particular may consistently move out of the microphones pickup pattern. On the flip side of this they are better at rejecting feedback, so for situations where the performer remains still a super cardioid may be preferable. It’s worth taking into account the small area at the back of the mic as it’s prone to pick up on stage monitors. In a studio environment the very narrow super cardioid pickup pattern is great for capturing a single instrument or isolating a singer’s voice from any accompanying instruments.
Whilst in the same cardioid family the hyper goes one step further than the super. It presents an incredibly narrow and fixed field in which to record audio. When using hyper cardioid in live situations it’s imperative that the audio source remains fixed. Even veering slightly off axis can result in a wishy washy sound.
Also the extra sensitivity at the rear of the microphone can make it troublesome when placing stage monitors. Hyper cardioid can be used very effectively in microphones such as lectern microphones where a speaker is typically in one spot. For recording purposes many “pencil” mics will utilize a hyper cardioid for specific and directional audio capture.
As the name would suggest this pickup pattern is used to capture sound from all directions of the microphone. These patterns are perfect for recording very natural sounding sources as not only will they pick up the audio source but the room and other reflections as well. They are also useful for recording wide sound sources such an entire orchestra or choir.
Many lavalier mics also incorporate an omni directional pattern as it does not matter where the speaker moves their head the microphone will still capture the sound. Where caution must be utilized with omni directional mics is in live situations as they will pick up everything that happens on stage, wanted or unwanted and are prone to feedback. Also when recording in an acoustically untreated room the omni directional pattern will pick up anything that may adversely affect your sound.
Another pattern where the name is a giveaway, the figure 8 pickup or bidirectional as it also called picks up sound on either side of the microphone whilst rejecting sound along the 180 degree line. It is especially useful in studio situations when recording duets, one artist either side of the microphone performing at the same time. Also, as it covers such a wider area it can used as overheads for drum kits and orchestral groups. Just be careful about its placement as it will not pick up anything along the 180 degree axis. It’s rare to use a figure 8 mic in live situations, given the wide pickup nature of pattern unless you are in a particularly controlled environment it’s not recommended to use a figure 8 live.