Microphone Polar Patterns Explained
Introduction
It’s important to know polar patterns to get the perfect recording out of your microphone. The polar pattern is an important specification of a microphone that tells us the directional sensitivity of the microphone.
Right here you will learn every little thing you need to call yourself a pro. If you don’t work in the audio field, then the term could also be completely unfamiliar to you. Having a working knowledge of polar patterns, often known as pickup patterns, is essential when it comes to choosing the perfect microphone or microphones to make use of for a specific project. We’ll break down what a polar pattern is and explain the several types of patterns.
What are polar patterns/pickup patterns?
A polar pattern defines how much the signal can be picked up by the microphone from completely different directions. Although it might sound a bit complicated, a polar pattern simply describes a microphone’s inherent directionality.
By choosing the best pattern, you possibly can avoid unwanted sound sources to bleed into your signal, adjust the mix between dry and room sound, change the frequency response, and influence the proximity effect. A polar pattern is a space around a microphone where it picks up sound or is probably the most sensitive to sound.
These patterns may be visualized in a three-dimensional space. Totally different microphones have totally different polar patterns, and these patterns play a role in figuring out their greatest uses. Listed below are the 5 most typical polar patterns and their generic polar pattern graphs:
1. Directional/Cardioid
The cardioid polar pattern is the most common of the directional polar patterns – that is the one featured in the example above. So-named as a result of the response resembling a heart shape, it is widely used when there’s a need to concentrate on one sound source, simultaneously reducing pick-up from the sides and rear.
A cardioid mic is lots better at excluding background noise and room reflection than an Omni mic. Its commonest use is actually in music production and live sound reinforcement. However, filmmakers will encounter cardioid mics too, especially in stereo microphones.
2. Omnidirectional
Omnidirectional microphones have an equal response in any respect angle. Its coverage or pickup angle is a full 360 degrees, which comes with numerous distinct advantages or disadvantages depending on your application.
On the positive side, omnidirectional mics have a really pure and open sound that’s excellent for capturing natural sounds, such as an acoustic guitar. Alternatively, Omni mics pick up extra room ambiance, which may be desirable as long as you’ve great-sounding room acoustics.
In any case, the stability of direct and ambient sound may be controlled by various distances of the microphone from the instrument.
3. Bidirectional
Bidirectional microphones have a full response at both zero degrees (front) and at 180 degrees (back). They’re the least sensitive on the sides. This mic can be utilized to your benefit when choosing two sound sources such as two vocalists facing one another; however, most often, it is usually just to make use of one side.
The bidirectional polar pattern is often known as the figure-8 polar pattern as a result of the shape of the pickup area forming the outline of a figure-8. A bidirectional microphone records audio directly in front of and directly behind the capsule without getting any sound from the sides.
4. Hypercardioid
A hypercardioid pickup pattern is a directional pickup pattern that’s nice for isolating audio. While you may discover some lav mics with hypercardioid pickup patterns, you’ll usually only see this pickup pattern in shotgun mics.
Whereas each brand is completely different, the biggest difference between a hypercardioid mic and a supercardioid mic is how much of the rear and side noise is picked up. Hypercardioid mics are usually used for instrument recording.
5. Supercardioid
Supercardioid mics are the most popular kind of microphones for indie filmmakers as a result they give users the ability to isolate audio while still permitting a slight margin of error. Supercardioid pickup patterns are sometimes only found in shotgun mics which are used on boom poles or mounted to the top of a camera.
It must be noted that a supercardioid pickup pattern does pick up some audio from behind the microphone. So when you mount a supercardioid mic to your camera, you’ll have to keep your operating noise to a minimum.
Best Polar Pattern For Podcasting
When recording a podcast or other home studio content material, be sure to take the time to think about your studio as well as your content. For a lot of typical solo podcasts, a unidirectional pickup pattern will usually provide one of the best outcomes. Nevertheless, creative and unique podcasts could benefit from another kind of pickup pattern.
General, your microphone’s pickup pattern is a necessary part of your podcast. If you believe that you’ll make use of more than one directional pattern frequently, consider investing in a microphone that permits you to switch patterns. Although utilizing two unidirectional cardioid microphones, one for the host and one other for the guest would likely capture higher quality audio for each topic.
This way, you won’t need to worry about the audio system’s voices coming from completely different angles. Although now you have got two completely different audio sources you’ll need to deal with in post.
Why Do Microphones Have Different Pickup Patterns?
Our ears can do lots of things: We can simply hear what’s happening, or we are able to listen very closely. And sometimes we simply don’t need to hear about it. Microphones can do comparable things!
Let’s say you’re at a celebration, and there’s music playing and other people speaking. You enter the room, taking in the entire scene. You listen to the music playing in the background while everyone’s speaking, you may even secretly overhear a conversation where your name got mentioned while you’re saying hello to a friend.
It’s fairly amazing what we can do with only one set of ears! But then again, we now have a strong signal processor between our ears! Simply put, microphones come with totally different pickup patterns for the lack of a brain.
Using Microphone Polar Patterns Effectively
How does this very basic overview of microphone patterns and their characteristics help us when it comes to really make our recordings? Returning to our old good friend the cardioid, we now know that we now have to make allowances for an inaccurate off-axis frequency response and, if used actually close to a sound source, for proximity bass boost.
The directional qualities help keep instruments separate in the recording and also help reduce the quantity of reflected sound reaching the microphone, however, you possibly can make sure that any spill or reflected sound that does reach the rear and sides of the microphone will likely be significantly colored in comparison with an Omni mic utilized in the identical situation.
An Omni will, after all, pick up extra of the room sound, however, it’ll pick it up with much less coloration than a cardioid. Utilizing effective absorbers will significantly improve the standard of recordings made utilizing a cardioid-pattern microphone in an extremely reflective space, but few cardioid microphones sound as pure as a great Omni model, simply because of the best way the acoustic labyrinth behind the diaphragm affects the purity of the sound.
What is a Lavalier Microphone?
Now that we all know what microphone polar pickup patterns are, it just could be the perfect time to start researching the different types of microphones that utilize these pickup patterns. Lavalier microphones are a great place to begin.
A lavalier microphone is a really small microphone that’s attached either to an actor’s body or clothes. They come in both wired and wi-fi varieties and are designed to be discrete and lightweight. A wired lav could restrict an actor’s movement, however, a wi-fi lav mic requires only a small transmitter pack that’s usually clipped onto an actor’s belt or of their pocket.
Wireless lavalier microphones transmit their audio feeds via radio frequencies directly to a receiver that a sound mixer can control and regulate. There are lav microphones of widely various qualities available but the perfect choices will produce audio that rivals a standard boom mic.
Pickup Patterns and the Proximity Effect
The proximity effect is a phenomenon that results in an increase in low-frequency response as you move the mic nearer to the source. The nearer you get, the bigger the bass boost. This may create issues, but at the same time it opens up ways to shape the sound.
The proximity effect is what helps DJs on the radio to have really deep voices, and lots of a singer would sound like the skinny child he’s if it weren’t for the blessings of the proximity effect. Nonetheless, the proximity effect also can compromise speech intelligibility and make the low-end sound muddy, when “fattened” vocals and guitars get in the best way of bass and kick drum.
So the proximity effect is a good friend and an enemy at the same time. You need to use it to make things big, fat, and sexy, however, you need to keep it in check for great overall stability and maximum transparency. Clearly, the proximity effect is most noticeable in sounds with lots of low-frequency content material below 200 Hz. So it’s a vital factor when you record male voices, especially in the lower range, but it surely’s of much less consequence for female voices.
Conclusion
So now that all of the basics of microphone polar patterns, it’s time to place this knowledge into practice. While all these facts could also be simple enough in concept, the one way to actually get a really feel for microphone polar patterns is to experiment.
Take some time to record different signals, with different polar patterns, in different rooms and listen to the variations in every combination. Finally, you get a really feel for what works and what doesn’t.
If you read carefully in order to gain an excellent fundamental understanding of microphone pickup patterns then you definitely now are able to deal with any residence or studio situation that might pop up.
