Microphone Polar Patterns Explained
Introduction
Knowing about polar patterns is key to getting the best possible sound from your microphone. A polar pattern is a vital microphone specification that shows how sensitive the mic is to sound coming from different directions.
In this guide, you’ll learn everything you need to know to feel like a pro. If you don’t work with audio, the term “polar pattern” might be completely new to you. But understanding polar patterns—also called pickup patterns—is crucial when you’re picking the right microphone or microphones for any project. We’ll explain what a polar pattern is and break down the different types of patterns you might encounter.
What are polar patterns/pickup patterns?
A polar pattern shows how much sound a microphone can pick up from different directions. While it might seem a bit technical, a polar pattern simply explains a microphone’s natural directionality.
By choosing the right polar pattern, you can prevent unwanted sounds from getting into your recording, control the balance between direct and ambient sound, shape the frequency response, and affect the proximity effect. A polar pattern represents the area around a microphone where it is most sensitive to sound.
These patterns can be shown in three-dimensional space. Different microphones have different polar patterns, and these patterns help determine their ideal uses. Here are the five most common polar patterns, along with their basic polar pattern graphs:
1. Directional/Cardioid
The cardioid polar pattern is the most common type of directional polar pattern—the one shown in the example above. It gets its name because its response shape looks like a heart. Cardioid microphones are widely used when you want to focus on a single sound source while reducing pickup from the sides and rear.
A cardioid mic does a much better job of blocking out background noise and room reflections than an omnidirectional (Omni) mic. They are most commonly used in music production and live sound reinforcement. However, filmmakers may also encounter cardioid mics, especially in stereo microphones.
2. Omnidirectional
Omnidirectional microphones respond equally well to sound from all directions. Their coverage, or pickup angle, is a full 360 degrees, which brings several distinct advantages and disadvantages depending on how you use them.
On the positive side, omnidirectional mics produce a very natural and open sound, making them excellent for capturing the true character of instruments like acoustic guitars. However, omni mics also pick up more of the room’s ambiance, which can be a good thing as long as your room has great acoustics.
You can adjust the balance between direct sound and ambient room sound by changing the distance between the microphone and the instrument.
3. Bidirectional
Bidirectional microphones pick up sound equally well from both the front (zero degrees) and the back (180 degrees), but are least sensitive to sounds coming from the sides. This characteristic can be useful, for example, when recording two vocalists facing each other. However, most of the time, you’ll only use one side of the microphone.
The bidirectional polar pattern is also called the figure-8 pattern because the pickup area looks like the outline of a figure-8. With this type of microphone, you’ll capture audio from directly in front of and directly behind the capsule, while sounds coming from the sides are not picked up.
4. Hypercardioid
A hypercardioid pickup pattern is a directional pickup pattern that works well for isolating audio. While you might find some lavalier mics with hypercardioid pickup patterns, this pattern is most commonly seen in shotgun microphones.
Although each brand is different, the main difference between a hypercardioid mic and a supercardioid mic is how much sound they pick up from the rear and sides. Hypercardioid mics are typically used for recording instruments.
5. Supercardioid
Supercardioid microphones are the most popular choice for indie filmmakers because they allow users to isolate audio while still offering a bit of flexibility. Supercardioid pickup patterns are often found in shotgun mics, which are typically used on boom poles or mounted on top of a camera.
However, it’s important to note that a supercardioid pickup pattern will capture some audio from behind the microphone. So, if you mount a supercardioid mic to your camera, you’ll need to keep your operating noise to a minimum.
Best Polar Pattern For Podcasting
When recording a podcast or other home studio content, take some time to consider both your studio setup and your content. For most solo podcasts, a unidirectional pickup pattern will usually give you the best results. However, creative or unique podcasts might benefit from using a different pickup pattern.
Overall, your microphone’s pickup pattern is an important part of your podcast. If you think you’ll need to use more than one directional pattern often, you might want to invest in a microphone that lets you switch between patterns. Using two unidirectional cardioid microphones—one for the host and one for the guest—will likely capture higher quality audio for each person.
This way, you don’t have to worry about voices coming from different angles. However, keep in mind that you’ll now have two separate audio sources to manage during post-production.
Why Do Microphones Have Different Pickup Patterns?
Our ears can do all sorts of things: we can just hear what’s going on around us, or we can choose to listen very carefully. And sometimes, we simply tune things out because we don’t need to hear them. Microphones can do similar things!
Imagine you’re at a party where there’s music playing and people chatting. When you walk into the room, you take in everything at once. You notice the music in the background, hear people talking, and maybe even overhear your name in a conversation while greeting a friend.
It’s pretty incredible what we can do with just our ears! Of course, we also have a powerful signal processor—our brain—helping us out. Microphones, on the other hand, use different pickup patterns, since they don’t have a brain like we do.
Using Microphone Polar Patterns Effectively
How does this basic overview of microphone patterns and their characteristics actually help us make better recordings? Going back to our trusty cardioid mic, we now understand that we need to account for its less accurate off-axis frequency response and, when used very close to a sound source, the extra boost in bass due to proximity effect.
The directional qualities of cardioid microphones help keep instruments separated in the recording and also reduce the amount of reflected sound reaching the mic. However, any spill or reflected sound that does reach the rear and sides of the microphone will likely be noticeably colored compared to an omni mic used in the same situation.
An omni mic, of course, will pick up more of the room sound, but it does so with much less coloration than a cardioid. Using effective absorbers will greatly improve the quality of recordings made with a cardioid mic in a very reflective space, but few cardioids sound as natural as a good omni model. This is simply because the acoustic labyrinth behind the diaphragm in cardioid mics affects the purity of the sound.
What is a Lavalier Microphone?
Now that we all understand microphone polar pickup patterns, it’s a great time to start exploring the different types of microphones that use these patterns. Lavalier microphones are an excellent place to start.
A lavalier microphone is a very small mic that’s attached to an actor’s body or clothing. They come in both wired and wireless versions and are designed to be discreet and lightweight. While a wired lav mic can limit an actor’s movement, a wireless lav mic uses a small transmitter pack that’s usually clipped onto the actor’s belt or placed in their pocket.
Wireless lavalier microphones send audio through radio frequencies directly to a receiver, where a sound mixer can monitor and control the levels. There are lavalier microphones available in a wide range of quality, but the best ones can produce audio that rivals a standard boom mic.
Pickup Patterns and the Proximity Effect
The proximity effect is a phenomenon where the low-frequency response increases as you move the microphone closer to the sound source. The closer you get, the more pronounced the bass boost becomes. While this can sometimes cause problems, it also offers creative ways to shape your sound.
The proximity effect is what gives radio DJs their deep, rich voices, and it’s what keeps singers from sounding thin or weak—in many cases, their voices would lack presence without it. However, the proximity effect can also reduce speech intelligibility and make the low end sound muddy, especially when “fattened” vocals and guitars start to clash with the bass and kick drum.
So, the proximity effect is both a friend and a foe. You can use it to make sounds big, warm, and full, but you have to keep it under control for a balanced, clear mix. The effect is most noticeable in sounds with lots of low-frequency content below 200 Hz, making it especially important when recording male voices in the lower range. For female voices, it’s generally less of an issue.
Conclusion
Now that you understand the basics of microphone polar patterns, it’s time to put that knowledge into practice. While these concepts may seem simple enough, the best way to truly grasp how polar patterns work is to experiment with them yourself.
Spend some time recording different sounds, using different polar patterns, in various rooms. Listen to how each combination changes the sound. This hands-on experience will help you figure out what works best and what doesn’t.
If you’ve read carefully and have a solid understanding of microphone pickup patterns, you’re now prepared to handle any home or studio recording situation that comes your way.
