The more we create and share resources with others online, the more important it is to make sure that our voices are heard…literally. Choosing the right microphones, recording room setup and techniques, and audio file formats can make a startling amount of difference. This article is the first in a series that will help you know what to look for, what to avoid, and how to get the best sound wherever you are. This time around, we’ll focus on microphones.
The first step in recording good audio is choosing the microphone that will be listening to you. Every microphone has a particular pattern in which it receives sound waves from an audio source, called a pickup pattern. The most commonly used types of microphones are omnidirectional, bidirectional, cardioid, and shotgun.
Omnidirectional microphones pick up sound in a completely circular pattern. They are most useful if everything in a room needs to be recorded, such as the sound of a classroom or lecture hall where there may be many speakers, or where the speaker may move around. An omnidirectional pickup pattern looks like this:
As you can see, this microphone would be useful either on a stand facing upward in the middle of the room, or perhaps hung from the ceiling. It’s not great for recording sounds if just one person is talking in a stationary position, or if there is the potential for unwanted background noise interference.
Bidirectional microphones pick up sound at two poles only, and don’t pick up sound from the middle. A bidirectional pickup pattern looks like this:
They are useful for two speakers at the same time facing opposite one another (the most obvious case). They are also useful for recording two discrete sources from the same microphone, such as a singer who also plays guitar, or for recording one sound source with old-fashioned stereo separation (with no pickup in the middle of the microphone, everything will be hard right or hard left in your headphones). They are not great for recording a single stationary speaker, since the microphone will be capturing in a direction that has no sound source.
Cardioid microphones are named because their pickup pattern resembles a heart. They pick up primarily from the front, but also from the sides to a lesser degree, and almost nothing from the rear. This is the workhorse of microphones, and the most common pickup pattern overall. If you have ever spoken or performed on stage with a mic in your face, there’s at least a 90% chance that this is the kind of mic you’ve used. A cardioid pickup pattern looks like this:
Cardioids are useful for recording voices, instruments, or anything where there is a single, stationary sound source. As you can see, it not only captures what is coming directly into it, but picks up some of the sound going around the mic, making it easy to record in full stereo. It’s hardly subject to any interference from background noise, as it pretty much picks up one thing only. There are a couple of additional variations on the cardioid—the supercardioid and the hypercardioid—that offer a little bit of pickup in the rear, but these are basically blends between the standard cardioid pattern and bidirectional or shotgun patterns.
Shotgun microphones are a specialized type of microphone that offers a very tight pickup pattern, primarily aimed forward, that picks up sound in a very narrow range. They are useful in situations where there is a lot of background noise interference, like recording outside or in a crowd. A shotgun mic’s pickup pattern looks like this:
This is the microphone you see when the boom comes into the picture on a news broadcast, or in a television show blooper, usually when the speaker is outside or broadcasting from a crowd. You’ll notice when listening that there is a little bit of crowd or nature noise, but you can hear the source surprisingly well considering all of the interference around it. This is because of the narrowness of the pickup pattern; it’s only really interested in what is directly in front of it.
Choosing The Right Microphone
So which microphone should you choose for your situation?
- If you are just going to be recording yourself in a quiet room, a cardioid will do the job just fine. This is what the average desktop mic will be, and what the mic in your laptop is. If you use a headphone mic to record, you are either using a cardioid or shotgun mic, as they need to be very focused to cancel the noise around you.
- If you will be outside or in a group of people, try a shotgun. You will get a lot more you and a lot less them.
- Interviews can work very well with a bidirectional microphone, because the speakers can sit across from one another and be separate sources into one microphone.
- If you just need a general area mic to pick up all the sound in a room, and some background noise is okay, use an omnidirectional mic.
Many microphones nowadays can switch pickup patterns to adapt to different recording situations. If you are planning on buying a desktop microphone, this is a good feature to look for, but if you have to choose, choose cardioid. It’s the easiest to use and will fit the widest variety of situations.
Placing Your Microphone
Where should your microphone be placed when you record? The greatest mic in the world will still give you bad audio if your source isn’t properly set up. Ideally, your microphone should be a few inches in front of your face, and you should be speaking directly into the pickup pattern. There is no hard and fast rule about this, so try out some different distances and see how you sound best.
The classic microphone pose you see on television, where someone holds a cardioid microphone vertically against his/her chest, is totally wrong. The cardioid is trying to pick up sound emanating from the bottom of the person’s chin, while at the same time they are speaking perpendicular to it! Little sound gets picked up this way since your sound source is weak, and the sound engineer usually has to crank up the volume a lot to hear you at all, which then can result in unpleasant feedback.
Some people put the microphone very, very close to their mouths, like less than an inch away. This is also not a great idea—besides sounding a bit creepy like a movie monster, every last consonant like ‘p’, ‘c’, ‘k’, etc., will be greatly amplified and can ruin an otherwise good take.
Check Your Levels
Once you have the right mic, in the right place, the final step is to check your levels. Whatever computer program you will be recording with should have a level meter that will indicate the relative loudness of the signal coming through the microphone.
- Do a microphone check by speaking a few sentences in your normal voice, at normal pace and volume. Watch the level move as you talk. Ideally, you will be in the middle of the range most of the time, with occasional louder peaks. A short blip into the red area or the high area is okay, but you don’t want to be talking at this level all the time. If you are continuously recording at peak volume, your sound signal can be distorted or even clipped off by the microphone because the source is too “hot,” or louder than the microphone itself is prepared to handle. Microphones do have limits, and if you exceed them, they will distort or simply cut off. If your signal is too hot, turn down the volume on your recording mic until you see it’s at a more pleasing level.
- Then talk about something you really like or dislike for a moment—this will likely raise the volume and pitch of your voice. Check and see that your signal doesn’t get too hot here, or adjust your volume again as necessary.
- Depending on what software you have, you may have an equalizer available to you. This can help you adjust the levels of bass or treble in your signal to produce a more pleasing effect. If you are recording a speaking voice, the adjustments tend to be minimal.
- If you have a particularly deep bass voice, it can help to roll back the treble a bit so that your voice isn’t as “boomy” on tape and you are easier to understand.
- If you have a very high treble voice, you may want to bring up the bass some to help a listener’s comprehension. Particularly in situations where there is noise in the background, a high voice can get lost in the mix and be hard to distinguish from crowd noise. The added bass will help separate your syllables, words and sentences.
- If you don’t have an equalizer right now, or don’t want to use it, don’t panic. We’ll talk about software tweaks to make you sound better in Part Two.
Remember: Source + Mic + Engineer (or software) = Audio. If any one of these components is poorly chosen or badly executed, it can ruin the results. We’ve just concluded talking about the source and the mic, and in Parts Two and Three, we will discuss the recording and editing process in more detail. Stay tuned!
This series will continue with Make Your Voice Heard, Part Two: Audio Recording and Effects.
All images courtesy of Wikimedia Commons.