Your Guide To Microphones

Microphones. What are they and what do they do? How do I use them to get the best sound possible?

First things first – what do they do? In a sentence, a microphone takes sound waves from the air and converts them to electricity. This electric is recorded and stored, usually digitally.

How do they do that? Generally, a mic has a diaphragm that reacts to sound waves in the air. This is converted to electricity various ways, then sent down the cable. From there, it is recorded and stored by different methods.

For a bit more in depth look at it, see the Wikipedia article on microphones.

But there are dozens of mics looking at you, waving their arms and screaming, “Pick me! Pick me!” How do you decide which one? What should be your first consideration?

Here are a few features to help you which is the best one:

• transducer type
• pickup pattern
• body construction or diaphragm size
• suitability to sound source

Transducer type

What are the differences that I need to consider when shopping? In the range of mic types, sound quality and tone can be slightly affected. The dynamic has a rougher sound, while the condenser is more detailed.

Often condenser microphones are found in studios, while dynamics are seen in live performances and PA systems. This isn’t the rule, only a generality.

The dynamic can also take a tad rougher handling than a condenser, making it more suitable for travel and many setup-teardown phases.

Both are good choices, but try getting a condenser for your first one. Better yet, listen to both of them in action to decide which one you like best!

Pickup Pattern

• Cardioid
• Omni-directional
• Super Cardioid
• Hyper Cardioid
• Figure 8

The main difference is the direction that the mic is most sensitive in. There are directional styles, and omni-directional styles. (The omni part means all, so it picks up all around.)

What difference does this make to you? Let’s say you are recording a quartet of voices. You have 4 microphones, one for each singer. You might want to put 1 mic in front of each singer, so it picks up only him/her.

But, if the mic is an omni, it will end up recording all the voices. If you use a cardioid, it will pick up sound from the front only, so you can isolate that track from the others.

If you were recording in a big hall, and wanted to get a lot of the reverb sound from the room, you might use an omni to catch sound from all different directions.

What about a figure 8? That pattern picks up from the front and back, but not from the sides of the microphone.

What is different in the super and hyper cardioid from the regular cardioids? They are still directional microphones, but are more focused in the front. The trade-off is that a small amount of rear acceptance is let in. You might say that the super and hyper cardioid patterns are steps between a regular cardioid and a figure 8.

I need to say something with all this talk about directional mics. While a cardioid has good side and rear rejection, it will still pick up that sound. It just attenuates it, so you can pick a spot to accent.

So what kind should you get? If you want to do several mics at a time for an ensemble, I would go the directional route. After you have a few cardioid mics, then expand into the omni world, but always experiment.

Body construction

That seems fairly obvious, but it can make a difference.A large diaphragm can pick up low frequency sound better than a small diaphragm, because it can vibrate slower, and has a bigger surface.

Large diaphragms are usually found in side-address microphones. This means that it is set straight up, with the diaphragm pointed out the side. It has a large body, around 2 inches or so in diameter.

Smaller diaphragms will sound better on high frequencies, because the diaphragm can move faster. They sound a bit more detailed on the high range, but still good overall.

A larger diaphragm will also sound a bit fuller and warmer, due to the detail in the lower frequencies.

Which should you get? It depends a lot on what kind of recording you want to do. Vocals usually benefit from the warmness a large diaphragm can give. Classical ensembles and drums are usually mic’ed with small diaphragms.

Guitars are done with just about anything, so take your pick, or ask a friend what they use!

Suitability to sound source

Some bring out the sound of different instruments and voices better than others. But one mic is never the one! There just is no Swiss Army knife microphone! You can’t have a ‘one-size-fits-all’ mic.

Some kinds can come close, so use your judgment and a trusted recommendation for your first mic, if you will use it for a variety of purposes.

When looking at specific microphones, read reviews from other people. Check what they are advertised to work with the best. See what your gut feeling says.

And have fun!

Mic Placement/Technique

Simple! Just read my page on mic placement and technique. It's part of a series on voice recording, and I recommend you look at the whole series, starting here.