Four Tips for Choosing Pro Microphones for Voice Recording

Part of the success of your web audio can be found in choosing microphones that accurately reproduce your voice. Whether you choose a mic by Shure, AKG, Audio-Technica, Rode, Sampson, or any other manufacturer, the brand of the microphone isn't as important as its ability to accurately capture sound.

First, look for a flat frequency response in the voice frequencies

The sounds produced in speech contain frequencies that lie within the frequency band of 100-10,000 Hz. However, the main useful voice frequencies are contained within the band 300 Hz to 3,400 Hz. The frequencies outside this narrower range contain harmonics which lend character to the sound of a voice.

Microphones with a uniform or "flat" frequency response in the key voice frequencies will capture the most appealing sounds in your voice. Pro mics differ primarily in how they handle the harmonic frequencies outside the key voice frequencies.

In the diagram above for the Shure SM57 , the lower harmonics (to the left of the red box) are diminished, while the higher harmonics (to the right of the red box) are given a boost in loudness. This boost will enhance the sibilance of a voice (the "s" and "sh" sounds in your voice).

In the diagram above for the Shure SM7B, the lower harmonics can be diminished by activating the mic's "bass rolloff" feature as seen by the dashed line to the left of the red box. (As you get closer to any mic, the lower frequencies and harmonics of your voice are enhanced. A bass rolloff switch cancels this enhancement.)

The SM7B also features a "presence boost" feature on the frequencies above 800 Hz as represented by the rising dotted line in the red box. This presence boost enhances the crispness and sibilance of your voice.

To repeat my main point, mics with a uniform or "flat" frequency response in the key voice frequencies will capture the most appealing sounds in your voice. Pro mics differ primarily in how they handle the harmonic frequencies outside the key voice frequencies.

Second, choose mics with a unidirectional, cardioid pattern

Unidirectional means "in one direction." Microphones with a cardioid (or "heart-shaped") pattern are designed to capture sound that is primarily in front of the mic while at the same time rejecting sound that is behind. Consequently, there will be less "room reverberation" captured when you record your voice.

Third, choose between condenser or dynamic microphones

The difference between mics is in their construction and how they process the sound signal. Condenser versions require external power (called "phantom power"). Many audio mixers and preamps offer phantom power.

Although there are exceptions, condenser versions tend to have a uniformly flat frequency response and a cardioid pickup pattern. They are great for capturing speaking voices. In fact, just about every radio station disk jockey, television reporter and voiceover artist in the world speaks into a unidirectional condenser microphone (although there are exceptions).

Dynamic microphones do not require any extra "phantom power" in order to work. Dynamic versions offer fairly flat frequency response and cardioid pattern as well. You tend to see music performers singing into dynamic mics when performing in concert. The best known dynamic version is the Shure SM58, which is used by almost every stage performer at one time or another.

Some Popular & Affordable Dynamic Shure microphone choices

Finally, choose a good microphone preamp

You can't just plug your professional microphone into your computer sound card and expect great sound. Because of technical things like "impedence matching", chances are you will get NO sound at all if you plug a pro mic directly into your sound card. You need to hook pro microphones to a mic amplifier ("mic preamp") before you can really use the mic correctly. You also need a good quality preamp. Most recording engineers will confirm that, all things being equal, a poor quality mic fed through a high quality mic preamp will tend to sound better than a high quality mic fed through a poor quality mic preamp.

Professional grade preamps tend to cost $800 US or more. Fortunately, there are some great preamps available for less than $300.

Read my review of affordable mic preamp selections