Plug It In! A Quick Guide to Live Vocal Microphones

By Jack Kontney

Choosing a microphone is a personal thing. A good live performance mic does more than just reproduce sound; it enhances your performance. More than that, it should feel good in your hand and it should look good on stage. Finding the right mic for your sound depends on a lot of things - the technical aspects of the mic, your particular voice, the venue, the engineer and so on.

So where do you start? The first and best place to start is by plugging in various microphones and trying them out in an environment that most resembles how and where you will be using them. For example, if you are not going to be singing through a guitar amp, then don't try it out on one. You'll want to hear your singing, not just "test, one, two." Obviously the best test is to try a mic out in a live performance. Next you need to understand some technical buzz words. Since these technical terms are often misunderstood, here is a quick layman's guide to the terminology with a bit of popular myth debunking.

Polar Patterns

Polar patterns, often called pick up patterns, define a microphone's sensitivity to sound from various directions. Virtually all live performance microphones are unidirectional, meaning that they maximize sound pick up directly into the microphone, while rejecting undesirable sounds. A microphone is better judged on the quality of it's directional pattern rather than its type. Engineers judge a mic'c polar pattern more on its consistency across all frequencies rather than its type. Some common unidirectional polar patterns are : cardioid, supercardioid and hypercardioid.

Microphone Cartridge Design

Microphone cartridges or elements regularly come in two common designs (a.k.a. mic's "operating principle") dynamic and condenser. These designs simply explain how the mic's engine works. Dynamic: By far, the most popular, dynamic microphones are generally more affordable, rugged and available. Condenser: The Other major microphone type, a condenser, typically costs more, historically was somewhat less rugged, and provides more precise sound. Now depending on the sound you are going for, capturing more nuance in your voice may or may not be what you want. Finally, as an important note, condensers require an outside power source or "phantom Power" in order to function. Phantom power usually comes from the mixing board.

Frequency Response

Frequency response is probably the most quoted and least understood microphone spec. So, lets first define it. Frequency Response is the measurement of a mic's sensitivity to sound (eg your voice) at different frequencies (pitches). Many people falsely believe that a wider frequency response denotes a better microphone. In live performance, this is simply not true. Why? Because concert sound systems ( even the best ones) don't reproduce sounds across the whole audio range. The quality or character of the mic is defined much more by the shape of its frequency response, rather than its response range. To determine if the shape is good for you, you need to try it out.

Proximity Effect

Present in all unidirectional microphones, proximity effect is the gradual increase in low frequency responses (low end "warmth") that occurs when the singer gets really close to the mic. Because this close range vocal style is flattering to many voices, this mic technique has become the norm in virtually all modern musical styles.

Presence Peak

Presence peak typically refers to a bump in the mic's frequency response ( for the sm58 from about 2kHz to 7kHz) which helps it to cut through the mix. This is a good thing for lead vocals, helping them remain intelligible amid the wash of all those instrumental bits.