Which Microphone Should You Use to Amplify Your Harmonica Sound?
As a harmonica player, you have many choices among vocal mics and mics designed for harmonica. The two most popular types used to amplify sound are vocal mics and bullet mics.
General purpose vocal mics
Vocal mics work well for harmonica. They deliver a clean, natural-sounding signal that can be processed to give a wide variety of sounds, from clean and airy to distorted and boxy.
When you look for a vocal mic, make sure that it has these characteristics:
Unidirectional response: This response pattern picks up sound only from the direction the mic is pointed in. This helps avoid feedback and picking up unwanted sounds.
Ease of holding and cupping: Make sure you can get your hands around the mic and that it isn’t too heavy to hold. And test it to make sure you can cup it without getting feedback.
Two characteristic of vocal mics that can affect the harmonica’s sound are:
Its frequency response curve. Every mic responds with greater energy to some parts of the audible spectrum of sounds. This information is often available as a graph called the response curve. In general, harmonica sounds better through mics that don’t emphasize the higher frequencies because the harmonica naturally outputs a lot of high frequencies, and a mic that emphasizes them can make the harmonica sound shrill.
The proximity effect. Some mics change their response as you get close to them or cup them, usually by giving greater emphasis to the midrange and lower frequencies. This can be great if you like the resulting change in the sound output. However, if you’re going for a clean, uncolored sound, you may want to choose a mic with little or no proximity effect.
Vocal mics often used by harmonica players include the Shure SM57, SM58, 545 series, and PE45, and the Electro-Voice RE10, while the Audix FireBall is a mic with no proximity effect that was adapted for clean, uncolored harmonica sound by altering a vocal mic design.
Bullet mics, named for their characteristic stubby, bullet-like shape, were designed to deliver spoken communications with maximum efficiency in noisy environments, such as bus stations. Blues harmonica players prize the harsh yet muted tonal colors of these primitive mics, together with the distortion they can get from a cupped bullet mic.
The two classic bullet mics are the Shure Green Bullet and the Astatic JT-30. Once cheap and commonly available, these models are rapidly becoming pricey collectors’ items. Modern imitations look cool and aren’t expensive, but they don’t deliver the classic sound.
Unless you have the bucks to spend on a well-maintained vintage mic or a custom job, you’re better off using a vocal mic and using effects and the amplifier itself to color your sound.