How to Get the Best Sound from Your Musical Instrument
by Using the Right Microphone Placement - Part 3 -

Positioning Microphones

Placing a mic close in on an instrument increases separation and reduces background noise, but limits the tone’s ability to fully develop its natural sound. This is especially true at the lower frequencies. Yet with some mics it may produce an unnaturally “tubby” bottom-end due to the proximity affect.

With vocalists, a 3-inch distance may produce popping, and a closer positioning will make it worse. Using a side-address positioning will limit this proximity effect as well as the frequency response. Hey, those pop filters do work and if it’s a single vocalist overdub, back the mic off, or use an omni directional mic as they are less susceptible to low-frequency breath pops since they have no rear-entry port.

Any microphone “technique” used will depend on the following:
■ The instrument that’s being recorded
■ The tempo and pitch of the piece being played
■ The musician’s style of playing and whether it requires a more no interfering mic placement
■ The characteristics, especially proximity effect, of the available mics
■ The sound of the room’s acoustics due to its size, shape, reflections, and reverberation time
■ Any other instruments being played such as when the sound must be blended with the other members of a section
■ The amount of bleed from other sound sources
■ Whether or not you are using the microphone position to achieve a purist or natural sound, or to change or affect the instrument’s sound in some way- And on and on.

Besides, in addition to knowing the standard mic placement procedures, as a professional you need to develop your own methods. If the standard configuration works, great; if not, you’ll know what to do about it.

Years of experience and simply listening to the source will bring you a long way, but you also need to understand the way microphones, music instruments, and room acoustics function together in producing sound.

It’s obviously important that the instrument should be playable, hold tune, and produce an adequate sound, and that the mic used can handle the full frequency content and dynamic range. Less obvious is how the acoustic properties of the recording environment will affect a sound. That’s because you’re hearing the instrument in that acoustic space with your dual ear/brain combination, which works to compensate for most of the sound irregularities that you encounter.

Microphones, on the other hand, only have one “ear” and no brain so they pick up everything and that’s what you get. This will include the direct sound from the source, reflections from nearby structures, plus sounds from more distant sources such as reverb, HVAC noise, and a bleed from other instruments, all picked up from that one position.

The difference between sounds picked up by your hearing system and that of a cardioid microphone is remarkable. If you don’t believe me, stick a finger in one ear and give the world a listen. Better yet, use a soft in-ear hearing protector instead of your finger, but remember to keep that open ear at a distance from loud sound sources.

Hey, I always wanted to stick my ear close down to a snare or right in on a guitar speaker too, but that’s like a video color corrector staring at the sun. It’s not for someone who has any long-term professional goals! Or, as I like to put it, “You got to protect your money makers!”

Most microphone placement works when positioned from the perspective of the audience, or listener, that is, 3 to 6 feet in front of a music instrument. This makes sense as it takes into consideration the way an instrument was designed to project sound. Even though it will pick up information from reflections off the floor, walls, and other surfaces surrounding the instrument, a single mic only has one “ear” so it cannot provide the spectral information obtained by listening with our two ears.

Dual mic usage may be able to make up for this, but that’s not guaranteed and, as explained, this is often impractical as they can be cumbersome, introduce comb filtering, and add leakage from other sound sources.

The Musician’s Audio Recording Perspective

Try looking at the way a musician’s ears are aimed at the instrument: the violin family, a seated cellist, an upright bass player, or someone sitting at a grand piano. They are satisfied with the sound as they are hearing it, and while there certainly may be better positioning as far as instrument timbre is concerned, I have found this to be a very good starting position.

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