Microphones and miking techniques - Miking of musical instruments

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Each musical instrument has its own peculiar characteristics and therefore miking must be adapted to each type of instrument. When a microphone is positioned to pick up the sound of a musical instrument one must bear in mind various different factors. One thing is essential: to strive for as faithful a reproduction of the instrument as possible. Therefore one must consider the frequency-content of the sound, the direction of its issuing, possible disturbing noises from other instruments in close proximity, possible reflections. The following are possible solutions for the miking of the most common musical instruments. We will describe the most common miking techniques bearing in mind that mike positioning is an art that improves with experience and, like any art, leaves a lot of space for imaginative solutions.

  • Drum-kit: the following is the standard solution:

    Microphones and miking techniques - Example of the miking of a drum-kit

    Example of the miking of a drum-kit

    For each part of the drum-kit a microphone is set up.

    • (1) Bass drum (dynamic)

    • (2) Snare drum (sensitive dynamic)

    • (3) Hi-hat (condenser)

    • (4) Tom 1 (sensitive dynamic)

    • (5) Tom 2 (sensitive dynamic)

    • (6) Floor tom (sensitive dynamic)

    • (7) (8) Crash cymbals (two condenser microphones placed with a stereo technique of one's own choice in order to pick up the stereo sound of the whole drum kit. These two mikes are known as overhead mikes).

  • Acoustic Guitar: both dynamic or condenser microphones can be used, according to the engineer's own choice. The microphone is directed towards the body of the guitar, next to the wood. It's important to not position the microphone next to the circular hole, seeing that air comes out of this hole when the body vibrates. By putting the microphone in such a position one risks picking up the sound of moving air rather than the acoustic guitar's sound. If one wanted to, the microphone could be placed next to the neck of the guitar to pick up the sound of the fingers moving across the fret-board, thus giving the recording a touch of realism (clearly in the mixing phase this sound will be added, but its presence should be very discreet). One could also place a microphone next to the side of the guitar's body:

    Microphones and miking techniques - Example of the miking of an acoustic guitar

    Example of the miking of an acoustic guitar

  • Electric guitar (Electric bass): the true sound of an electric guitar or an electric bass is the one that comes out of an amplifier. Therefore, often when recording these instruments a dynamic microphone is placed next to the amplifier's cone. With any amplifier's cone the closer we move towards the centre the more high frequencies we encounter. This is because high frequencies propagate from the coil to the cone towards its centre; they dwindle as they are diffused towards the outside. So, generally speaking, to pick up a signal that is as similar as possible to its real sound, one positions the microphone towards the central part of the cone. The guitar's amplifier plays a major role in colouring the guitar's sound, and if we want a sound that is closer to the original sound of the instrument a DI Box [Direct Injection Box aka DI box ] can be employed. One can even mix the two sounds (microphone, DI box) to get a composite sound.

  • Brass instruments: for these instruments (trumpets, trombones, sax etc.) it is important to remember that at the cone's exit, along the sound's main direction of propagation, there is a higher high-frequency content than in the areas that are slightly outside its path:

    Microphones and miking techniques - Example of miking of brass instruments

    Example of miking of brass instruments

    Another important thing to consider is that these instruments give off an annoying blowing-sound due to the air that passes through the instrument's mechanics and which isn't transformed into sound. The positioning of the microphone with these instruments is crucial for the reduction of these disturbances which are difficult to deal with during the mixdown.

  • Flute: the following diagram illustrates a typical miking of a flute:

    Microphones and miking techniques - Example of the miking of a flute

    Example of the miking of a flute

  • Violin: the following diagram illustrates a typical miking of a violin:

    Microphones and miking techniques - Example of the miking of a violin

    Example of the miking of a violin

  • Piano: with vertical pianos choices are quite few. The most common solution is to position two microphones as illustrated in the diagram, with a stereo miking technique:

    Microphones and miking techniques - Example of the miking of a simple piano

    Example of the miking of a simple piano

    As far as grand pianos is concerned, there are various solutions to choose from. The most simple is to once again use two microphones with a stereo miking technique. A more elaborate solution is illustrated in the following figure, where as many as 8 microphones are used:

    Microphones and miking techniques - Example of a complete miking of a grand piano

    Example of a complete miking of a grand piano