COMPOSER PRO MDX2200
4.2.1 Controlling leakage in the studio
Expander/gates are most commonly used to suppress undesirable leakage of sound from one track to another during recording or playback. They are usually used when recording drum kits, where the mics are very close to each other. High volume levels of individual instruments often cause considerable leakage onto all the adjacent mics and results in conflicting frequency and phase coherence problems, as well as unspecified sounds (“comb” filter effects). It is vitally important that every instrument is recorded into a separate mic and that each mic is individually gated.
Patch the MDX2200 into a snare drum channel for example and adjust it so that triggering only occurs on snare hits. Each mic should be set to its maximum operating level, monitored (see SC MON switch) and the THRESHOLD level set so that each snare hit sounds acoustically clean and seperate, as though it was played on its own.
The optimum use of the expander/gate depends principally on microphone technique. Be particularly careful, when high frequency instruments are located to the side or rear of a cardioid microphone. Most cardioids exhibit a sharply rising
Please make full use of the directional characteristic of the mics, to acoustically exclude all other instruments as much as possible. Make sure that you do everything possible to achieve source separation with good microphone technique. Otherwise the expander/gate is not able to undertake clear acoustic separation.
Sometimes, it is necessary to prevent the expander/gate from responding to low frequencies (rumbles etc.), especially if a singer is moving the microphone around on a
4.2.2 Initial settings for the expander/gate section
Control | Setting |
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THRESHOLD control | OFF |
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RELEASE switch | SLOW |
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RATIO control | 1:2 |
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Tab. 4.1: Initial settings for the expander/gate section
Begin with very low threshold levels, so that the signal can pass through the unit unaffected. Now turn the control clockwise until all unwanted noise is removed and only the sound of the desired instrument can be heard.
To adapt the unit to the program material properly, you can additionally choose between a SLOW or FAST release time. In the depressed position, the unit works at a slow release time. Percussive material with little or no reverb, is processed in fast mode, whereas the slow mode is advantageously used for signals with long durations or signals with heavy ambience. You will find that a fast release time (FAST mode) is preferable for acoustic separation of most percussive sounds, whilst cymbals and tom toms, normally benefit from the SLOW mode.
The RATIO control determines the ratio between input and output level, for all signals below the selected point of threshold. Use this control to determine whether the section works as an expander or as a gate (Ratio 1:8).
If the controls are set correctly, the drum sounds will be “dry”, “sharp” and clearly defined. If you do not have enough mics (or COMPOSER PRO channels!) to record each instrument separately, try to create
The aim is to set up the expander/gate and to position the group mics so that each strike on an instrument opens a specific mic and so only that instrument is recorded, whilst the other mics remain “muted”.
4. APPLICATIONS | 17 |