Yamaha CS1D Owner's Manual - Page 548

Appendices Gate Types GATE A gate, or noise gate is essentially an audio switch used to mute signals below a set threshold level. It can be used to cut background noise picked up by open microphones, noise and hiss from guitar valve amps and effects pedals, and leakage between drum microphones. It also has many creative uses too. For example, gating a drum sound with a short decay time tightens up the sound. Also, patching a gate into a droning bass synth channel and then triggering it from the kick drum channel allows the bass synth through only when the kick drum is struck, adding extra "oomph" on the beat. Output Level (dB) +20 +10 0 Threshold = -10dB -10 -20 -30 Range = -30dB -40 -50 -60 Range = -70dB -70 -70 -60 -50 -40 -30 -20 -10 0 +10 +20 Input Level (dB) Parameter THRESHOLD RANGE HOLD ATTACK DECAY Range -54 dB to 0 dB (1 dB steps) -70 dB to 0 dB (1 dB steps) 0.02 ms-1.96 s (fs = 48 kHz) 0.02 ms-2.13 s (fs = 44.1 kHz) 0-120 ms (1 ms steps) 5 ms-42.3 s (fs = 48 kHz) 6 ms-46 s (fs = 44.1 kHz) THRESHOLD-This determines the level at which the gate closes, cutting off the signal. Signals above the threshold level pass through unaffected. Signals at or below the threshold, however, cause the gate to close. The trigger signal is sourced using the KEY IN parameter. RANGE-This determines the level to which the gate closes. Think of it as a brick holding a garden gate open so that a certain amount of signal always flows through. For a setting of -70 dB, the gate closes completely when the input signal falls below the threshold. For a setting of -30 dB, however, the gate half closes. For a setting of 0 dB, the gate has no effect. When signals are gated abruptly, the sudden disappearance can sometimes sound odd. This parameter causes the gate to reduce the signal level rather than cut it completely. HOLD-This determines how long the gate stays open once the trigger signal has fallen below the threshold level. ATTACK-This determines how fast the gate opens when the signal exceeds the threshold level. Slow attack times can be used to remove the initial transient edge of percussive sounds. Too slow an attack time makes some sounds appear backwards. DECAY-This determines how fast the gate closes once the hold time has expired. A longer decay time produces a more natural gating effect, allowing the natural decay of an instrument to pass through. With a maximum decay time of between 42 and 46 seconds, you could even use this for fade-outs. 16