Yamaha 01V Owner's Manual - Page 170

Processor Types 167 Processor Types Dynamics processors are generally used to correct or control signal levels, although they can also be used creatively to shape a sound's volume envelope. The following sections explain the COMP, GATE, DUCKING, EXPAND, COMPANDER-(H), and COMPANDER-(S) dynamics processors, their parameters, and general applications. COMP The COMP processor is a compressor that attenuates signals above a specified threshold, +20 providing automatic level control. Vocalists +10 Compression ratio = 2:1 that tend to move toward and away from the 0 Output Level (dB) microphone while singing produce fluctuating signal levels; sometimes loud, sometimes -10 Threshold = -20dB -20 soft. Likewise, acoustic instruments with a -30 Knee = hard large dynamic range produce sound levels -40 from pianissimo (very soft) through to fortis- -50 simo (very loud). In these situations, it is -60 often difficult to set an average fader level that -70 will allow a voice or instrument to be heard clearly throughout a song or piece of music. -70 -60 -50 -40 -30 -20 -10 0 +10 +20 Input Level (dB) This is where the compressor comes in with automatic level control. By automatically reducing high levels, thus effectively reducing the dynamic range, the compressor makes it much easier to control signals and set appropriate fader levels. Reducing the dynamic range also means that recording levels can be set higher, therefore improving signal-to-noise performance. The COMP processor can also be used as a limiter, which is essentially a compressor with a high ratio setting. Compression ratios above 10:1 are considered to limit signals rather than compress them. When an input signal exceeds the specified threshold level, its level is automatically reduced to the threshold level. This means that the limiter's output level never actually exceeds the threshold level. Limiters are often used to prevent signals from overloading amplifiers and tape recorders. A limiter with a relatively high threshold, for example, could be used with the stereo outputs to prevent amplifier and speaker overload. Output Level (dB) +20 +10 Compression ratio = 20:1 0 -10 Threshold = -20dB -20 -30 Knee = hard -40 -50 -60 -70 -70 -60 -50 -40 -30 -20 -10 0 +10 +20 Input Level (dB) Parameter THRESHOLD OUT GAIN KNEE ATTACK RELEASE RATIO Range -54 dB to 0 dB (55 steps) 0.0 dB to +18.0 dB (0.5 dB steps) hard, 1, 2, 3, 4, 5 0-120 ms (1 ms steps) 5 ms-42.3 s (fs = 48 kHz) 6 ms-46 s (fs = 44.1 kHz) 1:1, 1.1:1, 1.3:1, 1.5:1, 1.7:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 5:1, 6:1, 8:1, 10:1, 20:1, ∞:1 (16 steps) 01V-Owner's Manual