Yamaha AW4416 Reference Guide - Page 162

Appendix Compander Output Level dB +20 +10 0 -10 -20 -30 -40 -50 Width Threshold A compander is a compressor-expander-a combination of signal compression and expansion. The compander attenuates the input signal above the threshold as well as the level below the width. For very dynamic material, this program allows you to retain the dynamic range without having to be concerned with excessive output signal levels and clipping. CompanderH (CPH) and CompanderS (CPS) parameters: -60 -70 -70 -60 -50 -40 -30 -20 -10 0 +10 +20 Input Level Parameter dB Threshold (dB) Ratio Value -54 to 0 (55 points) 1.0, 1.1, 1.3, 1.5, 1.7, 2.0, 2.5, 3.0, 3.5, 4.0, 5.0, 6.0, 8.0, 10, 20 (15 points) Attack (ms) 0 to 120 (121 points) Outgain (dB) -18 to 0 (36 points) Width (dB) Release (ms) 1 to 90 5 ms to 42.3 sec*1, 6 ms to 46.0 sec*2, 8 ms to 63.4 sec*3 (90 points) (160 points) *1. These values are obtained when the sampling frequency is 48kHz. *2. These values are obtained when the sampling frequency is 44.1 kHz. *3. These values are obtained when the sampling frequency is 32 kHz Threshold determines the level of input signal required to trigger the compander. Signals above the threshold pass through unaffected. Signals at and below the threshold level are attenuated by the amount specified using the Ratio parameter. The trigger signal is determined using the KEY IN parameter. Ratio controls the amount of companding-the change in output signal level relative to change in input signal level. With a 2:1 ratio, for example, a 10 dB change in input level (above the threshold) results in a 5 dB change in output level. The hard compander (CPH) has a fixed ratio of 5:1 for expansion and the soft compander (CPS) has a fixed ratio of 1.5:1 for expansion. Attack controls how soon the signal is companded once the compander has been triggered. With a fast attack time, the signal is companded almost immediately. With a slow attack time, the initial transient of a sound passes through unaffected. Out Gain sets the compander's output signal level. Width is used to determine the distance, in decibels, between the expander and the compressor. With a width of 90 dB, the expander is effectively switched off and the compander is simply a compressor-limiter. With a smaller width (30dB) and a high threshold (0dB), the compander is an expander-compressor-limiter. Release determines how soon the compander returns to its normal gain once the trigger signal level drops below the threshold. 27 - Reference Guide Appendix-