PC4K S-Type Bus Compressor module

Figure 480. PC4K S-Type Bus Compressor.

A. Clipping LED B. Compressor enable/disable C. VU meter D. Release E. Make-up gain F. Attack G. Threshold H. Sidechain High Pass filter I. Sidechain enable/disable J. Ratio K. Dry/Wet level

This is the default compressor module when using ProChannel on a bus. This module is based on the legendary center console stereo bus compressor in one of the world's most successful analog studio production mixing consoles. Known to add punch and drive to a mix. Also recommended for instruments like piano and drums. This mode supports sidechaining.

The PC4K S-Type Bus Compressor module contains the following controls:

Clipping LED. Shows if the input signal to the Compressor module is clipping. If there is any distortion in the ProChannel signal chain, the clipping LEDs let you identify where the clipping occurs.

Compressor enable/disable . Enables/disables the PC4K S-Type Bus Compressor module.

VU meter.  Shows the amount of gain reduction.

Thresh. Sets the level at which compression occurs. If the input signal level is below the threshold, no compression takes place. If the threshold level is reached, compression (i.e. automatic gain reduction) occurs, reducing the gain of the input signal according to the Ratio, Attack and Release settings. The valid range is -30 dB to +20 dB, and the default value is -10 dB.

Attack. Adjusts the time it takes the compressor to respond to the input signal after the threshold level has been reached. A fast attack setting means that compression will be more or less instant. Using a slower attack setting results in the compression being gradually increased, allowing for more variations in the signal than the fast setting. Attack should be adjusted according to the nature of the audio material. The valid range is 0.1 to 30 milliseconds, and the default value is 0.8 milliseconds.

Release. Adjusts the time the compressor takes to go back to an inactive state after the input level has fallen below the threshold value. Short release times will make the compression more flexible and able to adapt to the input signal, but can cause fast changes in gain that may sound displeasing to the ears. Longer release times produce a signal with a more even level and less distortion, but make it harder to maximize the overall compression because changes in the input level cannot be compensated for quickly enough to make the output volume totally consistent. The valid range is 0.1 to 1.2 seconds and Auto. and the default value is 0.5 seconds. If Auto is selected, the release time is dependent on the duration of the signal peak.

Make Up. Compensates, or “makes up” for automatic gain reduction. Make-up gain refers to the process of re-balancing the subjective level of the compressed audio against the uncompressed audio. In other words, make-up gain reduces the difference in level between the loudest and quietest sounds of the processed audio. As the compressor turns down the peak levels of the audio that exceeds the threshold level, you may want to turn up the level of the entire compressor to balance the mix. For example, if you increase the gain so that the peak levels are the same as before compression, the quieter sections of the audio will also be increased by the same amount, effectively keeping the peaks levels as they were before compression while increasing the level of the quieter audio. The valid range is -10 dB to +30 dB and Auto, and the default value is 0 dB. If Auto is selected, the Make Up gain is automatically calculated based on the Ratio and Threshold settings.

Ratio.  Controls the amount of compression (gain reduction) that will be applied to the signal after the input audio level exceeds the threshold level. Ratio denotes the difference in dB between input level and output level, i.e. how much the signal above the threshold level will be compressed. For example, a ratio of 4:1 means that when the input level increases by 4 dB, the output level of the signal above threshold will only increase by 1 dB. The following ratios are available:

2. Use when general dynamic range compression is desired.

4. Use when general dynamic range compression is desired.

10. Use when peak-limiting is desired.

Sidechain. Sidechaining is typically used with compressors to limit one signal depending on the signal level of another. Common applications are to reduce the level of a bass guitar when there is a kick drum, or to reduce the level of music whenever a speaker talks (often used for background music in radio- and television programs). Audio track, Bus and Send outputs can be routed to sidechain inputs. The Sidechain sections contains the following controls:

On/Off. Enables/disables the compressor’s sidechain input as an audio output destination in all Track/Bus/Send Output controls.

High Pass. Applies a High Pass filter to the sidechain input. The valid range is OFF to 2 kHz.

Dry/Wet.  Adjusts the balance between the unprocessed (dry) and processed (wet) audio signal. The range is 0 to 100% and the default value is 100%.

 

See also:

To sidechain the ProChannel compressor

 

See:

ProChannel

Using ProChannel

ProChannel modules and controls

PC76 U-Type Channel Compressor module

QuadCurve Equalizer module

Tube Saturation module

PC2A T-Type Leveling Amplifier

Softube Saturation Knob

Console Emulator module

FX Chain module

Tape Emulator module

REmatrix Solo convolution reverb

GRIT (saturation) module

MAX (volume maximizer) module

SPACE (reverb/ambience) module