# Sidechain Gate

## Functionality

A sidechain gate acts like a normal (wideband) gate but has the ability to filter the detected signal before sendig it to the gain reduction stage.
Normally a gate uses the full range signal to detect a level above the threshold. A sidechain gate provides a filter (or equalizer) for the detection signal to reduce the bandwidth or to remove some frequencies from it. For example: If you cut all lower frequencies from your detection signal the gate will decrease the volume of your track only if not enough highs appear. With this technique you are able to reduce the resonation of a natural drum or remove "rumbling" of muted strokes from a heavily distorted guitar.

## Sidechain

Calf Sidechain Gate provides two independent filters to give complete control over the sidechain signal. You can listen to the filtered signal through the "S/C Listen" button to set the filters values exactly. The filters' LED's display the status of them. A blue light shows a bell or shelving filter, red light indicates a high-, low- or bandpass.

## Split

For denoising or derumbling you can choose a "split" mode from the list, too. While in this mode only one filter is set to active. Choose a split frequency with this one. The other filter is used internally to split the signal to be gated at the same frequency as the sidechain filter. After gating the chosen frequency range through the (also filtered) sidechain it is added to the untouched frequency range again. Split mode gives you the ability to reduce a defined frequency range without affecting other frequencies. For example if heavy compression of a snare drum raises its ringing mids to a long tone a sidechain gate can reduce just this frequency range to a short peak without any trailing sound again.

## More

For more information about gating and the essential values please refer to the gate's manual.

## Controls

- Bypass: Don't process anything, just bypass the signal
- Input (VU-meter): The level of the original signal
- Input (LED): Flashes if the level of the original signal raises above 0dB (it doesn't clip your signal)
- Output (VU-meter): The level of the compressed and made up signal
- Output (LED): Flashes if the level of the output signal raises above 0dB (it may clip your signal depending on your host and your systems' bitrate!)
- Max Gain Reduction: The level of gain reduction when the signal is below the threshold
- Gating: The level of reduction on the original signal
- Attack: Amount of milliseconds the signal has to rise above the threshold before gain reduction stops
- Release: Amount of milliseconds the signal has to fall below the threshold before the reduction is increased again
- Knee: Curve the sharp knee around the threshold to enter gain reduction more softly
- Ratio: Set a ratio about which the signal is reduced
- Threshold: If a signal rises above this level the gain reduction is released
- Makeup: Amplify your signal after processing
- Stereo Link: Choose if the average level between both channels or the louder channel affects the reduction
- Detection: Choose if the deesser should take the exact signal for detection or an RMS like one (it's mainly smoother).
- Gain Reduction: The level of reduction on the original signal
- Sidechain Mode: The selection of filters to use in the sidechain
- S/C Listen: Route the filtered sidechain signal to the output for monitoring purposes
- F1 active: Displays the status of filter #1: Off - off, blue - bell or shelving, red - band-, high- or lowpass
- F1 Freq: The frequency of filter #1
- F1 Level: Increase or decrease the chosen frequencies
- F2 active: Displays the status of filter #2: Off - off, blue - bell or shelving, red - band-, high- or lowpass
- F2 Freq: The frequency of filter #2
- F2 Level: Increase or decrease the chosen frequencies