The S gate 4 is a versatile four channel Expander/Gate/Ducker that can be operated as four discrete gates or linked into two stereo pairs. The unit’s discerning circuitry provides precise frequency dependent triggering with two bands of highly accurate, selectable filters. Its handling of audio is fast and precise offering subtle control, and can be sonically invisible if so desired.

The S gate 4’s powerful Ducker feature allows the user to automatically lower the signal of a channel or stereo pair. You can also lower or "duck" the signal level by inserting an external source into the Key Input. This is especially useful for utilizing another audio source, such as a solo instrument or voice-over to "duck," or regulate, a rhythm track or stereo program track. A Key Listen switch enables monitoring of the key signal.

The S gate 4’s Link switch allows the settings on channels 1 and 3 to control the processing of channels 2 and 4. In this mode, stereo Gating and Ducking can be accomplished easily. Each of the gate channels has High and Low Pass Filters, Threshold, Attack, Release, and Range Controls for precise manipulation. An 8-segment Gain Reduction LED allows the user to monitor the circuit’s effect. Ducker, Link, In/Out, Filter and Key Listen switches add increased versatility.