The S1 uses a VCA detection circuit on a selected frequency band to detect the signal peaks and boost the stereo spread accordingly.

The image will be made wider during high-energy transients to prevent phase knockbacks.

You can choose and blend between different imaging algorithms, from haas delay or classical mid-side equalization to the emulation of SRS transfer functions.

The input signal is first fed to a detection circuit that reacts to the average loudness of the song, where:

• Threshold controls the minimum peak detection,
• Speed controls the intertia of the moving average from the detection circuit,
• Low Pass allows to filter the input detection signal with a biquad low pass filter.

This detection circuit is used to dynamically adjust the stereo image of the sound:

• High pass and Low Pass allow to reduce the stereo adjustments to a single frequency band,
• Peak gain is the stereo gain that will be applied when the detection circuit hits his maximum value,
• Circuit allows to choose and blend between different imaging algorithms: binaural delay (Haas), head-related transfer functions (SRS) and mid-side boost (M/S).

A post processing step allows to adjust the final render:

• Makeup applies a negative makeup gain to compensate the induced stereo variance by reducing its average value,
• Comp reuses the input detection circuit to apply a touch of VCA compression to the signal sides.