Adds a soft-clip limiter audio effect to an Audio bus. A limiter is similar to a compressor, but it's less flexible and designed to disallow sound going over a given dB threshold. Adding one in the Master bus is always recommended to reduce the effects of clipping. Soft clipping starts to reduce the peaks a little below the threshold level and progressively increases its effect as the input level increases such that the threshold is never exceeded. The waveform's maximum allowed value, in decibels. Value can range from -20 to -0.1. Applies a gain to the limited waves, in decibels. Value can range from 0 to 6. Threshold from which the limiter begins to be active, in decibels. Value can range from -30 to 0.