The SPL Auto-Dynamic De-Esser is a highly specialized yet simple-to-use audio tool for removing undesired sibilant frequencies in a musically appropriate way without compromising the timbre and natural character of the voice.

SPL Auto-Dynamic De-Esser features a unique circuit design that combines ease of use with natural sound characteristics and the highest level of technical performance. Traditional de-essers use compression techniques. In addition to the threshold parameter used to set the processing level, there is a frequency controller for setting the centre frequency of the process (with bandwidths generally up to 4 kHz). Processing, therefore, compresses the entire selected range, not just the sibilant or S sounds. This results in familiar and undesired side-effects such as lisping and a nasal-sounding vocal.

SPL Auto Dynamic De-Esser monitors the entire frequency spectrum and automatically detects the sibilant frequencies. The bandwidth is set so narrowly around the range of the sibilance that neighbouring frequencies remain unaffected. This frequency band is mixed back into the main signal phase-inverted to cancel out the sibilance. The result is a sound-neutral, inconspicuous and extremely effective process. Even at high s-reduction values, the de-essing has a negligible effect on the character and timbre of the voice.

Rounding our this outstanding concept is an automatic threshold-adjusting function: Differences in the input level caused by the singer moving in relation to the microphone are automatically compensated so that the selected reduction value remains constant. In traditional de-essers, the processing intensity drops off with increasing distance, and compressors placed after the de-esser for signal correction tend to respond incorrectly to the changed values.

The SPL system doesn't just look for sibilance in a wide 'general sibilance' region of the spectrum. Instead, the user simply sets a front-panel switch to Male or Female to adjust for the vocal characteristics of male or female voices.

The SPL Auto-Dynamic De-Esser features symmetrical XLR and jack plugs for the in- and outputs, internal power supply with toroidal transformer, GNDlift switch, relay hard bypass/power fail safety, voltage selector switch.