"SPLs DE-ESSER is undisputedly the best representative of its kind." Keyboards (GER)

The SPL Auto-Dynamic De-Esser is a highly specialised audio tool for removing undesired sibilant frequencies in a very simple and musical way without compromising the timbre and natural character of a voice.

To solve this difficult problem, SPL has developed a new circuit design that combines ease of use with natural sound characteristics and the highest level of technical performance. SPL’s Auto Dynamic De-Esser monitors the S-frequency spectrum and automatically detects the sibilant frequencies. The de-ess bandwidth is set so narrowly around the range of the sibilance that neighbouring frequencies remain unaffected. Input processed via this frequency band is mixed back into the main signal phase-inverted so that only the S-sounds are cancelled where the S-reduction controller determines the intensity of the phase-cancelled mix. The result is a neutral, unobtrusive and extremely effective de-essing process. Even at high S-reduction values the de-essing has a negligible effect on the character and timbre of the voice.

Rounding out the amazingly simple control system is an automatic threshold-adjusting function. Differences in the input level caused by the varying distance to the mic, are compensated for automatically. This ensures even De-Essing independent of signal level so any necessary compression may be applied post the de-esser.

Specifications

Inputs and outputs:

Instrumentation amplifier, electronically balanced (differential), transformerless Nominal input level +6 dB Input impedance =22 kÙ Output impedance < 600Ù Max. input level +24 dBu Max. output level +22.4 dBu Minimum load 600Ù Relay hard bypass / power fail safety

Measured data Frequency response 20 Hz-50 kHz (50kHz= -3dB) Common mode rejection > -80 dBu @1kHz Total harmonic distortion 0.002% @ 1 kHz Signal-to-noise ratio -93 dBu (CCIR 468-3) Signal-to-noise ratio -98 dBu (A-weighted)

Power supply Toroidal transformer 15 VA Fuses (230/115 V) 315 mA/630 mA GND lift switch, voltage selection switch 115 V / 230V

Dimensions Standard EIA 19”/IHE 482 x 44 x 237mm Note: 0 dBu = 0.775 V