Housed in a convenient 500 series lunchbox-style chassis, the dbx 520 De-Esser is designed to tame excessive sibilance sounds which often occur in vocals and other high frequency content such as percussive instruments and problematic material with heavy amounts of reverb.
 
Drawing from the design of the dbx 902, the unit allows you to adjust the amount of de-essing to create crisp vocals.The unit operates by examining the difference in level between high frequency and full-bandwidth portions of the signal. It allows de-essing of signals by as much as 60 dB. The unit features a frequency control with a range from 800 to 8,000 Hz with gain reduction metering and a de-essing amount range from 0 to 20 dB. It also includes an In/Out switch for comparing the processed and unprocessed signals, as well as a High Frequency (HF) mode switch.