DBX 520 De-Esser - 500 Series - DBX520

Product Overview

The DBX 520 is a 500-series de-esser module that uses a dbx VCA gain cell and program-dependent processing to reduce sibilance and high-frequency harshness in vocal and instrumental recordings, operating in a single 500-series module slot. The 520 provides two de-essing modes — broadband and frequency-selective — allowing the engineer to apply gain reduction either across the entire signal or only in the frequency range where the sibilant energy is concentrated. Variable frequency control from 800 Hz to 16 kHz and a 12-segment gain reduction display make the 520 a precise and transparent sibilance control tool for recording studio, broadcast, and mastering applications.

Product Description

The DBX 520 de-esser uses a high-speed dbx VCA gain cell in the side chain to detect and reduce sibilant energy, providing consistently fast response times that address individual sibilant transients without audibly affecting the surrounding program material. The variable frequency control sweeps continuously from 800 Hz to 16 kHz, allowing the engineer to identify and target the exact frequency range where the sibilant problem is most severe for the specific microphone and source combination in use.

In broadband mode, the 520 applies gain reduction across the full signal bandwidth whenever the detector detects sibilant energy above the detection threshold. In frequency-selective mode, gain reduction is applied only within the frequency band centered at the selected detector frequency, leaving the rest of the spectrum unaffected. Frequency-selective mode is generally preferred for transparently controlling sibilance on a finished recording without audible tonal side effects, while broadband mode is useful for more aggressive control of highly sibilant sources during tracking.

A 12-segment gain reduction LED display provides continuous visibility of de-essing activity, and a front panel in/out switch allows instant bypass comparison. The 520 operates on +/-16V DC from any standard 500-series power frame and draws only 1.6 watts, making it thermally efficient in fully loaded racks. Available at Creation Networks for vocal recording, broadcast, mastering, and live sound applications.

Key Features

• Broadband and Frequency-Selective Modes — Switchable between full-bandwidth gain reduction and frequency-specific gain reduction for transparent or aggressive sibilance control.
• Variable Frequency Control 800 Hz to 16 kHz — Continuously adjustable detection frequency targets the exact sibilant peak of any source and microphone combination.
• dbx VCA Gain Cell — High-speed VCA provides fast, accurate gain reduction response to individual sibilant transients.
• 12-Segment GR Display — Continuous gain reduction metering for visual confirmation of de-essing activity and depth.
• In/Out Comparison Switch — Instant bypass allows accurate before/after comparison of de-essing effect.
• Single-Slot 500-Series Format — Fits any standard 500-series compatible power frame; draws only 1.6 watts.

Typical Applications

• Recording studio
• Broadcast studio
• House of worship
• Auditorium
• Mastering studio

Technical Specifications

Frequently Asked Questions

Q: What is the difference between broadband and frequency-selective de-essing on the 520?

In broadband mode, the 520 applies gain reduction across the full signal bandwidth whenever the detector detects sibilant energy above threshold — effectively compressing the entire signal when sibilance is present. In frequency-selective mode, gain reduction is applied only within the band centered at the selected frequency, leaving the rest of the spectrum unaffected. Frequency-selective mode is generally more transparent.

Q: What frequency range does sibilance typically occur in?

Sibilance typically concentrates between 4 kHz and 10 kHz, depending on the microphone and vocalist. The 520's frequency control sweeps from 800 Hz to 16 kHz to accommodate a wide range of microphone and source combinations.

Q: Can the 520 be used on instruments other than vocals?

Yes. The 520 can be used on any source with excessive high-frequency content, including acoustic guitars, cymbals, hi-hats, and string instruments. The variable frequency control allows the detection point to be matched to the specific frequency range of the problem.

Q: Does the 520 have a side chain listen function?

dbx does not publish a side chain listen function for the 520. Setting the detection frequency can be accomplished by ear using the gain reduction display as a visual guide to confirm the detector is responding to sibilant activity.

Q: Is the 520 compatible with all 500-series frames?

Yes. The 520 is compatible with any standard 500-series compatible power frame, occupying one slot and drawing 50 mA per +/-16V rail.