The DBX 902 is one of the best de-essers ever made, and remains in demand today, long after it was introduced.
The 902 examines the differences in dB between the high frequency and full-bandwidth portions of the signal, allowing de-essing of signals which change in level by as much as 60 dB. Conventional de-essers require readjustment of their threshold control when a vocalist drops from singing voice to a whispering voice. By contrast, the 902 does not even have a threshold control to require adjustment.
User-Defined Crossover Frequency/HF Only or Broadband Operation: The two-pole, maximally flat filter design used by the 902 in separating high frequencies from low frequencies can be user adjusted over a range of 800 Hz to 8 kHz. This, in conjunction with the HF only mode, enables the 902 to be used for special, non-vocal applications such as removing “clicks” from a close-mic’d guitar.
RMS Level Detection: dbx patented RMS level detectors enable the 902 to sense level on the same basis as the human ear -- providing a natural and accurate response to audio waveforms.
Other features include Control Voltage Inputs and Outputs, Expanded Scale LED Metering and Hard-Wired Bypass Switch.
Input Impedance: 20 k½ balanced, >10 k½ unbalanced
Output Impedance: 22 k½, into 600 ½ or greater
Maximum Input Level: +24 dBu
Maximum Output Level: +24 dBu into 600 ½ or greater
Frequency Response: 20 Hz - 20 kHz (+0/-3dB)
Dynamic Range: 115 dB
Distortion: Typically .008 % at 1 kHz
Equivalent Input Noise: -90 dBu, 20 Hz - 20 kHz Bandwidth, unweighted
Attack Rate: Program-dependent, 2 ms for 10 dB above threshold, 600µs for 20 dB above threshold, to achieve
63% gain reduction
Release Rate: 925 dB/sec
De-Essing Range: Operates uniformly over input range of -40 dBu to +24dBu without requiring adjustment
Maximum “Ess” Attenuation: Variable 0 to 20 dB
De-Ess Crossover Point: Variable 800 Hz to 8 kHz
Filter Type: 12 dB/ocatve, phase coherent
Controls: Frequency, Range
Switches: IN/OUT, Mode (HF ONLY/NORMAL)
Indicators: IN/OUT, HF ONLY
Metering: LED Column: 1, 2, 3, 4, 6, 8, 10, 12, 15, 20 dB gain reduction
Power Supply Requirements: ±15 V Regulated at 60 mA; ±24 V unregulated at 30 mA
Dimensions: Front Panel: 3U high (54”, 13.4 cm) x 12” W, (3.8 cm); card depth behind front panel: 92” (24.2 cm)
The Gear Rack