dbx FCS966 30 Band Graphic EQ

Graphic equalizers are found in just about every sound application, from room contouring to feedback control and general audio sweetening.

Traditionally, much general EQ'ing takes place on the faders alone, but this restricts the use of the faders at each end of the scale for further precision eq work. So dbx provided the Opal FCS-966 with separate LF and HF contour filters which can change an overall sound balance without disturbing a detailed room or loudspeaker response.

These filters are very musical gentle boost and cut shelving filters which can be used to add (or remove) room effects that change with temperature, audience numbers or humidity.

All these effects can be easily made without disturbing the critical fader settings already made.

The modern generation of graphic EQs use the Constant Q topology, pioneered by dbx, which means that the filter width is constant whatever the fader gain setting.

Compared to the earlier 'gyrator' style of filters, Constant Q filters provide a smoother and more predictable interaction between adjacent faders and the resulting EQ curve more closely resembles the actual fader positions.

Each EQ fader has +/-15dB of adjustable gain, more than many competitive graphic EQs. The faders are long-throw 45mm types for precision control.

Also provided on the FCS-966 is a sweepable high-pass filter which can be used very effectively to restrict the low-energy output for better amplifier and loudspeaker performance. Stage monitors also benefit from the application of a high-pass filter to remove bass signals e.g. from vocal-only wedges.

dbx believes in providing engineers with information, and the FCS-966's 8-segment led meter shows output level and warns of signal clipping within the EQ. When the unit is switched to bypass, the meter will read the input level, allowing accurate matching of the 'dry' and equalised signals using the gain control.

When any EQ fader is in its center detent position, the filter is automatically bypassed, for optimum performance.

All the inputs and outputs of the FCS-966 are electronically balanced, with optional transformer balancing. To make installation of the FCS-966 easier, dbx has provided three differerent interface connectors: XLR-type, 1/4" TRS jack and Phoenix/Combicon screw terminals.

The EQ IN buttons switch the EQ path into circuit. When switched out, or power fails, a high-quality relay switches the input signal directly to the output connectors.

• 30 EQ filter faders on ISO centres, each with nominal +/-15dB of gain. Positive centre-detent on 45mm long-throw precision faders.

• Sweepable high pass filter, frequency adjustable from OUT (flat) up to 250Hz.

• Smooth shelving filter, +/-6dB of gain at 50Hz

• Smooth shelving filter, +/-6dB of gain at 14kHz.

• Used for overall unity gain adjustment. Adjustable from - infinity to +10dB.

• Triple-point clip detector that indicates red when the internal signal is clipping at any one of three critical points.

• Shows output signal level (input signal when eq is bypassed) from -24dBu to +18dBu in 8 steps.

• Chassis: 3U rack spaces
• Input Connectors: XLR, TRS, Combicon (2 each)
• Output Connectors: XLR, TRS, Combicon (2 each)
• EQ Bands: 30 per channel (60 total)
• Filter Width (Q): Constant-Q
• EQ Gain: +/- 15dB per band, plus - inf to +10dB overall
• Metering: 8-segment LED per channel
• Bypass Switch: yes
• High-Pass Filter: Sweepable, flat to 250Hz
• Low Frequency Contour: Smooth shelving filter, +/- 6dB at 50Hz
• High Frequency Contour: Smooth shelving filter, +/- 6dB at 14kHz