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BSS FCS-966 Graphic Equalizer

  • Product Highlights
  • Long 45mm Faders
  • Center Bypass
  • Constant Q Filters
  • High-Pass Filter
  • More Gain Control per Filter
  • 8-Segment LED Meter
  • Channel Bypass Selection
  • Balanced Inputs & Outputs
You Pay: $1368.46 QTY
  • Product Highlights
  • Long 45mm Faders
  • Center Bypass
  • Constant Q Filters
  • High-Pass Filter
  • More Gain Control per Filter
  • 8-Segment LED Meter
  • Channel Bypass Selection
  • Balanced Inputs & Outputs

Constant Q Graphic EQ


BSS Audio provides the Opal FCS-966 Constant Q Graphic Equalizer with separate LF and HF contour filters that can change an overall sound balance without disturbing a detailed room or loudspeaker response. Graphic equalizers are found in just about every sound application, from room contouring to feedback control and general audio sweetening. With the Opal Constant Q you're able to make greater use of the faders at each end of the scale for precision EQ work in a wider range of settings.

These filters are very musical gentle boost and cut shelving filters that 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.

Constant Q Filters
The modern generation of graphic EQs uses the Constant Q topology, pioneered by BSS Audio, 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.

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

High-Pass Filter
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).

BSS Audio 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 equalized signals using the gain control.

Center Bypass
When any EQ fader is in it's 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, there are three different interface connectors: XLR-type, 1/4" TRS jack and Phoenix/Combicon screw terminals.

Relay Bypass
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.

Control Descriptions
- Faders - 30 EQ filter faders on ISO centres, each with nominal +/-15dB of gain. Positive center detent on 45mm long-throw precision faders
- HP Filter - Sweepable high pass filter, frequency adjustable from OUT (flat) up to 250Hz
- LF Contour - Smooth shelving filter, +/-6dB of gain at 50Hz
- HF Contour - Smooth shelving filter, +/-6dB of gain at 14kHz
- GAIN - Used for overall unity gain adjustment. Adjustable from - infinity to +10dB
- CLIP - Triple-point clip detector that indicates red when the internal signal is clipping at any one of three critical points
- LED Meter - Shows output signal level (input signal when EQ is bypassed) from -24dBu to +18dBu in 8 steps


  • HP filter set to OUT. GAIN, HF, LF & all faders set to 0
  • Input Section
  • Input Impedance: 10kOhm, electronically balanced
  • Maximum Imput Level : >+20dBu
  • CMRR: >-40dB @1kHz
  • Output section
  • Output Impedance: < 50 Ohms, electronically balanced
  • Maximum Output Level: >+20dBu into 600 Ohms
  • Filters
  • HP filter control: OUT to 250Hz @ 12dB/octave
  • LF contour: +/-6dB shelving @ 50Hz 6dB/octave
  • HF contour: +/-6dB shelving @ 14kHz 6db/octave
  • FREQUENCY bands: +/-15dB on ISO centres with a Q of 4
  • General Performance
  • Frequency Response: 5Hz to 45kHz +/-1dB
  • Noise: <-94dBu 22Hz to 22kHz
  • Dynamic Range: > 115dB
  • Cross Talk: >-80dB @1kHz
  • Distortion: <0.005%THD (80kHz measurement
  • BW) 20Hz-20kHz.
  • GAIN control: +10dB to -infinity
  • Dimensions: 19" x 5.25" x 7.1" (483mm x 134mm x 180mm)
  • Weight: 6.6lbs (3kgs), unpacked
  • AC Power: 115/230V AC, 50/60Hz, 30VA

Q & A

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Shipping Weight
11.50 lbs.
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