The EQ231-GSP is a highly versatile combination of dual 31 band 1/3 Octave
Graphic Equaliser, LF and HF variable frequency Shelving Equaliser, variable
High and Low Pass filters and Limiter-Noise Gate.
The band pass filters are based around precision minimum phase active RC
networks to deliver superior dynamic range and signal to noise performance.
An optional Inductor board may be specified for the top eight frequencies (4kHz-20kHz)
to further improve noise and phase linearity. Long throw faders provide maximum
sensitivity and control of 12dB cut and boost at 31 ISO centre frequencies covering
the entire audio spectrum (20Hz to 20kHz).
The Shelving Equaliser section offers continuous adjustment of boost/cut and
corner frequency. This allows an engineer to tailor the sound without altering the
graphics settings. The High and Low Pass filters use 4th order bi- quadratic topology
to offer 24dB/octave slope and superior stability. The Dynamics section uses a fast
RMS detector with soft-knee characteristics. The Limiter features a Threshold control
and 3-segment gain reduction display. The Noise Gate features a Threshold Control
and Gate Closed indicator.
The EQ231-GSP has electronically balanced inputs and outputs on XLR, with front
panel phase reverse switches on the outputs. An optional Transformer Output module
is available, featuring Active Distortion Cancellation circuitry that reduces to negligible
levels the LF distortion inherent in Passive Transformer designs. Power relays ensure
silent power on/off and also automatic bypassing of the unit when switched off. All
switches are indicated with status LED’s. Each channel incorporates an input level
control with clip LED and may be individually bypassed.
The EQ231-GSP is built in accordance with Electro-Magnetic Compatibility (EMC)
regulations encompassed within the European ”CE’ mark. This guarantees problem
free integration into audio systems.
Dual 31 band 1/3 octave Graphic Equaliser
LF and HF Variable Frequency Shelving Equaliser
Variable Low and High Pass filters
Gate and Limiter Dynamics section
Relay based ‘soft’ power up and automatic power off bypass
Input level control with Peak LED
Channel bypass switches with LED
Output Transformer option with unique Active Distortion Cancellation circuitry
Inductor option for improved noise and phase response on high frequencies
Frequency Response 20 Hz – 20 kHz, -1dB
Signal to Noise Ratio @ +4dBu output -96dB
Input impedance 20 kΩ balanced
Output impedance 100Ω balanced
Maximum Output Level
(into 600Ω Load, 1 kHz, 600 Ohms Load)
Total Harmonic Distortion
(1kHz, +4dBu Output)
Peak indicator Threshold 2dB before clipping
Centre frequencies :
20, 25, 31.5, 40, 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800, 1k,
1k25, 1k6, 2k, 2k5, 3k15, 4k, 5k, 6k3, 8k, 10k, 12k5, 16k, 20k.
Limiter Threshold -6 to +20dBu
Gate Threshold -70 to -20dBu
Limiter Ratio 20:1 soft-knee
Gate Ratio 10:1 soft-knee
Hi-Pass Filter corner frequency 16Hz to 160Hz
Hi-Pass Filter slope 24dB/Octave Butterworth
Lo-Pass Filter corner frequency 3KHz to 32KHz
Lo-Pass Filter slope 12dB/Octave Butterworth
LF Shelving EQ Frequency 16Hz to 160Hz
HF Shelving EQ Frequency 2.5KHz to 25KHz
(115/220 VAC, 50-60 Hz)
Weight 7.2 kg
Dimensions (mm) 483 W x 230 D x 135 H
Note: 0dBu is referenced to 0.775 V RMS.