HQ 231 EQ

Pro Dual 31 Band EQ w/ FDC™
The HQ231 Dual 31-band Graphic EQ is perfect for any live
sound application where there is a high feedback potential
including monitor mixes, side-fill cabinets or high powered
front-of-house mixes situations.

The HQ231 features ART's proprietary FDC™ (Feedback Detection Circuit),
with constant Q circuitry capable of delivering a 3% center
frequency accuracy. Professional features like LED level metering,
selectable 6dB or 12dB slider range, active balanced and unbalanced
input & output connectors, RFI filters, independent variable Hi Pass
(low cut) and Low Pass (high cut) filters, variable input level control,
passive bypass switch, clip level indicator, ground lift switch, and
selectable line voltage switch make it ideal for any professional
application or touring system.

FDC Feedback Detection Circuit
FDC (Feedback Detection Circuitry - designed and developed by ART Engineering)
instantly illuminates an LED on the corresponding EQ band fader
with the greatest sustained signal. The LED indicators can immediately
show which band corresponds to the feedback frequency, allowing the
sound engineer to reduce gain in that band to quickly kill the feedback
while having a minimal impact on the sound of the live program material.

The FDC also acts as a simple spectrum viewer while the concert proceeds
showing where the "hot" areas are. During system setup and sound check,
the FDC may be used to help identify room and sound system resonances.
By increasing the gain until feedback, it is easy to identify those frequencies
that are likely to be problems. Reducing the gain in these bands helps tune
the sound system, and, remove problem areas before the show begins. It
also helps increase the gain margin before feedback.

Constant-Q Filtering 
The HQ231 features Constant-Q Filtering, which helps the HQ's FDC work with
greater efficiency while offering superior overall performance of the EQ. Constant-Q
ensures that even when making radical adjustments to a frequency band, that
adjacent bands will not be affected. This is particularly critical in professional
applications including monitor mixes and feedback control.

Professional Feature Set
Professional features like 45mm center detent sliders with selectable boost or
cut range of 6dB or 12dB ensures the HQ231 can be used for radical tone shaping,
or precise control of a sound system. Versatile connection to any live sound system
or installation can be easily made using balanced XLR, 1/4-inch TRS and unbalanced
RCA input and output jacks included on the HQ231 back panel.

High and low pass filters, analog level metering, variable input level controls, signal
clip level indicators, ground lift switch, internal power supply and selectable line
voltage complete the HQ231 Dual 31-Band Graphic EQ's full feature set.