QSC GXD4 Datasheet

GXD Series

GXD 4 | GXD 8

Professional Power
Amplifiers

GXD 4 | GXD 8

Features

• High peak output power with up
to 1600 Watts from the GXD 4 and
a whopping 4500 Watts from the
GXD 8.

• Power levels matched to the
most popular loudspeakers and
optimized for maximum real-world
headroom into 4Ω and 8Ω speaker
systems.

• Class-D output stage with a
universal power supply for high
performance and efficiency.

• Extensive and powerful loudspeaker
processing built in. Includes High
& Low-Pass filters, 4-band PEQ,
Limiting, and Delay.

• Large LCD display simplifies
amplifier setup and indicates amp
status.

• Inputs: Parallel XLR and 1/4”
TRS connectors for compatibility
with any source while providing
convenient loop-thru capability.

• Precision rotary encoders for gain
and DSP parameter control.

• Outputs: Professional binding post
and NL4 connectors (compatible
with NL2) provide for mono and
bi-amp speaker connections.

• Digital Limiting automatically
protects the amplifier from
damage due to temperature rise or
overdrive.

GXD Series amplifiers are ideal for
entertainment and production applications
requiring performance and the convenience
of integral signal processing. The hallmarks of
the QSC brand – professional audio quality,
engineering and manufacturing focused on
long-term reliability - are all intrinsic to GXD.
Add contemporary styling, multiple routing
options, light weight, digital signal processing
and advanced protection circuitry, and the GXD
Series clearly represents real value – something
everyone can use.

The GXD series is optimized for use with 8
and 4 ohm loudspeaker loads. GXD amplifiers
deliver just the right amount of power to the
most popular speakers used by entertainers
and production professionals.

The Right Power

There’s a GXD amplifier within 1dB of the ideal
power for your speaker system.

Best practice is to use an amplifier capable of
delivering approximately twice the loudspeaker’s
rated power capacity. Too little amplifier and
the speakers won’t deliver everything they’re
capable of and the risk of destructive amplifier
clipping is increased. Too much power probably
means unnecessary amplifier expense.

To determine the power points for the GXD
series, QSC examined the loudspeakers most
widely used for sound reinforcement by
musicians, DJs and production professionals.
Overall, these speakers are equipped with
woofers that fall into a couple of categories of
continuous power capacity - low-power drivers
that can handle 150 - 250 watts, and mid to
high-power drivers rated around 250-400 watts.
Single woofer loudspeaker systems using these

drivers will typically have an impedance of 8Ω.
Dual woofer loudspeakers will, of course, have
power ratings that are two times that of the
single woofer model and an impedance that is
half that of single-woofer models.

Digital Signal Processing

The GXD amplifiers are unlike other amps
in this category that provide little more than
a front panel screen to control the same
functions that have been under rear-panel,
DIP switch control for decades. The GXD amps
bring full-function loudspeaker processing
capability to a new price point with all the
processing necessary to get the most from a
loudspeaker system. The DSP section includes
High and Low-Pass filters (24dB LR), 4-band
parametric equalizer, signal alignment delay,
and RMS/Peak speaker protection limiting.
Twenty presets for selected typical systems
are provided as generic “starting points” are
included.

Digital Limiting

The most common cause of loudspeaker
failure is amplifier clipping. The digital limiter
used in the GXD amplifiers is set to prevent
the amplifier from being driven into clipping
while delivering the maximum usable
output. In addition to amplifier limiting it also
provides smart speaker protection by simply
setting the loudspeaker’s continuous power

and impedance (4Ω and 8Ω), and selecting
whether Mild, Medium or Agressive protection
is desired.

• Adjustable speaker protection to
match your loudspeaker’s power
and impedance.

• Front panel LEDs indicate signal
presence, input overload, and
amplifier clipping.

Model 8Ω Power /Channel 4Ω Power /Channel Max Total Peak Power

GXD 4 400 Watts 600 Watts 1600 Watts

GXD 8 800 Watts 1200 Watts 4500 Watts

GXD Details

GXD 4 GXD 8

Stereo Mode - Watts per channel

8Ω dynamic, both channels driven

4Ω dynamic, both channels driven

8Ω continuous, both channels driven

4Ω continuous, both channels driven

Distortion (typical)

1 kHz at full rated power < 1% THD

Signal to Noise (A-weighted, 20 Hz – 20 kHz) 100 dB

Input Sensitivity 1.2 Vrms, 3.9 Vrms

Voltage Gain (8Ω) 33.5 dB 36.5 dB

Output Circuitry Class D Class D

Power Requirements: 1/8 power at 4Ω

- 100 Vac

- 120 Vac

- 230 Vac

Frequency Response (20 Hz – 20 kHz) +0.7 dB, -0.8 dB

Dynamic Headroom (4Ω) 1.25 dB 2.73 dB

Damping Factor 100

Input Impedance (Ω) 20k (balanced), 10k (unbalanced)

Maximum Input Level +23.5 dBu

Input Connectors (each channel) 3-pin XLR/F / 1/4" TRS, balanced

Output Connectors (each channel) NL4 (Channel 1 - 1+/-, Channel 2 - 2+/-), binding posts

Amplifier and Load Protection Short circuit, open circuit, thermal, RF protection

Front Panel Controls and Indicators 2 x Rotary Encoders

DSP Functions High Pass Filter, 4th order LR, adjustable Frequency 20 Hz to 4 kHz

Dimensions (HWD) 3.5" (2 RU) x 19" x 10.2" (89 mm x 483 mm x 259 mm)

Weight - Net 11.3 lb (5.1 kg) 13.2 lb (6.0 kg)

Weight - Shipping 15.4 lb (7.0 kg) 17.3 lb (7.8 kg)

Agency Approvals UL, CE, RoHS/WEEE compliant

Carton and Contents Power cable, and quick start guide

600 Watts

800 Watts

400 Watts

600 Watts

3.4 Amps

2.9 Amps

1.6 Amps

Load protected against DC faults

3 x Operational buttons (HOME, ENTER, EXIT)

2 x Green Signal LEDs, indicate signal presence

2 x Red A/D Clip LEDs, indicate input over-drive and/or amplifier current clipping

Blue Power LED ring, AC on

2.12" x 1.0", 256 x 128 pixel LCD

Low Pass Filter, 4th order LR, adjustable Frequency 60 Hz to 4 kHz

4-band PEQ, with variable Frequency, Gain, and Bandwidth

Peak Limiter, with Power, Agressiveness, and Impedance selection

Delay 50 msec max.

1500 Watts

2250 Watts

800 Watts

1200 Watts

6.2 Amps

5.6 Amps

3.2 Amps

Specifications subject to change without notice.

1675 MacArthur Boulevard • Costa Mesa, CA 92626 • Ph: 800/854-4079 or 714/957-7100 • Fax: [phone]

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GXD Spec Sheet 09/25/2014