QSC GXD 4 Lightweight Profesional Power Amplifier

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.

• 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 and low-pass filters, 4-band parameteric EQ, 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.
• Adjustable speaker protection to match your loudspeaker’s power and impedance.
• Front panel LEDs indicate signal presence, input overload, and amplifier clipping.