QSC CMX800Va 800-Watt Two-Channel Commercial Power Amplifier

  • 800 Watt @4 ohms; 1200 Watt @2 ohms
  • “Flex-Use” loading options allows CMX Series amps to drive low-impedance loads down to 2 ohms
  • “Flex-Use” input connectivity choices including actively balanced barrier strip, XLR, or ¼” TRS
  • Rack mountable with chassis less than 16″ (40.6 mm) deep
  • Tamper-proof security cover for gain controls

$1,112.00 CAD

In stock


About QSC CMX800Va 800-Watt Two-Channel Commercial Power Amplifier

The New CMXa Series is an economical and rugged power amplifier designed to meet the needs of system integrators. It is based upon the proven, rock-solid, reliable performance found in the award winning RMX Series. The CMXa feature sets are designed for wide-ranging application in facilities such as performance halls, houses of worship, sports clubs, gymnasiums, dance venues, pubs, and FGM/BGM systems. The CMXa Series provides unmatched performance, the right power for the job and an affordable price point.

Proven and Reliable Power Plant

CMXa amplifiers incorporate everything QSC has learned in more than forty years of striving to deliver worry-free operations without failures. The design of these amplifiers starts with our world-class power supplies. The CMXa uses a powerful, high-current toroidal transformer and filtering to ensure generous energy reserves. This allows the amplifiers to effortlessly handle high-level transients, even when driving abusive 2 ohm speaker loads.

The amplifier output sections feature rugged class AB and class H architecture depending on power level. Efficient class H output sections on the CMX 800Va and CMX 2000Va reduce AC current draw and cut down on waste heat.

All CMXa amplifiers are protected from damage from shorted outputs. Automatic current limiting protects the amplifier from damage until the short is corrected.

CMXa amplifiers also feature DC protection systems to prevent loudspeaker damage in the unlikely event of an output transistor failure. DC voltage from the power supply is never passed directly to your speakers, even in the event of an output circuit failure.

Superior Performance

The CMXa amplifiers deliver true and accurate studio-quality sound. A full complementary output circuit using high-grade linear output devices generates accurate, flat-frequency response with low distortion. SMT (Surface Mount Technology) triples small-signal component density, enabling high power output in a 2 rack unit chassis (3 RU for the CMX 2000Va). Unlike other designs, CMXa output devices are directly mounted to the heat sink for optimum thermal coupling and cooling.

The CMXa Series is available in four models. Three 2-rackspace models range in power from 300 to 800 watts per channel at 4 ohms. One 3-rackspace model provides 2500 watts per channel at 2 ohms. All four models feature a compact chassis less than 16” deep.

The V in the model name designates the ability to directly drive 70-volt and/or 100-volt distributed loudspeakers. The CMX 300Va and CMX 500Va must be configured for bridgedmono operation in order to directly drive high-impedance systems while the CMX 800Va and 2000Va may be used in either stereo or mono mode.

For installations requiring a transformer isolated output, the CMX has optional accessories to cover your needs.

Additional information

Weight 44.8 lbs
Dimensions 24 x 21.7 x 6 in


QSC CMX800Va 800-Watt Two-Channel Commercial Power Amplifier Features:

  • “Flex-Use” loading options allows CMX Series amps to drive low-impedance loads down to 2 ohms, and certain models can direct-drive (no output transformer) 70V and 100V distributed loudspeaker systems
  • “Flex-Use” input connectivity choices including actively balanced barrier strip, XLR, or ¼” TRS
  • “Flex-Use” output connectivity choices include NL4 Speakon™ and detachable terminal block
  • Rack mountable with chassis less than 16″ (40.6 mm) deep
  • 1-dB recessed, detented gain controls for fast, accurate, and repeatable settings
  • Tamper-proof security cover for gain controls
  • Recessed rear DIP switches for easy selection of stereo, parallel, or bridged mode operation, and enabling/disabling low-frequency filter protection
  • Low-noise variable-speed fans with rear-to-front airflow help keep amplifiers and racks cool


  CMX300Va CMX500Va CMX800Va CMX2000Va
Stereo Mode (both channels driven)

8Ω FTC 0.1% THD
8Ω EIA 0.1% THD
4Ω FTC 0.1% THD
4Ω EIA 0.5% THD

70V Direct EIA 1% THD
100V Direct EIA 1% THD

FTC: 20 Hz–20 kHz after preconditioning
EIA: 1 kHz

185 W
200 W
280 W
300 W
430 W–
260 W
300 W
400 W
500 W
700 W–
450 W
500 W
650 W
800 W
1200 W400 W
1050 W
1100 W
1600 W
2000 W*
2500 W2500 W
1000 W
Bridge Mono Mode
8Ω FTC, 0.1% THD
8Ω EIA, 0.1% THD
4Ω EIA, 1% THD70V Direct Drive EIA, 1% THD
100V Direct Drive EIA, 1% THDFTC: 20 Hz–20 kHz after preconditioning; both channels driven simultaneously
EIA: 1 kHz
530 W
600 W
830 W600 W
800 W
900 W
1400 W1200 W
600 W
1300 W
1500 W
2400 W2000 W
2300 W
3200 W
3600 W
5000W5000 W
3600 W
Signal to Noise (20 Hz–20 kHz, 8Ω) > 100 dB
Input Sensitivity into 8Ω 1.15 V (+3.4 dBu) 1.14 V (+3.4 dBu) 1.23 V (+4.0 dBu) 1.42 V (+5.3 dBu)
Max Voltage Gain 31.6× (30 dB) 40× (32 dB) 46× (33 dB) 64× (36 dB)
Output Circuitry Class AB Class AB 2-tier Class H 3-tier Class H
Current Draw (pink noise program)
Typical, 1/8 power 4Ω, 120 V
Typical, 1/8 power 4Ω, 230 V
Severe, 1/3 power 4Ω, 120 V
Severe, 1/3 power 4Ω, 230 V
4.4 A
2.2 A
6.6 A
3.3 A
5.4 A
2.7 A
9.6 A
4.8 A
6.3 A
3.2 A
15.6 A
7.8 A
13.9 A
7 A
26.9 A
13.5 A
Distortion (SMPTE-IM) < 0.02% < 0.01% < 0.01% < 0.01%
Distortion (typical)
20 Hz–20 kHz: 10 dB below rated power
1.0 kHz and below: full rated power
< 0.03% THD / 4Ω and 8Ω
< 0.03% THD / 4Ω and 8Ω
Frequency Response 20 Hz–20 kHz: ±1 dB; -3 dB points: 5 Hz and 50 kHz
Damping Factor (1 kHz and below) > 300 at 8Ω
Input Impedance 10 kΩ unbalanced, 20 kΩ balanced
Input Clipping 10 V rms (+22 dBu)
Cooling Continuously variable-speed fan, rear-to-front air flow
Connectors (each channel) Input: Active balanced; barrier strip, XLR and ¼” (6.3 mm) – TRS tip and XLR pin 2 positive
Output: Detachable terminal block and Neutrik™ Speakon™
Controls Front: AC switch, Channels 1 & 2 gain knobs
Rear: 10-position DIP switch
Indicators Power-on: Green LED / Signal: Green LED (1 per channel) / Clip: Red LED (1 per channel)
Amplifier Protection Stable into reactive or mismatched loads
Load Protection On/off muting, AC coupling (CMX 300Va and CMX 500Va), triac crowbar (CMX 800Va and CMX 2000Va on each channel)
Power Requirements 120 or 230 VAC, 50 – 60 Hz
Dimensions (HWD)
2 RU models3 RU model (CMX 2000Va)
3.5″ (8.9 cm) 2 rack spaces x 19″ (48.3 cm) rack mounting x 15.9″ (40 cm) deep to rear support ears
5.25″ (13.3 cm) 3 rack spaces x 19″ (48.3 cm) rack mounting x 15.9″ (40 cm) deep to rear support ears
Weight – Net 35 lb (15.9 kg) 40 lb (18.2 kg) 44.5 lb (20.2 kg) 75 lb (33.1 kg)
Weight – Shipping 41 lb (18.6 kg) 46 lb (20.9 kg) 50.5 lb (23 kg) 87 lb (37.2 kg)

* 1% THD


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