QSC RMX 850a Two-Channel Power Amplifier



Item Backordered

Questions? Call 1-800-355-7746 or Chat below

Free Shipping
Best Price + Plus
Check In-Store Availability

Free Shipping on most orders with minimum purchase of $50 or more for a limited time.

Ground shipments only in the lower 48 contiguous United States.

Excludes oversized or overweight items such as oversized speakers, oversized cases, trussing and staging. Other exclusions include some fluids, some parts and special orders.

Any questions, please call 1-800-355-7746 during normal business hours.

Offer subject to change or termination without notice. Not responsible for typographical errors.

The lowest price is not always the best price. When you shop with us, you can always expect to get our BestPrice+Plus guaranteed.

Learn More

1 800 355 7746


I DJ NOW - Babylon, NY store (Pick Up In Store Only)
Mon - Sat 10am - 8pm
Sun 11am - 5:00pm
631 321 1700


I DJ NOW - Queens, NY Store (Pick Up In Store Only)
Mon - Fri 10am - 9pm
Sat 10am - 7pm
Sun 12 noon - 6pm
718 762 0100

The RMXa Series amplifiers offer true professional-quality performance at an affordable price. With 300 watts per channel into 4 ohms and 430 into 2 ohms, all in a chassis that is less than 16" deep, the RMX850a is perfectly suited for performing musicians and mobile entertainers.

QSC RMX850a Two Channel Power Amplifier Features:

  • Compact 2 rack space size.
  • Up to 860 watts in bridge-mono & 430 watts in stereo mode.
  • Professional quality performance - incorporates road-proven QSC designs.
  • High-current toroidal transformers for greater two-ohm power and low noise.
  • Independent user-defeatable clip limiters reduce distortion.
  • Selectable low-frequency filters (30 Hz or 50 Hz) protect speakers and increase headroom.
  • Balanced 1/4" (6.3mm) TRS, XLR and barrier strip inputs.
  • Binding post and Neutrik Speakon outputs.
  • Front mounted gain controls for easy access.
  • Signal and Clip LED indicators to monitor performance
  • Independent DC and thermal overload protection on each channel automatically protects amplifier and speakers.
  • 3-year warranty plus optional 3-year extended service contract.

QSC RMX 850a Specifications
 RMX 850a
Power per Channel, Stereo Mode (both channels driven)
8Ω, FTC 20 Hz–20 kHz, 0.1% THD185 W
8Ω, EIA 1 kHz, 0.1% THD200 W
4Ω, FTC 20 Hz–20 kHz, 0.1% THD280 W
4Ω, EIA 1 kHz, 0.1% THD300 W
2Ω, FTC 20 Hz–20 kHz, 1% THD
2Ω, EIA 1 kHz, 1% THD430 W
Power, Bridge-Mono Mode
8Ω, FTC 20 Hz–20 kHz, 0.1% THD530 W
8Ω, EIA 1 kHz, 0.1% THD600 W
4Ω, EIA 1 kHz, 1% THD830 W
Signal to Noise (20 Hz–20 kHz)-100 dB
Distortion (SMPTE-IM)< 0.01%
Input Sensitivity at 8Ω1.15V (+3.4dBu)
Voltage Gain31.6x (30 dB)
Output CircuitryClass AB
Current Draw (120 V AC)
Typical, 1/8 power pink noise at 4Ω*
Severe, 1/3 power pink noise at 4Ω*

4.5 A
6.6 A
AC Mains Plug

NEMA 5-15

35 lb (15.9 kg)
41 lb (18.6 kg) 
Distortion (typical)
 20 Hz–20 kHz, 10 dB below rated power
 1 kHz and below, full rated power

< 0.03% THD, 4Ω and 8Ω
< 0.03% THD, 4Ω and 8Ω
Frequency Response20 Hz–20 kHz: +0/-1 dB -3 dB points: 5 Hz and 50 kHz (LF filter bybassed, 8Ω)
Damping Factor (1 kHz and below)> 300 at 8Ω
Input Impedance10 kΩ unbalanced; 20 kΩ balanced
Input Stage Clipping10 V rms (+22 dBu)
CoolingContinuously variable speed fan, back-to-front air flow
Connectors (each channel)Input: Active balanced; 3-pin Euro-style detachable terminal block and XLR (pin 2+)
Output: Touch-proof binding posts; Neutrik Speakon® 
ControlsFront: AC switch; Channel 1 & 2 gain knobs
Rear: 10-position DIP switch 
LED IndicatorsPower on: Green; Signal: Yellow (1 per channel); Clip/Protect: Red (1 per channel)
Amplifier ProtectionFull short circuit, open circuit, thermal, ultrasonic, RF protection. Stable into reactive or mismatched loads
Load ProtectionTurn-on/off muting; AC coupling (850, 1450); Triac crowbar (1850HD, 2450, 4050HD, 5050) on each channel
Dimensions3.5” (8.9 cm) tall; 2 rack spaces
Power Requirements100, 120, 230 V AC (factory configured), 50–60 Hz

The RMX 850a Box Includes:

(1) QSC RMX 850a Amplifier
(1) Quick Start Guide
(1) Adhesive Rubber Feet Kit (For non rack-mount applications)
(1) Rear Rack Ear Mounting Kit
(1) IEC Detachable Power Cord

Ratings & Reviews

Be the first to review this product

© 2023 I DJ NOW. All Rights Reserved. Any use of this material including all content, images and design, without prior written consent from IDJNOW, is strictly prohibited by law.