QSC Audio RMX 4050HD Professional Power Amplifier Dual Monaural Supply - Tested

Comes with unit only, some surface scuffs that are cosmetic in nature. Condition is tested and working, pulled from a working environment. Shipped USPS for FREE the very same day you order to make sure you get it FAST. If you have any issues with this item at all please just me a message immediately, before leaving feedback, and I promise to solve it whether that means a full refund or a replacement. Whatever the case, I’m here to make sure your experience ordering from me goes well.

If you have any issues with this item at all please just me a message immediately, before leaving feedback, and I promise to solve it whether that means a full refund or a replacement. Whatever the case, I’m here to make sure your experience ordering from me goes well.

The QSC RMX 4050HD is a professional 2-channel (stereo) power amplifier from QSC’s RMX Series, designed for high-power sound reinforcement applications such as professional touring, performing musicians, mobile DJs/entertainers, and installed systems. 

It is a “Heavy Duty” (HD) model optimized for demanding 2-ohm stereo or 4-ohm bridged loads, with improved thermal performance compared to standard RMX models. It uses a three-tier Class H topology for high efficiency at real-world power levels, reducing wasted AC current while delivering sustained output. The 120V version operates on a standard 15-amp plug. It features a compact 3RU chassis (under 16” deep), dual-mono high-current power supply for reliability, and road-proven QSC design elements. 

Key Features

• High continuous power into low impedances, with robust performance in 2Ω stereo and 4Ω bridged modes.

• Dual mono, high-current power supply for better reliability and performance.

• User-defeatable clip limiters (independent per channel) to reduce distortion.

• Selectable low-frequency filters (30 Hz or 50 Hz, 12 dB/octave, independent per channel) to protect speakers and increase headroom.

• Balanced inputs: XLR, 1/4” TRS, and barrier strip screw terminals per channel.

• Outputs: Touch-proof binding posts and Neutrik Speakon® (Channel 1 Speakon supports bi-amp/stereo wiring).

• Front-panel gain controls, with Signal (yellow, -30 dB), Clip (red), and Protect (red) LEDs per channel, plus Power-on (green) LED.

• Protection: Independent DC/thermal overload per channel, short/open circuit, ultrasonic/RF protection, turn-on/off muting, stable into reactive/mismatched loads. Triac crowbar load protection.

• Cooling: Continuously variable-speed fan with rear-to-front airflow.

• Mode selection (via rear DIP switches): Stereo, Parallel, or Bridge Mono.

• Other: Front AC power switch, rear push-button circuit breakers per channel (or equivalent), IEC power inlet, 3-year warranty (optional extended service).