QSC RMX850a Professional Power Amplifier – 830W, Class AB, High-Efficiency Performance for Live Sound & PA Systems
Product Overview
The QSC RMX850a is a high-performance Class AB power amplifier, designed for live sound reinforcement, PA systems, and commercial audio applications. Delivering 300W per channel at 4Ω and 200W per channel at 8Ω, the RMX850a ensures clean, reliable power for speakers in the 300W program range.
Featuring high-current toroidal transformers, the RMX850a provides low noise operation and consistent power delivery, even under demanding conditions. Selectable low-frequency filters (30Hz & 50Hz) protect speakers while increasing headroom, and user-defeatable clip limiters reduce distortion for optimal sound clarity.
Key Features
- Class AB Amplification – Ensures high-fidelity audio performance.
- Power Output: 300W per channel (4Ω), 200W per channel (8Ω), 830W bridged mono (4Ω).
- High-Current Toroidal Transformers – Provides low noise and stable power delivery.
- Selectable Low-Frequency Filters (30Hz & 50Hz) – Protects speakers and increases headroom.
- User-Defeatable Clip Limiters – Reduces distortion for cleaner audio output.
- Front Panel LED Indicators – Displays power, signal presence, and clipping status.
- Parallel XLR & 1/4-inch TRS Inputs – Ensures broad compatibility with various audio sources.
- Speakon® & Binding Post Outputs – Supports secure speaker connections.
- Compact 2U Rack Size – Fits standard rack enclosures.
Technical Specifications
| Specification | Details |
|---|---|
| Power Output (8Ω, continuous, both channels driven) | 200W per channel |
| Power Output (4Ω, continuous, both channels driven) | 300W per channel |
| Power Output (Bridged Mono, 4Ω, continuous) | 830W |
| Distortion (1kHz at full rated power) | <0.02% THD (8Ω), <0.05% THD (4Ω) |
| Signal-to-Noise Ratio (A-weighted, 20Hz–20kHz) | 100 dB |
| Input Sensitivity | 1.15V (+3.4 dBu) |
| Voltage Gain | 31.6x (30 dB) |
| Output Circuitry | Class AB |
| Power Requirements (1/8 power at 4Ω, 120V) | 4.5A |
| Frequency Response (20Hz–20kHz) | +0, -1 dB |
| Dynamic Headroom (4Ω) | 2 dB |
| Input Impedance | >20kΩ (balanced) |
| Maximum Input Level | +24 dBu |
| Input Connectors (Each Channel) | 3-pin XLR, 1/4-inch TRS, RCA (phono) |
| Output Connectors (Each Channel) | Speakon®, 1/4-inch TS, Binding posts |
| Amplifier & Load Protection | Short circuit, open circuit, thermal, RF protection |
| Front Panel Controls & Indicators | Gain controls, signal LEDs, clip LEDs, power LED |
| Rear Panel Controls | Full-range/crossover switch (100Hz, 3rd order LP, 2nd order HP) |
Box Dimensions & Weight
- Dimensions: 3.5" H x 19" W x 10.1" D (standard rack-compatible)
- Weight: 27 lbs
Ideal Applications
- Live Sound Systems
- Professional PA Installations
- Commercial Audio Setups
