RMX 850aRMX 1450aRMX 2450aRMX 4050aRMX 5050a
Power per Channel, Stereo Mode (both channels driven)
8Ω, FTC 20 Hz?20 kHz, 0.1% THD 185 W 260 W 450 W 800 (650**) W 1050 W
8Ω, EIA 1 kHz, 0.1% THD 200 W 300 W 500 W 850 W 1100 W
4Ω, FTC 20 Hz?20 kHz, 0.1% THD 280 W 400 W 650 W 1300 W 1600 W
4Ω, EIA 1 kHz, 0.1% THD 300 W 500 W (0.5% THD) 750 W 1400 W 1800 W
2Ω, FTC 20 Hz?20 kHz, 1% THD ? ? ? 1600 W 2000 W
2Ω, EIA 1 kHz, 1% THD 430 W 700 W 1200 W 2000 W 2500 W
Power, Bridge-Mono Mode
8Ω, FTC 20 Hz?20 kHz, 0.1% THD 530 W 800 W 1300 W 2600 W 3200 W
8Ω, EIA 1 kHz, 0.1% THD 600 W 900 W 1500 W 2800 W 3600 W
4Ω, EIA 1 kHz, 1% THD 830 W 1400 W 2400 W 4000 W 5000 W
Signal to Noise (20 Hz?20 kHz) -100 dB -100 dB -100 dB -100 dB -100 dB
Distortion (SMPTE-IM) < 0.01% < 0.01% < 0.02% < 0.02% < 0.02%
Input Sensitivity at 8Ω 1.15V (+3.4dBu) 1.15V (+3.4 dBu) 1.23V (+4.0 dBu) 1.42V (+5.3 dBu) 1.42V (+5.3 dBu)
Voltage Gain 31.6x (30 dB) 40x (32 dB) 50x (34 dB) 64x (36 dB) 64x (36 dB)
Output Circuitry Class AB Class AB 2-tier Class H 3-tier Class H 3-tier Class H
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
6.0 A
9.6 A
6.3 A
15.6 A
10.0 A
20.1 A
13.9 A
26.9 A
AC Mains Plug
 100/120V
 230V
NEMA 5-15
CEE7/7
NEMA 5-15
CEE7/7
NEMA 5-15
CEE7/7
NEMA 5-15
CEE7/7
NEMA 5-20
CEE7/7
Weight
 Net
 Shipping 
35 lb (15.9 kg)
41 lb (18.6 kg) 
40 lb (18.2 kg)
46 lb (20.9 kg) 
44.5 lb (20.2 kg)
50.5 lb (23 kg) 
68 lb (30.8 kg)
77 lb (34.9 kg) 
75 lb (33.1 kg)
87 lb (37.2 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
< 0.02% THD, 4Ω and 8Ω
< 0.02% THD, 4Ω and 8Ω
Frequency Response 20 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 > 250 at 8Ω
Input Impedance 10 kΩ unbalanced; 20 kΩ balanced
Input Stage Clipping 10 V rms (+22 dBu) 6.4 V rms (+18 dBu)
Cooling Continuously 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® 
Controls Front: AC switch; Channel 1 & 2 gain knobs
Rear: 10-position DIP switch 
LED Indicators Power on: Green; Signal: Yellow (1 per channel); Clip/Protect: Red (1 per channel)
Amplifier Protection Full short circuit, open circuit, thermal, ultrasonic, RF protection. Stable into reactive or mismatched loads
Load Protection Turn-on/off muting; AC coupling (850, 1450); Triac crowbar (1850HD, 2450, 4050HD, 5050) on each channel
Dimensions 3.5” (8.9 cm) tall; 2 rack spaces 5.25” (13.3 cm) tall; 3 rack spaces
Power Requirements 100, 120, 230 V AC (factory configured), 50?60 Hz