RD400/4
4-Channel Class D Full-Range Amplifier, 100 W x 4 @ 2 Ω / 75 W x 4 @ 4 Ω - 14.4V
Utilizing our exclusive NexD™ high-speed switching technologies, the ultra-compact RD400/4 amplifier is engineered to deliver loads of audio output power, with incredible efficiency and low distortion. Don’t let its modern styling and small size fool you though, this little powerhouse churns out 100 watts of crystal-clear audio from each of its four channels into 2 ohms (14.4V, 1% THD) and is fully bridgeable, so it can be used as a 3-channel amplifier, or as a 2-channel amplifier producing a whopping 200W x 2 into 4 ohms.
For your convenience, the RD400/4’s controls can be found on top of the amplifier, beneath a protective cover, with all connections located along one side of its chassis. Studio-grade signal processing features include high or low-pass 12 dB / octave filters (defeatable) for each channel pair, with continuously variable frequency selection from 50-500 Hz, and dual-range, differential-balanced inputs capable of accepting most input voltage levels. Automatic turn-on capability (via signal sensing or DC-offset sensing) is standard equipment, along with all-new input type switches for bridging of stereo output channels without needing to use Y-adaptors.
Onboard LED-clipping indicators are also included with your RD400/4. This all-new, innovative feature lets you easily set your amplifier’s input sensitivity settings, quickly and accurately, with no special equipment needed. You’ll also find a set of preamp outputs on-hand, so you can pass signals to another amplifier, almost effortlessly. The RD400/4 features a durable, black powder-coated finish and a top-mounted, dual-color LED light strip that reports the overall status and condition.
Rated Continuous (RMS) Power @ 14.4 V
@ 4 Ω | 75 W RMS x 4 |
@ 3 Ω | 100 W RMS x 4 |
Bridged @ 4Ω | 200 W RMS x 2 |
Rated Continuous (RMS) Power @ 12.5 V
@ 4 Ω | 60 W RMS x 4 |
@ 3 Ω | 90 W RMS x 4 |
Bridged @ 4Ω | 180 W RMS x 2 |
General Specifications
Frequency Response | 12 Hz - 22 kHz (+0, -1dB) |
S/N Ratio, referred to highest rated power | >104 dB below rated power (A-weighted, 20 Hz - 20 kHz noise bandwidth) |
S/N Ratio, referred to 1 W | >84 dB (A-weighted, 20 Hz - 20 kHz noise bandwidth) |
Damping Factor @ 4 Ω | >150 / 50 Hz |
Damping Factor @ 2 Ω | >75 / 50 Hz |
THD+N @ Rated Power | <1% @ 2 Ω per Ch. |
Input Voltage Range @ RCA Inputs | Switchable from 200 mV - 2 V RMS (Low) to 800 mV - 8 V RMS (High) |
Min.Copper Power / Ground Wire Gauge | 4 AWG wire |
Fuse Rating | 40 A (AFS, AGU or MaxiFuse™) |
Signal Processing
Filter Mode(s) | Low-Pass or High-Pass |
Filter Slope(s) | 12 dB/octave |
Filter Frequency Range | 50 Hz - 500 Hz |
Detented, Calibrated Filter Freq. Potentiometers | No |
Filter Defeat Function | Yes |
Remote Level Control | No |
Remote Level Modes | N/A |
Channel Input Mode Switch | Yes (2/4 ch.) |
Pass-Through Preamp Output | Buffered |
Source Channel Selection for PreOuts | No |
Physical Specifications

JL Audio Warranty
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Number Of Channels: |
4 Channel |
UPC: |
699440986212 |
RMS Power In Watts: |
251-500 Watts |
Bundle: |
No |
Feature 1: |
Developed in-house by the same engineering team that brought you the XDv2 and HD amplifiers, our latest RD amplifiers utilize JL Audio’s exclusive NexD™ switching technologies to generate loads of power with exceptional efficiency to reduce current d |
Feature 2: |
Developed in-house by the same engineering team that brought you the XDv2 and HD amplifiers, our latest RD amplifiers utilize JL Audio’s exclusive NexD™ switching technologies to generate loads of power with exceptional efficiency to reduce current d |
Feature 3: |
Just like the XDv2 amplifiers, RD amps are equipped with studio-grade signal processing and automatic turn-on capabilities |
Feature 4: |
Differential-balanced inputs are also on-hand to combat noise and maximize compatibility with a wide range of signal types. |
Feature 5: |
Two brand new features have been added to simplify installation and set-up: easy-to-use LED clipping indicators |
Condition: |
NEW |
Manufacturer SKU: |
98621 |
Weight: |
8 lbs |
1 Review Hide Reviews Show Reviews
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Awesome
Received My Product As Described, Got A Full System Connected Mids & Highs With A 13.5 JL Audio Subwoofer & JL Audio Class-D Monoblock RD1000 Amp As Well. Everything Sounds On Point A+