RD400/4 4-Channel Amplifier

The JL Audio RD400/4 is a compact, 4-channel Class D full-range mobile amplifier engineered to provide powerful audio output with high efficiency and low distortion. Utilizing the brand's proprietary NexD high-speed switching technology, it delivers 100 watts RMS per channel into 2-ohm loads or 75 watts RMS into 4-ohm loads at 14.4V. The unit is fully bridgeable, allowing for flexible setups including a 200W x 2 configuration at 4 ohms. Installation and configuration are simplified with controls mounted on top of the chassis under a protective cover, while all connections are located on a single side. The amplifier features studio-grade signal processing, including defeatable high- or low-pass 12 dB/octave filters with variable frequency selection from 50-500 Hz. Key features include onboard LED-clipping indicators that allow for accurate input sensitivity setting without specialized equipment. The chassis is finished in a durable black powder coating and includes a top-mounted status LED strip. The unit also offers automatic turn-on capability via signal or DC-offset sensing and provides preamp outputs for daisy-chaining additional amplifiers.