JL Audio 280 Watt 4 Channel Bridgeable Class D Full-Range Marine Amplifier (MX2804)

JL Audio NexD™ Switching Technology

NexD™ amplifier technologies produce exceptional audio quality, unsurpassed total efficiency and high power from very compact amplifier designs.

Beginning with the original ‘Slash’ subwoofer amplifiers, JL Audio has been at the forefront of Class D amplifier design. Today, our flagship Single-Cycle Control™ technology sets the ultimate standard for Class D amplifier performance. The NexD™ amplifiers may be a bit less complex, more compact and more affordable, but they flow from the same minds that have set the trend in mobile amplifier technology for over a decade.

Let’s get a little nerdy… A traditional PWM switching amp design uses a fixed switching frequency and varies the pulse width based solely on the audio input signal to the pulse modulator. This basic approach assumes some ideal conditions, like a rock-steady power supply, that do not necessarily occur in a real, in-car installation. Power supply sag with signal causes distortion at all power levels with these designs, even well below clipping. The cure for this is feedback (a corrective signal sent back to the input side), but this becomes impractical as the audio frequency increases, making it a good solution for band-limited (subwoofer) amps, but not for full-range amplifiers.

Taking the above into account when designing the NexD™ subwoofer amplifiers, we have taken the simple fixed PWM approach and enhanced it with a very high switching frequency: 240 kHz, which is about 4x higher than most Class D subwoofer amplifiers. This pushes the amplifier’s bandwidth to at least 500 Hz with minimal distortion and improves efficiency, while keeping typically bulky circuity more compact. Your subwoofers will reward you with tight, rock-solid bass performance.

For the full-range NexD™ amplifiers and channels we applied a variable, ultra-high speed version of the NexD™ technology (switching at well over 400 kHz). In these designs, a self-oscillating modulator with “feed-forward” sends information about the instantaneous power supply voltage to the modulator, combining this with the input signal to cancel out any distortion due to supply voltage fluctuation. This reduces distortion prior to applying feedback, simplifying the overall feedback loop design.

The bottom line is simply great audio: clean, powerful and reliable.

JL Audio 4 Channel Marine Amplifier Highlights:

• 4-Channel Class D Full-Range Amplifier, 70 W x 4 @ 2 Ω / 50 W x 4 @ 4 Ω – 14.4V
• Engineered specifically for powersports applications
• High-speed NexD™ switching design to deliver plenty of clean power, without straining charging systems.
• Tiny cast aluminum chassis is highly resistant to corrosion
• IPX6 water-resistance rating, making it perfect for motorcycles, ATV’s or other utility vehicles.
• Solid 50W x 4 into 4 ohms (14.4V, 1% THD)
• Bridgeable so it can be used as a 3-channel amplifier, or as a 2-channel amplifier producing a potent 140W x 2 into 4 ohms.
• Independent front and rear crossovers with selectable full-range, high-pass or low-pass filter controls
• Dual-range input section that accepts a wide range of input voltage levels
• Line-level all the way to high-power speaker level signals
• Black powder-coated finish with a gasket cover for the controls and stainless steel hardware for durability