The Sinister SDX4 is part of Wet Sounds’ premium Sinister Series amplifier range — a 4-channel, full-range Class-D amplifier built around Wet Sounds’ patented MAXED™ power supply technology for a level of efficiency that sets it apart from standard marine amplifiers. If you’re building a high-output system and want to minimise the strain on your boat’s electrical system without sacrificing performance, the SDX4 delivers exactly that.

The MAXED™ power supply is a patented Wet Sounds technology designed to achieve efficiency levels previously considered unattainable in a mobile audio amplifier — less current draw, less heat generated, and less strain on your boat’s charging and battery system, meaning more play time on the water. Class-D topology further enhances this efficiency, while layered PCBs and advanced microprocessors keep the design compact and reliable in the harshest marine environments.

Four channels of full-range output deliver 185W per channel at 4Ω stereo, 340W per channel at 2Ω stereo, or 685W per channel bridged to mono at 4Ω across two channels — giving you the flexibility to power tower speakers, cabin speakers, or subwoofers from a single amplifier. The crossover is adjustable from 30Hz to 300Hz at 12dB per octave for both high and low pass configurations, with a bass boost of 0–12.5dB adjustable between 27Hz and 110Hz for subwoofer tuning. Overvoltage protection kicks in at 15.6V to protect your system, and the remote level control adjusts from 0dB to -61dB for precise volume management.

All Sinister Series amplifiers share a single full cast aluminium chassis size across the range, making installation straightforward and the finished result clean. Removable speaker plugs, high-level speaker input, and an LED-badged enclosure complete the package. Backed by Wet Sounds’ 2-year limited warranty.

Specifications

• Channels: 4
• Amplifier class: Full-range Class-D
• RMS power @ 4Ω stereo: 185W × 4
• RMS power @ 2Ω stereo: 340W × 4
• RMS power @ 4Ω mono bridged: 685W × 2
• Frequency response: 8Hz – 35kHz (-3dB)
• Signal-to-noise ratio: >90dB / >113dB (A-weighted)
• Input sensitivity: 0.2V – 6.1V (low level)
• Crossover range: 30Hz – 300Hz, 12dB/octave (high and low pass)
• Bass boost: 0 – 12.5dB @ 27Hz – 110Hz
• Remote level range: 0dB to -61dB
• Over voltage protection: 15.6V
• Power supply: MAXED™ patented technology
• Chassis: Full cast aluminium