Mackie SR18S 18" 1600W Powered Professional Subwoofer

The Mackie SR18S is an 18-inch powered professional subwoofer for PA systems that need dedicated low-frequency reinforcement. Its built-in Class-D amplifier and integrated processing eliminate the need for a separate subwoofer power amp. It is suited to working musicians, DJs, venues, event setups, and other portable sound applications.

With selectable Flat, Deep, and Punch voicing modes, the SR18S lets users tailor its low-frequency character to the program material and system goal. Flat provides balanced bass response, Deep extends the lowest frequencies, and Punch prioritizes output. Its maximum peak SPL is rated at 133 dB.

The SR18S uses an 18-inch ferrite woofer in a rectangular 15 mm poplar plywood enclosure. Frequency response varies by selected high-pass mode, reaching 33 Hz to 200 Hz at -10 dB in Deep mode. The system is designed to handle bass duties so connected full-range loudspeakers can focus on higher frequencies.

Two balanced XLR inputs accept stereo left and right line-level signals, while dedicated high-pass outputs can feed powered top speakers. Full-range XLR outputs support additional powered subwoofers or other loudspeakers, with selectable separate or mono-summed output operation. A variable high-pass mode adjusts from 80 Hz to 160 Hz when used with non-SRT top speakers.

For Mackie SRT-series top speakers, the SR Flat, SR Deep, and SR Punch modes provide coordinated processing for the subwoofer and connected loudspeakers. A normal/invert polarity switch helps optimize the blend between the subwoofer and tops in different placements. Built-in peak and RMS limiting, thermal protection, and a universal switchmode power supply support practical event use.

Key Features

• 18-Inch Ferrite Woofer: Provides dedicated low-frequency reproduction for PA systems.
• 1600W Peak Class-D Amplifier: Powers the subwoofer without an external amplifier.
• Custom Voicing Modes: Flat, Deep, and Punch modes adapt bass response to the application.
• Variable High-Pass Mode: Adjusts the crossover point from 80 Hz to 160 Hz.
• Flexible XLR Connectivity: Includes stereo inputs plus full-range and high-pass outputs.
• System Protection: Peak/RMS limiting and thermal protection help monitor demanding operation.

Design & Installation

The SR18S is built in a rectangular 15 mm poplar plywood cabinet with a black polyurethane finish. Its front grille is made from 11-gauge ASTM A36 steel with a black powder-coated finish, and one handle on each side supports transport. A defeatable front power LED and rear-panel high-pass-mode and signal/clip indicators provide simple status visibility.

Place the SR18S on a stable floor or stage surface; it is not designed to be suspended or mounted on a pole. Connect a mixer or other line-level source to the balanced XLR inputs, then route the high-pass outputs to powered top speakers when desired. The top socket may be used to support a loudspeaker with a compatible pole; allow at least six inches of free space behind the subwoofer for ventilation.