MB Quart RW-108A 8" Powered Under-Seat Subwoofer

The MB Quart RW-108A is a compact powered subwoofer enclosure designed to add low-frequency support where conventional subwoofer boxes will not fit. Its slim under-seat form factor is suited to vehicles with limited cabin or cargo space. The integrated amplifier keeps the installation focused on one enclosure rather than separate subwoofer and amplifier components.

This model uses an 8-inch, 4-ohm subwoofer in a self-contained enclosure and carries a 600-watt maximum-power listing. It is intended for car-audio systems that need more bass presence than factory speakers typically provide. The compact format makes it a practical option for cars, trucks, RVs, and similar vehicle applications when clearance is available.

Signal connection flexibility helps the RW-108A work with a range of source units. It provides RCA low-level inputs for aftermarket receivers with preamp outputs, along with a high-level input for systems using speaker-level signal. A remote turn-on terminal and selectable auto-turn-on function support different installation approaches.

Onboard adjustment controls let the installer tailor the enclosure to the rest of the system. Input-level, bass-boost, and low-pass-filter controls help blend the subwoofer with full-range speakers, while the 0/180-degree phase switch can assist with bass integration. Power and protect indicators provide at-a-glance operating-status feedback.

A wired bass-level remote is included for convenient adjustment from the cabin. This makes it easier to reduce output for everyday listening or raise it when program material calls for more low-end reinforcement. The RW-108A is best used as a compact bass upgrade in a properly fused 12-volt vehicle-audio installation.

Key Features

• 8-Inch Powered Subwoofer: Combines a compact woofer and built-in amplifier.
• Slim Under-Seat Format: Helps conserve usable vehicle cabin and cargo space.
• 600-Watt Maximum Rating: Provides the product's advertised maximum power specification.
• High- And Low-Level Inputs: Supports speaker-level wiring or RCA preamp connections.
• Wired Bass-Level Remote: Lets you adjust subwoofer output from the cabin.
• Adjustable Integration Controls: Includes gain, bass boost, low-pass, and phase settings.

Design & Installation

The RW-108A uses a low-profile black enclosure with an integrated amplifier section and a protective grille over the woofer. Its compact layout places power, signal, remote-control, and adjustment connections together on the enclosure. Power and protect LEDs, an integrated fuse, and accessible tuning controls support routine setup and troubleshooting.

Mount the enclosure securely on a flat surface with adequate ventilation and without obstructing vehicle controls, seat movement, or safety equipment. Connect it to fused 12-volt power, a solid chassis ground, and either RCA or speaker-level signal; use the REM terminal or the auto-turn-on setting as appropriate for the source unit. Set gain conservatively, then use the low-pass filter and phase control to blend bass with the vehicle's main speakers.