HELIX SRC - Subwoofer Remote Control – HARRIOX GROUP
LECMARK Universal Car Audio Controller Sound Adjuster Boost RCA Level Remote Subwoofer Control : Amazon.in: Electronics
AMPIRE universal RCA level control for amplifier or active subwoofer | RCA Controller | Car Audio Electronics
Edge Lcv Universal Bass Knob Level Controller with Built-in Digital Voltmeter, Blue LED Display, Remote Gain Control, on/off Switch, Prevent Damage to Your Au - China Level Controller, Line Output Converter
Amazon.com: XMSJSIY Bass Control Knob Remote Amplifier Replacement Bass Controller Car Audio Adjustable with 6 Pin Extension Cable for Subwoofer-3.8M/12.6FT Cable : Electronics
RBC | Remote Bass Control. Dial in the perfect bass.