Function and setup - This controller sits inline between a car stereo and a secondary amplifier. Connect the car stereo output to the device input, and connect the device output to the amplifier input. Turn the knob to adjust the frequency response and alter the sound. Key benefits - Simple inline solution for volume control and sound shaping of a secondary amplifier. - Allows tonal adjustments without changing the main head unit or primary settings. - Knob provides smooth, repeatable control for comfortable operation. Compatibility and performance - Compatible with car stereo outputs and amplifiers in a vehicle audio system. - Designed to enable frequency-based sound changes, giving you different listening options from the same source. Use scenarios - In-car audio with a second amplifier: fine-tune bass, mids, and highs for different music genres. - Car audio setups requiring quick tonal adjustments: adjust the sound character when switching between songs or genres. - Hobby or testing environments: experiment with frequency-based sound changes by inserting the controller between a source and an amplifier.