Bass boost gives you more control over how your music sounds. It lets you set the optimal bass level for each speaker/sub connected to the GM-D7400M, so the tone controls from your head unit can do what they do best. And because this is selectable bass boost, you can set the level at 0dB, 6dB, or 12dB, whichever sounds best to you.

Pioneer GM GM-D7400M Car Amplifier, 800 W PMPO, 1 Channel, Class D Turn the stereo system around a power pack deck by having 1 x speaker channels While compact sized, Class D offers supreme power with improved audio throughput