The sound of the speaker always depends on the room where it is located.
The volume of the active subwoofer can be controlled so that you can adapt the relationship between the active bass and treble / mid-tones to suit the room.
Use your own senses to judge which settings sound best in your room. This switch is especially useful in stereo mode. On the other hand, multichannel amplifiers often have technologies that adjust the subwoofer volume - so when using a multichannel amplifier the controller should first be set at 0dB.