The interior gear also allows for a full range of EQ controls. From the Marshall app on your phone, you could make a number of adjustments to get the sound you would like. To the speaker itself, You should use the brass control panel to adjust bass and treble. https://www.bluetoothspeaker.top/portable-ipx6-90hz18khz-waterproof-speaker-wireless-outdoor-bt5-0-bluetooth-speaker/