The Acton II Bluetooth includes three controls for adjusting the audio.
1. Volume Knob
Adjust the loudness with the volume knob. The volume greatly affects the playtime of the battery. Set it to five (right in the middle) for an optimal volume-to-playtime ratio
2. Bass Knob
Use the bass knob to adjust the low-frequency audio output. The default position is five (right in the middle), also known as flat or unaffected EQ.
3. Treble Knob
Use the treble knob to adjust the speaker for clarity and shrill high frequencies. The default position is five (right in the middle), also known as flat or unaffected EQ.
NOTE: The audio can also be adjusted from the Marshall Bluetooth® App