A to adjust the tone quality, Turn [bass] to adjust the low frequency sound, Turn [treble] to adjust the high frequency sound – Panasonic SC-HT280 Manuel d'utilisation

Page 22: В to adjust the sound balance, C to adjust the subwoofer level, Press [subwoofer level, For your reference, D to adjust the subwoofer low pass filter, Press [subwoofer low pass filter, To adjust the tone quality