You can change how loud the bass is on the Sony XB21, by turning on and off its bass boost…
You can change how loud the bass is on the Sony XB20, by turning on and off its bass boost…
You can change how loud the bass is on the Sony SRS XB20, by turning on and off its bass…
You can change how loud the bass is on the Sony SRS XB33, by turning on and off its bass…
You can change how loud the bass is on the Sony XB33, by turning on and off its bass boost…