"Bass tones" refers to low-pitched sounds produced by instruments like a bass guitar or drums. These tones are deeper and have a lower frequency compared to other higher-pitched sounds. Full definition
The subwoofer performs surprisingly well for its size and is able to reproduce deeper bass tones than I was expecting. (techradar.com)
You'll find the speaker grill on the front and a more rugged plastic grill underneath the speaker which pushes out those lower bass tones. (androidcentral.com)
It uses a 2.1 channel setup comes with an included subwoofer for great bass tones. (geekwrapped.com)