The key difference between a 2.0 and 2.1 soundbar is the presence of a subwoofer. A 2.0 soundbar has two channels (left and right), providing stereo sound. A 2.1 soundbar includes a subwoofer and two channels, enabling deeper and more impactful bass. A 2.1 soundbar enhances the overall audio experience—especially for movies, music, and gaming—by adding depth and thump to low frequencies.