Subwoofers are designed to represent the bass frequencies from your music. However, they also relieve the low-end burden on woofers and mid-bass by applying earlier low-pass filters to those speakers and allow them to play to their intended frequency range.
The Dynaudio Esotar 2 1200 is a powerful reference grade subwoofer intended for the most ambitious, state-of-the-art mobile audio systems. The frequency response curves confirm that the Esotar 2 1200...