The picture below is of the subwoofer units tuned port. This building technique is basically a specifically measured piece of tubing that extends into the subwoofer unit. The specific length of the tube allows the speaker designer to “tune” the port to a specific bass frequency that the designers want to emphasize as the volume of air inside the tub will vibrate at a set frequency.

The subwoofer can be called a “down firing” unit as most of the bass energy and power is directed downward. The base feet on the subwoofer are a taller than normal allowing the bass energy to radiate down and outward from the driver. Considering the size of the subwoofer the XPS sub can actually produce a good amount of bass energy without being boomy or muddy.

The back of the subwoofer unit also contains the bass adjustment knob which allows the user the increase or decrease the amount of bass the subwoofer will produce. This control allows you to set the bass amount and match it more accurately to the position of the subwoofer or adjust the balance of bass to higher frequencies.