TPT couples the rear output of the bass drive unit to the air in the room via a column of air in the cabinet. This column is tuned to optimise the output of the bass unit at low frequencies in the same way that the air columns in a pipe organ transfer energy efficiently, so the listener feels, as well as hears, the low frequency output. TP or The ‘Twin Pipe’ refers to the internal layout where the drive unit is positioned part way down a folded, tapered column. This exits through the base of the cabinet and is mass loaded by the air trapped between this ‘port’ and the plinth.

The result is deep, tuneful, well-defined bass from speakers that are easily accommodated in a wide variety of room shapes and sizes.