The internal partitioning provides substantial bracing for the entire structure, reducing cabinet flexing and colouration. The inside faces of the duct or line, are treated with an absorbent material to provide the correct termination with frequency to load the drive unit as a TL. A theoretically perfect TL would absorb all frequencies entering the line from the rear of the drive unit but remains theoretical, as it would have to be infinitely long.
The internal structure of the cabinet provides support and reduces flexing, minimizing coloration. The inside surfaces of the duct or line are treated with absorbent material for proper termination and frequency loading of the drive unit as a TL. A perfect TL would absorb all frequencies entering the line from the rear of the drive unit but is purely theoretical due to its infinite length requirement.