Lowther drive units come with two interchangeable versions of phase plugs fitted to the center of the inner cone diaphragm. These are also called ”stabilizers” since they also have the function of horn loading the inner cone for higher efficiency and to decrease cone break-up. Both the standard and the large diameter ”full Stabilizer” cause phase relationships which result in characteristic throughs and peaks of the frequency response. These specific irregularities are dependent upon the geometric relationships of the diaphragms and the stabilizer, not the enclosure design.

Audiolive can provide a phase plug which improves the frequency response and the audible qualities of the Lowther drivers. Much research and development went into this project which also considered horn design to the geometric form between the stabilizer and the inner cone. The end result is a simple design which takes the sound reproduction of the superior Lowther units even closer to that of a live performance.