Although we work with a kind of assembly line idea, everyone understands the entire product construction process and can perform any part of it. We have also worked with our suppliers so that they understand the importance of component tolerances. For example the top plate and pole piece have to be machined to very high tolerances because any fluctuation in the width of the magnetic gap has a direct impact on the frequency response. Having perfected the tooling and manufacturing techniques we achieve a very high degree of consistency with production failures almost non-existent. An important aspect in achieving such low failure rates is the careful inspection of component parts before assembly.
Every unit is tested before final assembly and then carefully measured again after assembly.
The result is compared with a reference unit to ensure complete consistency in specifications. This doesn't affect the frequency response at all because the airflow is so small at that point in the throat of the horn. In the three years of production of the 1401M several improvements have been made to enhance reliability, for example, the most recent change being a new coating process to increase the life of the diaphragm by preventing corrosion. Most of these improvements have come through exhaustive experiments and testing. For example frequency response improvements resulted from studying the interaction of the phasing plug, the suspension stiffness, the voice coil resistance, and the optimum gap width.