Lambda 001 Motor Design
Nick McKinneyThe Lambda 001 motor was designed by Nicholas McKinney from Lambda Acoustics Inc.  Designed over the period from 1997~1999, tremendous effort was given to create the lowest possible distortion. The Lambda drivers now live on as the Lambda Series from AE Speakers. Below is information describing the intricate details of the low distortion motor design.
Part 1: Defining the Requirements for a Low Distortion Driver
The ultimate design for low distortion should have the following characteristics:
(1) Linear magnetic flux levels across the entire VC movement range.
(2) The flux should be fixed permanently and not move, this is however not the case in 99% of speakers.
(3) High heat absorption properties as close to the VC as possible. The VC if allowed to heat significantly will lower the speaker output Spl very quickly.
(4) Linear inductance as the VC moves through its entire range if the driver has to contribute ANY output above the impedance minima above the Fs of the driver. This is not just at the crossover point, this is any output that is not -48dB down in our opinion. The only way to accomplish this is to keep the CORE of the VC the same at all excursions. The VC is after all an inductor, however this is the only inductor in the whole audio system that varies it's value with low bass excursion. The low bass creates massive excursions that at the same time changes the parameters of the driver at higher frequencies with every deep in and out stroke.