Servo Control of Loudspeaker Cone Motion Using an Optical Linear Displacement Sensor
Wolfgang Geiger · Journal of the Audio Engineering Society · 2005
Loudspeakers normally exhibit the highest harmonic distortion in an audio system. Large signals create nonlinear effects in the motor structure as well as displacement errors, which are caused by the non-linear force factor and stiffness. Both effects can be reduced by an optical linear displacement measurement and closed-loop control of cone motion. The absolute value and the phase of the cone displacement are defined by the controller and not by the loudspeaker. This is particularly important for arrays.