Abstract: Driver for an acoustic transducer having a moving coil of substantially equal length to the air gap. The air gap may itself be extended in length using an upper or lower lip, or both. A stationary coil is also provided. The moving and stationary coils can be controlled by suitable control blocks to form an electromagnet-based transducer with reduced distortion.

Abstract: Driver for an acoustic transducer having a moving coil of substantially equal length to the air gap. The air gap may itself be extended in length using an upper or lower lip, or both. A stationary coil is also provided. The moving and stationary coils can be controlled by suitable control blocks to form an electromagnet-based transducer with reduced distortion. The acoustic transducer may be a hybrid acoustic transducer.

Abstract: This invention relates to acoustic drivers with stationary and moving coils. Time varying signals are applied to the moving and stationary coils to control the movement of a diaphragm, which produces audible sound. The time varying signals correspond to an input audio signal such that the sound corresponds to the input audio signal. Some of the described embodiments include multiple moving coils, multiple stationary coils or both. Some embodiments include feedback for adjusting one or more of the signals based on a characteristic of the acoustic driver. Various compensation and other features of the invention are also described in relation to various embodiments.