Speaker distortion compensator

DETAILED DESCRIPTION Methods and systems in accordance with the invention nullify or substantially eliminate the effects of spurious emanations from simple source transducers that are excited with complex waves.
The spurious simple source emanations are reduced to effectively inaudible levels by electronic interaction with the transducer prior to or during excitation.
Each individual transducer, or group of transducers for a particular frequency, is driven separately from transducers for other frequencies.
An input signal covering the audio band is subdivided into different frequency ranges, and each signal is processed through an analog circuit presenting a model of the associated transducer dynamics including mass, compliance and damping of the transducer, the voice coil of the transducer and the acoustic load into which it operates.
The analog circuit introduces compensation into the signals in accordance with the response image of the transducer, so that the transducer velocity variations result in pressure waves that correspond to the original input signal in precise fashion.
The processing circuits are exemplified by active and passive circuits which provide a feedforward component which nullifies the spurious emanations that would otherwise develop as the transducer attempts to follow complex motions that are otherwise essentially impermissible by virtue of its dynamics.
Both voltage mode and current mode exemplifications are disclosed.
In different examples of systems in accordance with the invention the processing circuits may include compensation for a ported speaker enclosure.
It is also a feature of the invention to arrange the crossover network such that a spurious signal component is deliberately introduced for one speaker in a crossover region, so as to provide certain advantages in speaker response.
However, an opposing signal component is also introduced in the crossover region for the speaker in the next lower frequency region, and the signal components are acoustically cancelled