A non-linear control system for loudspeakers significantly reducing distortion in the form of harmonics and intermodulation.
With full-sized loudspeakers used at low excursion it’s not a big issue, but when the speaker is being pushed close to it’s limits, this distortion becomes more and more audible.
Today this issue has increased with the miniaturization of speakers for TV’s, laptops and mobile devices. These speakers often lack a spider, making them asymmetrical and much more non-linear in their dynamics. That in combination with wider unit-to-unit tolerances gives new challenges, requiring new levels of control.
This technology is based on a system for compensating loudspeaker non-linearities with a minimum amount of feedback (a specific non-limiting example is with pure current feedback), for cost-efficient implementation in CE devices. Many have tried with feed-forward or limited feedback approaches, but without success in practice.
One reason is likely the changing nature of model parameters due to aging, heating or other environmental aspects. In this application we also disclose a novel way of tracking these slow dynamics over time without adding significant computational power.