6 Modelling Accuracy

The effectiveness of the Smart amp depends on the internal profile of the speaker being accurate. But speakers are not static objects: normal manufacturing variation means no two units are perfectly identical, and a given speaker's behavior can shift with age, temperature, and general wear. If the internal profile silently drifts out of sync with the real, physical speaker, the prediction mechanism built on top of it (excursion estimates, temperature estimates, all of it) becomes less trustworthy.

Smart amp addresses this by continuously cross-checking itself. It compares what its internal model predicts the speaker's electrical behavior should look like against what the sensing circuit actually measures. Any mismatch between prediction and measurement is treated as an error signal, and the model's internal parameters are adapted to reduce that error as much as possible. This is conceptually the same idea as a car's GPS navigation constantly re-checking its position against fresh satellite signal rather than trusting a single initial reading for the whole trip — small, continuous corrections keep the system updated, instead of letting small errors accumulate unnoticed over weeks or months of use.

The initial profile of the speaker is generated by sweeping the speaker with test tones across a range of frequencies and measured how its electrical impedance and physical movement changed, tracing out a curve that peaks sharply around the speaker's natural resonant sweet spot, the frequency at which it vibrates most easily. Away from that sweet spot, in either direction, the speaker naturally moves less for the same input.

The speaker's heating behavior is measured by driving it with known power and tracking how its temperature rose and fell over repeated test bursts. That agreement between prediction and these measurements is a key point of the Smart amp technology: it is about inferring hidden, unmeasurable quantities (motion, heat) from things that actually can be measured (voltage, current) and working reliably enough with real hardware, in a real product, protecting a real speaker.