You're probably right. I looked at Neumann ("Independent soft clip, peak and thermo limiters for woofer and tweeter; Woofer excursion limiter; thermo limiter fo

You're probably right. I looked at Neumann ("Independent soft clip, peak and thermo limiters for woofer and tweeter; Woofer excursion limiter; thermo limiter for the electronics and amplifiers") and Genelec (https://www.genelec.com/key-technologies/protection-circuitry https://www.genelec.com/key-technologies/protection-circuitr...) for info - as they're the reference in the monitoring world - and my guess is that it's implemented like Apple, via some simulation function from time-integrated wattage and frequency to bool (limit on/off). Apple isn't the first to use advanced limiters to get the most of loudspeakers, if I remember well, this trick is what allowed Devialet to make the Phantom what it is. Which is why loudspeaker measurements should _always_ include something like this: http://0x0.st/XG1y.png http://0x0.st/XG1y.png