[mbell]

> Significant noise power at ultrasonic frequencies (or even a skewing towards higher audible frequencies) represents a problem for tweeters & amplifiers both in terms of the intermodulation distortion mentioned in the article and in terms of power dissipation at the business end. IIRC Dell and VLC are having a falling-out because VLC's soft clipping is damaging the speakers in certain Dell laptops.

Dell probably didn't bother putting an analog reconstruction filter on their DACs, assuming they used an average Realtek codec the digital filter in the DAC has a minimum cutoff point around 28khz but could be higher when operating with higher sampling rates. They probably also sent the signal into a filterless class D amp to drive the output. Those two things together add up to a lot of ultrasonic crap in the signal.