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One of our Walmarts has anti-theft wheels
(lemmy.world)
None of the others in town have these, thought it was unusual enough to share
It's just going to be pulses of an 8khz signal. Why would an MP3 not encode this just fine?
Like I said before, the coincidence is what's remarkable.
It’s a bit of a coincidence that the signal is in the audible range, for sure! I’m not too surprised that an MP3 can reproduce a digitally modulated sin wave in the audible spectrum, but I can see how it’s surprising to people that a sound card is basically a dinky low frequency SDR. Van Eck Phreaking is another good example of this kind of stuff. CRTs in particular produce very obvious emissions which match what’s being displayed.