[dreamcompiler]

You won't hear a trumpet suitably emulated by motors either. But that wasn't the question.

Any motor-based oscillator can be accurately emulated by a digital oscillator, so the answer to the original question is "nothing." But yeah, neither is good enough to emulate a trumpet played by a human.

[sideshowb]

The trumpet on my prophesy ain't half bad but yes I concede that point.

For synthetic sounds however, at this point I think it's mostly a question of workflow. Like yes you can take time to program all those imperfections into a digital sound. Or you can take time to make an analog device which has them inherently.

[WalterBright]

Motors always have imperfections, resonances, feedback from the room its in, etc. I don't know if they'd have enough for it to be audible.

[v1ne]

Indeed, motors are physical devices with their own imperfections. But … these are brushless motors, tightly controlled with a feedback loop. They, as they also say in their videos, very quickly follow input changes. I wonder how much weird effects you might hear on those.

[fuzzfactor]

Plus the only way to emultate it is to have the real thing as a reference beforehand.