laptop soundcard impulse repsonse shown on an oscilloscope. the response is a sinc(t) function, i.e. sin(t)/t. the oscilloscope cursors are positioned on the two symmetric first minima, and shows a difference of 60 us

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   teddy (tedyapo@fosstodon.org)'s status on Saturday, 16-Aug-2025 06:17:00 JST teddy

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   i've had to turn to other things for amusement. i measured the impulse response of the laptop soundcard: output a single nonzero sample, and the soundcard yields its impulse response. the time between the two minima shown is 60 us. if i did the math right, this corresponds to a low-pass filter with a cutoff at 23.8 kHz

   i am revising my opinion of this soundcard. it's good as an audio device, but i want a first-order-hold instead of a reconstruction filter for these time-domain shenanigans