Is 44.1 KHz Sampling Rate High Enough? (Audio Sampling Rate Experiment)

YouTube's compression limits the frequency to 17 KHz which has nothing to do with the uploader's original file. I used his video because that's the best I can find (   • Hearing Test HD  ). I can get around the 17 KHz YouTube's frequency limit by speeding up his video that it is even possible to get a sine wave at 10 KHz by speeding up the 2.5 KHz 4 times that it became 10 KHz. But when I rendered the 10 KHz sine wave using 44.1 KHz wav it still became steeper and looks more like a triangle wave which can be seen at 8:37. That's because at 44.1 KHz sampling rate it can only get four samples at 10 KHz. I don't hate CD, I like CD I just want to reveal the limitations of 44.1 KHz sampling rate because most people 50 years old and younger can still hear a 10 KHz tone but no idea if you can hear the difference between a sine wave and a triangle wave at 10 KHz. I made this experiment because of accusations that CD's 44.1 KHz is not high enough that high frequencies don't sound right. You don't see a stair step on waveform, it just connect the samples to form a wave which is also how most D/A converter works.