Yep, but 8kHz is nearly twice the frequency of a piano’s high C (rightmost key). There are vocalists that can sing G10s (which is around 10k?) but they’re rare and not musically useful
It's not the base frequencies that matter, it's the harmonic sequence above the base note that makes for the difference between instruments.
Play with it yourself - record various notes, on various instruments, do the FFT to break it into the frequency domain, and you'll see quite a few harmonics over the base note. Strip those out, and it sounds muddy.
For those old enough, an analog phone line was typically limited to 300-3300Hz, give or take. It's more than enough to pass clearly understandable human voice, but neither it is the same as being next to someone.
There are also a lot of the high frequencies present in the sort of transients that cymbals and snare drums and such put out - and I'll suggest that most audio compression algorithms mangle them quite badly until you get up into the lossless or "may as well have used lossless" bitrates.
But that high C on a piano isn't a pure 4khz tone. There is a lot going on there above and below 4khz. You can prove this to yourself by looking at it in a frequency analyzer, or by simply listening to a pure 4khz tone and observing that it sounds a lot different than a piano. This is also why the same note played on different instruments sounds different.
If you lop off everything above 8khz, things sound "muffled", like you've put a thin blanket over the speaker.
No need to believe me, try it yourself in Audacity or any music playing app with EQ controls.
Not only that, but stringed instruments have a lot of frequencies in the first millisecond, right at the attack, until the string settles into its harmonic oscillations. This is very noticeable on a spectrogram and gives each plucked/raked/bowed note its distinctive character.
It is, and it's the data that a lot of audio compression algorithms manage to lose or mangle.
A plucked string in FLAC vs something like 128 or 160kbit MP3 sounds radically different. The same is true of the initial hit of a cymbal - they're just wrong when compressed.
Yeah. And I'm not even sure why this is controversial.
We all know that JPEG is a really good format, but like all lossy formats it struggles with sharp pixel-perfect text. More generally, lossy data compression struggles with those sorts of razor-sharp details.
I don't know why some fight tooth and nail against this in the audio domain.
In practice, yeah, MP3 is usually good enough. An isolated plucked string or cymbal crash is not something you come across too often. And that's why MP3 fares so well in listening tests against uncompressed audio.
But if you really want a full fidelity experience it's not the ultimate choice, any more than a JPEG of the Sistine Chapel is a 1:1 substitute for the real thing.
