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Ask HN: Why is all web streaming only CD Quality at most?

1 points by listic ↗ HN
Why are internet broadcasting sites only work in CD Quality at most (16bit/44.1kHz), or more likely, 320 kbps mp3?

I have bought a sound card that supports 24bit/192kHz sampling (E-MU Tracker Pre), and it is not exactly a new technology: this family of semi-pro sound cards is 10-15 years old. Why is this higher fidelity standard not supported by any website? Is it an underlying limitation of some web standard?

8 comments

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db48x
24–bit audio is very nearly a scam. There's no perceptible difference between 16– and 24–bit audio. You could say that the human ear isn't sensitive enough to tell the difference, but it's better to say that 16 bits are sufficient to cover the range of volumes that a human can hear.
bcrl
Not only that, but modern audio mastering techniques overdue compression to make everything sound "louder" and eliminate the quite of audio of days of yore.
naikrovek
24-bit sound cards will often have 8+ bits of noise. None can provide can capture true 24-bit audio data.

Human ears are at their highest sensitivity level in the early teenage years. After that, it is all downhill in terms of what a human can hear.

The highest audio frequency a human can hear across their lifetime is about 20kHz, give or take a few hundred Hz.

It is true that audio data is captured in samples, and a naive way to view that sampled waveform is with a stairstep-type of a curve, but that is not how audio is stored. The gaps between samples is undefined, and is not defined as the nearest or most recent sample value. This means that when the original waveform is restored from the sampled audio, the only possible solution that fits the sampled audio points is the original audio itself. Bits per sample only changes the noise floor of the signal.

Audio is weird in this way. 44kHz 16-bit audio is capable of capturing any audio waveform that a human being can hear. There probably are exceptions to this rule who can hear, possibly, up to 23kHz or 24kHz audio, and there would only be a couple dozen of these people on the entire planet, and it is likely that they would not know how exceptional their hearing is.

IndySun
Isn't this a question of bandwidth? The less data sent over the net, whilst maintaining a decent level of quality, the better for the end user.

The question of the available higher sampling rates are most often used at the recording stage, to capture the highest quality possible. And 'highest possible quality' will of course depends on your microphone.

listic
I'm not so sure: there are internet radio stations streaming in 320 kbps (maximum bitrate supported by mp3), but I see none going above 16bit/44.1kHz, as if there's some kind of hard limit.
IndySun
Could you elaborate? I'm not sure of what you're 'not so sure of'.
listic
I am not sure the bit depth and sample rates of web streaming services are simply the question of conserving bandwidth and not the result of some underlying limitation of some web standard.
IndySun
Ok, thank you. I am not aware of any such limitation in any web standard. Any audio, and in fact 'all', information sent is converted to digital. Any amount of data can theoretically be sent. Receiving/demodulating, that data will depend on the internet service and equipment at your end - regardless of what is in that data, be it audio, video, imagery.

In reality, the general public does not have access to such powerful internet services so companies rely on compression codecs to supply things like 8k TV, and other media with high data rates.