[pla3rhat3r]

This has been an age old question since Mp3s were created. However, I'm going to disagree with you there on saying that CD quality = 192kb. I've heard 192kb files and they sound like complete garbage. If you're looking for true "CD quality" that would be LPCM 44100 Hz 16 bits stereo for a bitrate of 1411 kbps.

[kaoD]

> I've heard 192kb files and they sound like complete garbage.

I'm curious, did you blind test yourself? I blind tested a friend of mine who kept saying so, and he did barely better than random.

[pla3rhat3r]

It really does depend on the file. However, if we're talking about most 192KB music files, they tend to sound "tinny" or shallow. There's not a lot of depth to the sound as compared to quality you would get from a CD.

[aianus]

It's very easy to tell the difference between 192kbps and FLAC if you have a decent subwoofer and the song ever goes below 30hz. On run-of-the-mill speakers and earbuds, probably not.

[mrob]

It's extremely rare for music to contain anything below 30Hz. Even below 40Hz is rare. The only place you're likely to find such low frequencies is sound effects in movie soundtracks.

[aianus]

I'm sorry, I pulled that number out of my ass.

I should have said 'if the frequency goes sufficiently low'.

[peapicker]

Unless you are into Bassnectar and the like... ;)

[mrob]

Interestingly, a lot of "bass heavy" music focuses on frequencies around 50Hz, not the really deep sub-bass. This makes sense when you consider human hearing. Those higher frequencies sound much louder to us, and they're still low enough to get the tactile feeling.

[dkonofalski]

I've heard this before elsewhere and the response then was that the person was confusing kilobits with kilobytes. 1411kbps/8bits/byte = 176.375Kbps. The closest you can get to that is 192Kbps. There's a big difference there.

[adrianpike]

MP3 bitrates are conventionally given in kilobits per second, not bytes.

[goldcountry]

From Wikipedia's page on Compact Disc Digital Audio:

Each audio sample is a signed 16-bit two's complement integer, with sample values ranging from −32768 to +32767. The source audio data is divided into frames, containing twelve samples each (six left and right samples, alternating), for a total of 192 bits (24 bytes) of audio data per frame.

https://en.wikipedia.org/wiki/Compact_Disc_Digital_Audio#Dat...

[pherq]

That has nothing to do with the bitrate -- the fact that you're getting a different unit on your 192 should be in an indication (bits or bits/frame, as opposed to kilobits/second).

CDs store audio as 16 bit samples, with 44100 samples per second. This gives a bitrate of 16 bits * 44100 Hz = 705600 bits/second (705.6 Kbps). This is per channel, so the total bitrate of the format is 1411.2 kbps, as stated (modulo rounding) by the GP.

EDIT: in fact, the article you link specifically says (a couple sections further down) that the bitrate is 1411.2 kbps.

[omribahumi]

This means CDs should have ~800MB of usable space. Why only 700MB?

    705600 * 2 = 1411200              # bits/s for stereo channel
    80 * 60 = 4800                    # seconds in 80 minutes
    1411200 * 4800 = 6773760000       # bits in a 80 minutes CD
    6773760000 / 8 / 1024 /1024 = 807 # In MB

[dagw]

Error correction.

While a 'raw' redbook CD can hold ~850 MB, it is standard to included error correction codes so that a slightly scratched CD can still work.