The Quality of Sound in CDs

Recently I prefer to use lossless codecs instead of mp3. In many cases, bitrates affect the quality of sound: the higher bitrates the better quality. I wondered how many bitrates CDs have, so I searched and found it.

16 bits · 2 channels · 44100 Hz = 1411.2 kbps

"16 bits" means the quantity of data in one sample. "2 channels" means stereo: right and left sounds. "44100 Hz", or sometimes "44.1 kHz", means the times of calculations in one second: CD players calculate samples 44,100 times in a second.

How much data does music need? Many albums contain over 60 minutes. Let's think about a just 60 minute CD.

1411.2 kbps · 3600 seconds · 1/8 = 635,040,000 bytes ~ 635 MB

"1/8" means conversion units from bits to bytes.

CD-R/RW have usually 650 MB, but some have 700 MB. We can recond music about 60 minutes in 650MB CDs and 70 minutes in 700MB CDs.

650 MB · 8 bits / 1411.2 kbps ~ 3685 seconds = 61 min. 25 sec.
700 MB · 8 bits / 1411.2 kbps ~ 3968 seconds = 70 min. 8 sec.

But unfortunately we can't use maximum spaces. Some spaces are necessary in addition to spaces for recording music when we write onto discs. This happens with DVDs and Blu-ray Discs, too. We can know this when we format blank discs. Perhaps makers will say, "It's because of the standards."

I like the spelling of "disc" better than that of "disk".