INFORMATION ABOUT AUDIO CD AND MP3 CD

Audio CD

An audio CD (Compact Disc Digital Audio) is one that you buy from stores and contains only audio tracks. You can play an audio CD in any CD players, including your car CD player, and your computer CD-ROM. The standard for Audio CDs is called "Red Book".

The audio tracks are uncompressed digital data (essentially WAV). When you look at the contents of an audio CD, you may notice the files are .CDA files. A CDA file simply points to the location of the audio track on the CD. You cannot just copy these CDA files to another location since they are just "pointer" files, contain no audio data. The actual audio data is stored on the CD sectors and cannot be viewable on your computers.

An audio CD normally can hold up to 74 or 80 minutes of audio. So when you create an audio CD from some MP3 files, for example, no matter how big or small your mp3 files are, the CD can only fit in up to 80 minutes of audio.

Pro & Con

Audio CD is a very first generation of digital audio compact disc and because of this, audio CD can be played on any CD players.
However, an audio can only hold up to 80 minutes of audio. This is about 10-15 songs if the average length of the songs are 4-5 minute. Not much at all! if you want to put more songs onto a CD, you'll an MP3 CD.



The frequency response: from 20 Hz to 20 kHz.

Bit rate = 44100 samples/s × 16 bit/sample × 2 channels = 1411.2 kbit/s (more than 10 MB per minute)
Sample values: range from -32768 to +32767.
On the disc, the data are stored in sectors of 2352 bytes each, read at 75 sectors/s.



MP3 CD

An Mp3 ("MPEG-1 Audio Layer 3") file is just like a computer data file. The Mp3 format is audio encoding format, sometimes called "compressed" format. The Mp3 format was invented by a team of European engineers at Philips and became an ISO/IEC standard in 1991.


Late 1990s, the internet users started to encode more and more audio files using the Mp3 format and spread them over the internet. This lead to the creations of many Mp3 player software such as WinAmp, Nullsoft, etc... The Mp3 format became the most popular audio format for computer because of the advantages of it.


You can compress an audio track from 40-50 MB to create an mp3 file of 4-5 MB with the same quality. Well, the quality actually depends on the encoding methods. The low bit-rate would give you a smaller Mp3, but with lower quality.


Pros & Cons

An Mp3 CD can hold up to 700 MB of data/mp3 files. If you have Mp3 files with an average of 4-5 MB each, for example, you can store up to 160 songs on a CD, about 10 times of an Audio CD.
However, not all CD players can play Mp3 CD. More and more CD players are now Mp3 compatible, but not all of them. So you might need to question yourself when you want to create an Mp3 CD; for example, if the target CD player can handle it.