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CD Recording FAQ
7. AudioCD
7.6. Comparing a copy to the original
Though you can easily make copies of audio cds, the question is whether a copy can be as good as the original.
Suppose that you make a copy ensuring that everything is identical to the original, including offset and track intervals. This copy can be identical to the original, but it may not sound as good as the original, especially if the original is a pressed (silver) cd.
The point is that you can make a copy of an audio cd which can be identical to the original concerning its content, but not its playback. The reason for this has to do with the nature of cd recording.
Due to the fact that audio cds suffer from lack of a crucial error correction layers, during their playback the audio signal may not be properly retrieved. CD players make up for this by interpolating audio samples, but often a copy may sound dull and faded compared to the original, and not as clear and vibrant. This copy, however, may still be a perfect copy if you extract the contents of both the copy and the original and make a binary comparison of them.
This is directly related to the quality of the written cds. During the recording process, mechanical vibrations and power fluctuations affect the accuracy of the laser beam, especially when media of lower quality are used. Combined with the lack of the extra error correction layer, these errors, which are present on any home written cds, show up during audio playback.
This depends not only on the quality of the recorder, but also on the quality of the playback device. While everything may sound fine when using a computer based cd reader and cheap multimedia speakers, differences may show up when using a hi-fi cd player and speakers.
High end stand alone audio cd recorders, like the ones produced by Marantz,
are designed so that mechanical vibrations and signal noise are kept to
a minimum, so that their design offers them the advantage of more precise
positioning of the laser beam. However, the difference may not be audible
when playing back using common and rather cheap players.