Geoffkait
I dont have any opinion about whether or why a CD copy sounds better than the original. My earlier post was directed solely to your comment that larger pits on a CD copy couldnt be a reason they sound better than an original CD, because Blue Ray discs, which sound better than CDs, have pits that are smaller than the pits on CDs. On that position, I have a comment and a question.
Comment
In your response to me, you elaborated that a smaller pit size allows more pits (and bits) to be placed on a Blue Ray disc, providing more information, greater detail and better sound. I agree with your observation that a Blue Ray disc can hold more information than a CD, but that explanation relates to how many pits there are, not the way the laser reads the smaller pits.
A CD original and a CD copy contain the same number of pits, even if the pits on the copy are larger, so the amount of information on the original and the copy is the same. The reason the Blue Ray is superior to a CD, namely more information, does not exist when comparing a CD copy to a CD original. Therefore, the smaller pit size of Blue Ray and the superiority of its sound do not together support the conclusion that a smaller CD pit size would improve CD sound or the conclusion that it would be impossible for a larger CD pit size to improve CD sound.
Question
I understand that smaller pits on a Blue Ray disc (and a smaller wavelength laser that can read the smaller pits) allows more digital information to be squeezed onto the disc, but how is the additional information translated into more detailed sound? The Blue Ray article on Wikipedia has a table of audio formats used for Blue Ray. This table shows much higher bitrates for Blue Ray formats (as much as 24.5 MBit/s) compared to CD (1,441.2 Kbit/s), which means much more digital information could be read per second. However, the table also shows the number of bits per sample for Blue Ray audio formats is either 16, 20 and 24, the same numbers as for different flavors of CD. The same table also shows sample rates of 48, 96 and 192 Khz, all of which are also available on CD. Although Blue Ray can read more information per second, it appears that it reads the same size samples at the same rate as CD, so how is the greater amount of information stored on the disc being translated into better sound? Is the superiority of Blue Ray format only a future possibility awaiting a new digital format with larger samples and/or higher sampling rates? If Blue Ray currently sounds better than CD, is it mostly the result of multi-channel versus stereo spatial presentation?