We all have heard of the ISO image format which is a very popular way of backing up data CDs & DVDs. A very easy way of creating an ISO image in linux is by using the dd or dcfldd command. Similarly, in Windows, applications such as Nero have an option to save a CD as an ISO image file. However, when it comes to audio CDs it is not possible to backup them as ISO image file as they have multiple tracks. Here are two ways to create an image of audio cd for archival purposes.
cdrdao is free software for authoring and ripping of CD-ROMs. The following command I believe will help in creating an almost exact copy of the audio CD.
# cdrdao read-cd -v 2 --device /dev/cdrom1 --datafile audiocd.bin --read-raw audiocd.toc
This is the same command used by Brasero when making a copy of an Audio CD.
I have also come across a command "readom" which has a "--clone" argument that is used by k3b in its "Clone Copy" option for audio CDs. However, I've read in a lot of forums that this does not backup the audio CD in a reliable way. That is when the image is burnt back to another CD, it may not be playable by all audio CD players. However, I think this command may be useful to backup data CDs with sector errors.