If you want to be able to play your backups on (almost) any standalone DVD player, I can highly recommend â€˜Audio DVD Creatorâ€™. Personally I prefer to backup my CDâ€™s to PCM 48 kHz/16 bit, which is a lossless format. That way each DVD can contain 6-9 CDâ€™s, but itâ€™s possible to store about 45 hours if one use AC3 192kbps, which is a lossy format. You can also create a menu
With â€˜Audio DVD Creatorâ€™, that makes it easier to navigate between the tracks.
If you just want to store your files on DVD with no need of playback on your standalone, you could compress your wav files with 'MonkeysAudio' and burn a data-DVD with your files. That way youâ€™ll gain about 35% of space on your DVD. 'MonkeysAudio' creates files with anâ€˜Apeâ€™ extension, which is a lossless format.
â€˜Audio DVD Creatorâ€™ is unfortunately not free, but there is a limited trial available on their site.
Keep in mind that when you encode to MP3/AC3 format, you are losing audio quality.