When the CDX-1 has a a formatted "High Seed" CD-RW in the drive you can record audio tracks. However if you are using the pad sequencer you will be limited as to which tracks are available to record on to.
When using the pad sequencer:
Pad sequence A replaces tracks 1 and 2.
Pad sequence B replaces tracks 3 and 4
Pad sequence C replaces tracks 5 and 6.
Pad sequence D replaces tracks 7 and 8.
When using the pad sequencer:
Pad sequence A replaces tracks 1 and 2.
Pad sequence B replaces tracks 3 and 4
Pad sequence C replaces tracks 5 and 6.
Pad sequence D replaces tracks 7 and 8.