Use the cdrw -l command to identify the CD writers on the system.
$ cdrw -l
Looking for CD devices...
    Node              |    Connected Device            |  Device type
----------------------+--------------------------------+-----------------
 cdrom0               | YAMAHA   CRW8424S         1.0d | CD Reader/Writer
 | 
If you want to use a specific CD writer, use the -d option. For example:
$ cdrw -a filename.wav -d cdrom2  | 
Use the cdrw -M command to to identify whether the media is blank or whether there is an existing table of contents.
$ cdrw -M Device : YAMAHA CRW8424S Firmware : Rev. 1.0d (06/10/99) Media is blank %  |