Can the Clip+ play AAX enhanced Audible or only from the Zip?

And your guess: AAX is a DRM-ed MP3 or AAC?

I believe that is a propritary format by Audible and yes, the Clip+ should be able to play them provided the player is set to MTP mode and has been authorized via Audible.

Audio: MP3, WMA, Secure WMA, Audible, OGG Vorbis, FLAC


My apologies ahead. But I think that’s the only supported ones for Sansa Clip+? 

Yes. See that word “Audible”?  AAX is an Audible format. Apology accepted.