Audible Audio file conversion - How To - A Thorough Guide

I had posted back in May. I've since added a few more details.

Unfortunately Audible doesn’t offer any means whatsoever of supporting the use of their proprietary aa format (modified mp3 I believe) on mp3 cd players like the Rio Volt.

Conversion to mp3 seems the best alternative. When doing this, I’ve found that it’s nicest if the files are broken into tracks that are 3 to 5 minutes long. Goldwave will save the file into mp3 and split the files at points of silence in the recording. A nice feature!

To convert .aa to mp3s that are _ min long segments:
1. Open aa file in Goldwave providing your username and password (if this is the first file you’ve opened since installing codec (installed with audible manager)). Either select 'all files' from the dropdown or right click on the file, choose ‘open with’ and choose Goldwave.
2. ‘Trim’ any noise out of the first ~0.03 seconds: View, Zoom1:1, left click just to the right of the initial waveform, Edit, Trim, then to get back, View, All.
3. Set points for splitting: Tools, Cue Points, Auto Cue (my prefs are -30dB, 0.5 sec, 3min), OK, Close.
4. Save as wav (PCM signed, 16 bit mono)
5. Split file by: Tools, Cue Points, Split file, (saved as small 3 min long wav files), Close, then optionally close the wav file.
6. Encode the split files to mp3: File, Batch Processing, Add Folder, OK. Specify mp3 attributes on ‘convert’ tab (my prefs are Layer3, 24000Hz, 32kbps, mono), specify destination folder on ‘folder’ tab. Begin. Once finished encoding, OK, Cancel. Quit Goldwave.
7. Optionally, delete the wav files (both the single large and the small split ones to save disk space) – Done.

At roughly 14 MB per hour (of mono 32kbps), I can get well over 40 hours of listening time on one CD.

Time required to do the conversion is mostly waiting on the computer to process large files. I just timed a small 8 MB, 35min file. It took 3.5 minutes of my time to get it going (steps 1 to ‘begin’ in 6), then another 2 minutes to batch encode into mp3, for 5.5 minutes total. A larger file will take longer to get going as most of that 3.5 minutes is still spent waiting on the computer to deflash to disk, save as a wav, and split the file. (athlon xp1700+)

If you prefer to have the file as one large mp3 in addition to the small segments, you could alternately:
1. Open aa file in goldwave providing your username and password (if this is the first file you’ve opened since installing codec (installed with audible manager)).
2. ‘Trim’ any noise out of the first ~0.03 seconds.
3. Save as MP3 (my prefs are Layer3, 24000Hz, 32kbps, mono)
4. Tools, Cue Points, Auto Cue (my prefs are -30dB, 0.5 sec, 3min), split file (saved as small 3 min long mp3 files)
5. Done. Advantage is that you have the complete file as one mp3, disadvantage is that there is more encoding time.

Note that if you have a lot of aa files to convert, you can:
1. Batch Process all aa files to mp3 in one shot.
2. Do step 2 from above “Trim”, then do step 4 from above “auto cue” & “split” for each of the new mp3s.

This is using Audible Manager 3.5 and Goldwave 5.04. Good luck.
Note the more recent versions of Audible Manager include a codec that currently hangs Goldwave on opening the aa file. The older codec that comes with Audible Manager 3.5 does not.

Here is the link for AudibleManager 3.5.
http://download.audible.com/AM35/CD/AM_CDBurner.exe

Be sure to COMPLETELY uninstall AudibleManager before installing a different version. You should first find and save your aa files to another folder. (search files and folders for *.aa)

(I tried 3.6 once without luck, but didn’t exhaustively try it. If you get it to work, I want to know. Here is the link for AudibleManager 3.6.
http://download.audible.com/AM36/ActiveSetup.exe )

Note for Rio Volt users: In addition to the published limit of 999 files per disk, my SP250 seems to have a maximum number of filename characters per directory that it will handle. As I recall, it choked on 200 files that had a filename of ~30 characters. If I split them into different directories, it was OK, or if I shortened the name way down (~7 char) it was OK with 400 files. Best to keep the filenames rather short. And manual navigation (when you’re trying to get back to a particular part of a story) is easiest if they are put into directories of ~30 files per directory anyway.

Renaming lots of files? Try “Better File Rename.” It is a very flexible tool that allows you to rename files and folders very easily. It should have come with Windows. Very much worth the shareware fee.

BTW: The guy that has put together Goldwave has done an awesome job. I think he is exceptionally deserving of the shareware fee. I encourage everyone to support efforts like this one by purchasing the programs.