Converting to ADX for poneSound

I have been trying a number of different resources to covert some files (mp3 and wav) to ADX for use with poneSound, but I have had no luck. Resources I have found won't let me adjust the bitrate.
Can someone recommend a tool that they use or point me in the right direction?
Install ffmpeg and use these arguments (or this batch file):

SET /P this=FILE:
ffmpeg -i %this%.mp3 -c adpcm_adx -ac 1 -ar 15360 %this%.ADX
ECHO this %this%

ffmpeg -i filename.mp3 -c adpcm_adx -ac 1 -ar 15360 filename.ADX

you can adjust the batch file as needed