Yo!
Usagis big problem is that it can accept bad bcstms without any error messages so first of all I highly recommend switching to Kame editor. It has a smoother workflow AND a build in BCSTM converter that will let you know if your music track can be correctly converted.
Here's a trial and error learned recipe for success when it comes to theme bgms.
- No bigger than
3371008 bytes. Remember to check bytes since 3.3mb can mean a lot of things.
- Prepare a .wav file to convert. (This might just be my superstition but it never failed me so it might be worth adopting as a "best practice" thing).
- Export the .wav using shift + ctrl + e and make sure to export it with 16-bit encoding or 8-bit encoding (
VERY IMPORTANT - bcstms will never play if they have over 16 bits per sample!!!)
-Using kame editors converter automatically writes looping data and has never failed me so I sincerely recommend using kame even if only for it's converter.
-Enjoy your properly working bcstm
One more tip. You shouldn't set your sample rate to anything higher than 32000 hz since the 3ds speakers can't realistically produce audible differences for sample rates higher than 32khz. This will help you decrease filesize a bit.
Two more tip. The music playing in previews is actually from a separate .ogg file so if you want your theme preview to have audible music you need to export an additional file in the .ogg format, rename it to bgm.ogg and place it in the zip folder of your custom theme. Ogg files are really small due to being a compressed file format so they shouldn't add much bloat to your theme.
Attached is how your export window in audacity should look like to guarantee success.
