Creating Audio Files
Now you know it all works, you'll need to create your own audio files. The sound board does not support MP3 so if you
have your audio clips in MP3 format you'll have to convert them to OGG or WAV
You can use
either
OGG or WAV format, and you can 'mix and match' so some files are OGG and some are WAV
There's some pro's and con's to the two formats:
OGG is compressed, but still sounds great. It uses much less space so if you want to say store a full 2 or 3 minute
song, you'll need to go with this. However, it does take a few milliseconds to start playing the file, so if you want
to have perfectly looping audio, OGG will have a gap in between each play through
WAV is uncompressed, so its the highest quality. But it takes up a lot of space. Since it's uncompressed, it starts
playing instantly, and if you're looping an effect, this will have no discernable gap.
If you want to use your own sound files, you can! Record, sample, remix, or simply download files from a sound file
sight, such as freesample.org. Then, to make sure you have the files converted to the proper specifications, check out
this guide here (https://adafru.it/s8f) that'll show you how! Spoiler alert: you'll need to make a small, 22Khz (or lower), 16
bit PCM, mono .wav file!
There's tons of software that can generate OGG or WAV, we used this service and it worked very nicely without
needing to install any software: http://audio.online-convert.com/convert-to-ogg (https://adafru.it/e0q)
If you don't mind installing software, Audacity can do a lot of conversion and is free software. (https://adafru.it/e0r)
Generating audio files, especially if you want to keep them small, can take a little experimentation: higher bit rates and
sample rates will sound 'better' but take more space. You can go with 44.1KHz sample rate which is basically audio CD
quality, or down to maybe 8KHz for spoken word or low-rez effects.
Another way you can save space is to convert stereo files to mono. The decoder supports stereo but if you only have a
single speaker it doesn't matter if you have stereo output and stereo takes 2x as much space!
Use 8 or 16 bit rates for WAV, 24-bit does not apparently work