The best sound you can get is by using an uncompressed version of the audio.
The problem is that an uncompressed WAV file, for example, is heavy.
One minute of WAV audio file in 44kHz, 16bit will be 10MB.
A standard game music loop lasts 60-90 seconds, and that brings you to 15Mb for each music loop.
Usually, in small apps and games, the audio is converted to MP3 or OGG formats with different bit rates. The lower the bit rate and sample rate, the smaller the music file becomes, and the quality downgrades as well.
In this post, I’ll show you the differences in sound quality and file sizes between various MP3 and OGG file encodings.
Here’s an uncompressed version of the tune “Sunny Island Pirates” in WAV format, 44khz, 16bit, 5.04MB
Let’s start with MP3. the best bit rate you can get with mp3 is – 320kbps. There will be almost no audible difference between the WAV file and MP3 in 320k (unless you compare between the two using studio quality headphones, or professional studio monitors)
MP3 320kb, 44khz, 16bit, 1.14MB
MP3 192kb, 44khz, 16bit, 703kB
MP3 128kb, 44khz, 16bit, 468kB
MP3 96kb, 44khz, 16bit, 351kB
MP3 64kb, 44khz, 16bit, 234kB
MP3 32kb, 44khz, 16bit, 117kB
As you can hear, the serious damage to the quality happens below 128k. It’s especially audible in the higher percussion sounds. 32k sounds unusable. While MP3 is a good option to downsize the sound it’s not suitable for looping (will be discussed in a different post) and there are other options like OGG Vorbis, which might be considered as a better, but less common format. Here are 3 different quality comparisons for OGG files from high to low. The files size are bigger, but the sound quality is slightly better. And OGG format is perfect for music loops.
OGG quality 1.0, file size 1.84Mb
OGG quality 0.50, 634kB
OGG quality 0.10, 303kB
OGG quality 0.05, 261kB
To sum things up, the smallest file sizes with relatively usable audio quality would be MP3 in 64k and OGG in 0.02.
To get get best results, if you have the option to use larger files, I’d recommend using MP3 128k and OGG 0.5.