someLargeNumber = 8^8 decoder = love.sound.newDecoder('sound.ogg', someLargeNumber) sounddata = love.sound.newSoundData(decoder)
is faster than this:
decoder = love.sound.newDecoder('sound.ogg') sounddata = love.sound.newSoundData(decoder)
at least for sounds above some size. For a 2 second Ogg file, it seems to be about 1.2 times as fast, and for a 90 second Ogg file it's about 35 times as fast.
I don't know what to suggest because I don't know what's going on here, but maybe it could do some of sort of "ignore the Decoder's buffer size and load the whole thing as fast as possible" thing?