channels argument for love.sound.newDecoder
ModPlug seems to be unable to probe files for information and get the channel number. This prevents mono wave files to get loaded as mono, because the default modplugdecoder setting is set to 2 channels.
Something to enforce the channels could solve this, like a fourth argument for love.sound.newDecoder:
love.sound.newDecoder( file, buffer, rate, channels )
I admit that it is a cheap solution. ;)