-- | Mixes audio files together channel-wise. Can also adjust volumes.
mix' :: (KnownNat r, KnownNat c) => [(Double, Audio r c)] -> Audio r c
mix' []    = silence
mix' :: (KnownNat r, KnownNat c) => [(Double, Audio r c)] -> Audio r c
mix' []    = silence
mix' []    = silence