playback raw float-32 LPCM audio

playback.js

var xhr = new XMLHttpRequest()
xhr.open('GET', 'path/to/file.mixlair')
xhr.responseType = 'arraybuffer'
xhr.onload = function(){
  var buffer = new Float32Array(xhr.response)
    , ac = new webkitAudioContext()
    , ab = ac.createBuffer(1, buffer.length, 44100)
    , src = ac.createBufferSource()
  ab.getChannelData(0).set(buffer)
  src.buffer = ab
  src.connect(ac.destination)
  src.start(0)
}
xhr.send()