code: function isUnsupportedSafari () {
      var
        isApple = !!( navigator.vendor || '' ).match( /Apple/ ),
        version = navigator.userAgent.match( /Version\/([^ ]*)/ );
      version = version ? parseFloat( version[ 1 ] ) : 0;
      return isApple && version <= 6;
    }
docs: Browser detection is lame, but Safari 6 has Web Audio API, but does not support processing audio from a Media Element Source https://gist.github.com/3265344