How to play Multiple channels from a audio Device having 8 maximum output using dsp.Audioplayer..

I have a soundcard with 8 max output channels.

>>info=dspAudioDeviceInfo

info = 

15x1 struct array with fields:
    name
    maxInputs
    maxOutputs

>> info(12,1)

ans = 

            name: 'Haut-parleurs (4- USB Multi-Channel Audio Device) (Windows DirectSound)'
       maxInputs: 0
      maxOutputs: 8

The code I`m using to play is as following

   hafr = dsp.AudioFileReader('sig8.wav');
      hap = dsp.AudioPlayer('SampleRate',44100);
      hap.DeviceName='Haut-parleurs (4- USB Multi-Channel Audio Device)';
      while ~isDone(hafr)
         audio = step(hafr);
         step(hap,audio);
      end
      pause(hap.QueueDuration);  % Wait until audio plays to the end
      release(hafr); % close input file, release resources
      release(hap);  % close audio output device, release resources

The output comes from only two channels and all the 8 channels sound is there in those two channels...