At first I thought the solution was to install a recessed box behind the panel. Put the media player in the box and run power to the box.

But looking closer it appears the media player is almost as wide as the panel so unless multiple studs are going to be cut no way to put it behind panel. I think that the speakers are part of the media player. How about a shelf installed just below the panel that the media player sits on and hides the cable from the panel to media player.