I have a 1GW soundbar, which is optically connected to my Toshiba 46" 3D TV in the bedroom. Apart from being able to set each speakers volume separately, I have the following pre-sets: 1) Not named, but a generic " centre " setting which I understand 2) Also unnamed, but throws the sound wider..also understood. 3) similar 4) full wide 5) This one I don't get...It's called Matrix in the manual...sometimes when set in 5.1 surround, it sounds great. other sources DVD / HDD recorder etc. It sounds like somebody shouting in a tunnel...Any ideas?