https://www.google.com/search?q=UE48H6400AKXU&ie=utf-8&oe=utf-8

Many HDTVs don't pass more than stereo if the source is HDMI. While some do, why this is remains a bit of a mystery. At first I took it as a reading of HDCP (copy protection) but as Sony regularly passed HD Audio, it can't be that unless it's their gorilla nature to the industry that they dare flaunt the rules.

My bet is some lead at Samsung has ruled it so.