Here's the 55-inch model. Both have speakers mounted on either side of the screen, and like all of LG's Ultra HD TVs, have H.265 HEVC (high efficiency video coding), the successor to H.264. This lets you play back 4K Ultra HD video over USB.
This is the 65-inch LG LA9700. Unlike the cheaper LA9650, which has a fixed speaker grille, the LA9700 has a flexible "sliding speaker" that can slide down from behind the TV to blast you with its 4.1-channel, 50W noise.
Here's the 55-inch version of the LA9700. LG hasn't yet released prices or availability, but all these TVs will soon be on sale in Europe, then with slightly different model numbers elsewhere in the world.