I installed a Samsung sound bar a few weeks back, definitely different than usual and a pain. Given the way you mount the bar, it does not sit flush against the wall and it leaves about a 1/8" to 1/4" gap from the wall which shows everything.

The power cord is about 6' long and about 8" left of center on the bar.
The optical/mini output sits about 8" right of center on the bar, they come with 6' cables but we used our own.

Given that Samsung gives you a 6' cord and then all of about a 2"x2" space @ the power opening, not much you can do unless you want to mount right under the tv or cut the cord and hardwire the thing inside a junction box but you'd still see the plate.

They look and sound, eh... decent.