Yeah I have a Roku attached to the Samsung TV, but I prefer not having external devices. There is invariably at least a little bit of latency when moving from the originating device, through the TV, and then into the surround sound system. It's usually slight but still noticeable to me.
Hmm...is
that what causes live TV to be out-of-sync with our Firestick? We've had both YTTV and Hulu Live TV in the last few years and it's the same with both of them. I forget about it because we hardly ever watch anything but football, and the camera is almost never on the guys in the booth, so we can't see them out of sync. I don't have surround-sound, but I do have external speakers hooked up.
If that's the problem, it's odd that YouTube, Hulu (library, not live tv), HBO Max, Netflix, Prime, etc. don't have any lag. It's only the streaming TV services.
Re: the external speaker thing, I unconventionally hooked up nice studio reference monitors to our living room TV. People used to their native TV speakers think our living room TV sound is awesome, but I know that it doesn't compare to good surround-sound or some high-end sound bar stacks when it comes to TV and movies. However: it sounds frickin' amazing playing music, which ultimately is my highest priority, and I use the TV to play music a fair bit, and I'm an audio-dick when it comes to music. Unlike TV/movies, audio recordings are not mastered with surround-sound in mind, and while it's all the same to 85% of the population, I can't not be bugged when listening to music through those systems. The stereo isn't right, the EQ isn't right, the whole thing is off for me. On some nice audio systems you have more control over the sound settings, and oddly, I have none of that with the reference monitors, but yet they sound superb for music, because that's what they're made for....to let the original recording and mixing efforts of the studio engineer come through. YMMV. If I could, I'd install a good surround-sound system in tandem and toggle back and forth depending on whether I'm watching TV or listening to music.