thanks for the advice
sadly this particular TV in question is almost old enough to drink LoL, this is an external device I hook up to it. I will try what you said, and if not it seems like I found one on Amazon that is supposed to work, it's just a bit more expensive than the one I bought, but that's usually how it works, eh?
edit: nvm I'm an idiot, I see the amazon page for the one I bought and it does say it plays SRT files, I am just doing something wrong. Sorry to waste your time!