I don't have FSN so I'll watch on NCHC-TV. Tim's broadcast on 96.1 the Fox on IHeart has always run at least a minute behind NCHC-TV on my system.
I stop video on TV at 1st. puck drop. I have my desktop or laptop tuned in to Tim. When he says anything close to puck drop or any action, I start video on TV.
I can usually get within a second of both being in sync. If I miss I have to wait till next stoppage to try again.
Tim talks about syncing it before every game. He needs to be more vocal about first drop to make it easier to sync.