UPDATE!

Bob, et. al.,
The problem doesn't exist using only TV speakers. I've been diverting sound to a ZVOX soundbar via various methods. Turns out no matter what method I use there's a lip sync error. Since the TV speakers are in sync with motion, I decided to turn on both the soundbar and the TV's speakers. Yep, echoooooo. The echo varied with programming, but was almost always there. I will contact Vizio tomorrow about this (I already have a case number). I'm hoping Vizio can at least address the analog audio outputs to match the TV's speakers sound. The ZVOX doesn't have digital inputs sad
Chris