Doc and Chico both have high pitched voices. Listening to them commentate together was painful sometimes. We need some low end (which is why I was such a big fan of Gary Thorne).
I cannot imagine in what world you think Gary Thorne is a good announcer. I swear if Joe Sakic, Ray Bourque, Patrik Roy or Mario Lemieux ever came to a sudden stop his face would be halfway up their asses.
Doc did have a high pitched voice but he did work on it over the years and it got a lot easier to listen to. You can def hear the difference when you hear him now and from a mid 90's game.