It all depends on who is around you.
I am never the one who "sets the tone", per se, but if I recognize that I'm in a section that will pick up a good chant, usually I'll start some or at least be an early adopter when others do. Usually, this happens in the cheap seats.
When I'm in the lower levels and the whole row next to me is in dress shirts with their hair slicked back and they miss 8 minutes per period, nah, I don't bother being proactive.
In Ottawa, I've found the 200's and 300's by far better than the 100's. In Montréal, the 100's are a lot more electric despite being even pricier tickets. Which I always find interesting, because I know people still living who had to wear suits or fancy clothes when they started going to Habs games, and it was a very serious affair. Clearly, that sense of propriety didn't prevent them from being a rabid, engaged, very proactive crowd in the modern era.
It is probably a bit part of why I'm the rare Sens #1, Habs #2 fan. Hard to go to games in Montréal and not fall in love with the experience.