What would be the decibel level for a party with over 50 people?

I might have a party this weekend but I don't want cops at my door. I heard the decibel limit at 10 pm to 7 am on weekends is 50 db. With 4 EPI speakers and two having very nice subwoofers, and probably lots of shouting; am I asking to get into trouble? Also, do underage parties get busted frequently? I want to do this if I can get away with it, but if there's a big chance of me getting in trouble, I'll have to bail out. Thanks.