Soundproofing

I'd like to do this economically. My plan is to build a room within a room. I want to fill the ceiling joists with acoustic insulation available at Home Depot and then drywall over top (2 ply if needed.)

Then I will put in a drop ceiling leaving a gap between. For the side walls I plan to use the same type of insulation then drywall overtop then leave a gap and put in another drywall all the way around with staggered studs.

I realize this won't be perfect but do you think I can get about a 50% reduction in noise upstairs? If so then I'm happy.

Should this plan be changed somehow in order to obtain my 50% noise reduction goal?

Thanks for the encourgement Max.

Krell man how did you fix your air vent problem and what was the end result like when it was all finished?

Thanks for the tip Larry