Soundproofing Basement Ceiling Question

I'm getting close to the start of my basement mix space and I've got a quick question. Actually my head is overflowing with questions/concerns but this is the only one I can't find an answer for :) I've attached a pictures (I hope it works...). It's what I'm planning for the ceiling. The only problem with this is on the the floor above has hardwood flooring so there's nails coming through the sub floor everywhere. This means I can't put the drywall/green glue right up against the sub floor. I was thinking of putting a layer of 1" rigid Polystyrene board up against the sub floor to even it out. Then put two layers of drywall with green glue in between. I saw post once regarding this but I can't find it for the life of me. Has anyone done this or have any recommendations on this? Any help would be greatly appreciated. Cheers.

Get some snips like this and snip them off. I recommend getting some with extra long grips so you don't have to work too hard squeezing a million times. Also, good lighting is important. Triple check that you haven't missed any! For nails that are too thick to snip off, use an angle grinder. That's what I've done and it works great. Greg

Well that's a simple solution and seems like the best solution. Thanks!