Texas Attic Update and trap question.

hey everyone. after a busy summer and fall, i've hired my dad to finish the attic drum/listening room/studio. we did 5/8" drywall on RC and sealed all the corners like in rods book. we laid 3/4" MDF down on 1/2" dense burber (sp?) carpet padding (right on the existing 1 1/8th" tongue and groove plywood deck. we left about an 1/8" between each peice of mdf (so it can shift with time) that we'll caulk as we glue and nail the 3/4" white pine hardwood floor to it (not through the padding or deck) we also framed an extra wall on the side going into the house (upstairs hallway) and made a little airlock entry (two solid core doors). i know i could have spent more money and probably really increased my isolation from neighbors and wife but given our budget and desire to save space and not cramp the room too much, i feel like we're doing pretty good. my question today is about the traps for listening position. we framed a four foot high wall on either side and plan to also build a false wall frame about a foot in front of the window (giving me 4" of rockwool and 8" of space). my questions are... 1: would the triangular side bass traps and front wall be "good enough" with four inches of fibrex rockwool stuffed between the studs and the triangular space and 8" of space left alone. should i also fill the space with hangers or something. i can afford the rockwool. hangers wouldn't cost too much more. making all of that into super chunk would probably break the budget. 2: and then where the sides and front wall meet to the right and left of the window, should the rockwool stop to allow space "around the corner" (does that make sense) or just put it all the way back on the sides and let the front wall meet it a foot out. i hope i'm giving enough description of what i want to do here.

sorry i just realized i put this in the wrong forum maybe... feel free to move me if necessary...