new control room help with frequencies

Hi, I have a typical ex bedroom now computer recording room where I use cubase and electronic instruments only to record. I have fantastic FOCAL CMS 65 speakers with berillium friggin tweeters ect...all walls are plaster, one side is all glass, I have attached the plan view with dimensions, all in metric. the big rectangle on the left is built in cupboards wood finish. ceiling height is 2.7m i want to mix reasonably loud, and dont need to soundproof for neighbours as we dont have any :lol: I want to treat the room for the best transparent playback sound to mix, currently I think most low frequencies are dissapearing? anyway I cant seem to get any low end happening unless I use extreme eq, so I am looking at buying the TONTINE ACOUSISORB 3 in 100mm thickness put into frames and hung from ceiling and walls, but what about gaps, and how far off walls should they be? i thought 2 x packs might be enough. Q: where should i place and how dow I best install, I own the house so dont mind putting in nails ect... :poke: I am in SYDNEY AUSTRALIA