Hiya guys and girls, just wanted to clear somethings up for you all. Soundproofing professionally isn't really that much its not going to cost a bomb. But buying low density foam or foam that is a thermal insulation material is going to do f@@$ all for your soundproofing.
In Sing there are lots of people selling foam claiming is for soundproofing but in fact its actually thermal foam or pc packing foam and NOT acoustic or sound absorbing foam.
The best foam i found is the NoiseBlock 3d foam and i used it myself it looks like pyrimid style and its been great for me, but i still had to soundproof my walls with typical gymsum and rockwool.
I used the proper stuff again noiseblock stuff 200kg rockwool and a noise resistant gypsum board, the results have worked for me so thats what i would do.
Double door is good but you need to carpet the back of the door either that or you then have to pay 1900+ for a propper door