Your only, expensive, solution: Lead Wallpaper! Yes, it does exist. Put on the wall and doors. Doors should be overlapped at the cracks. Unless you build a sound proof chamber, like hearing tests are conducted in, every thing else is second best. But remember, the lead paper might lead to toxic posion.
Room Acoustics
Does anybody know the best and cheapest way to sound proof A bedroom in an apartment to aquire better sound from an audio system,etc.It has to be something I can place on the exterior of the walls...Would really appreciate some recommendations here.Ty...Does carpets and egg cartons work?