Soundproofing a room to prevent sound from disturbing neighbors?

No hope, no matter what you do - for those infra-sonics anyway.
A Mackie Thump definitely won't produce any infrasonics. It will do fairly loud bass though.
I have a room within a room, double layer 15mm plasterboard with cld between and 8" of Rockwool behind and can still hear the low end of larger vehicles going past. That said, I can watch films at quite high levels without upsetting the neighbours!
 
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