Sorry for the confusion, I as just was reposing what I have read many times in the dedicated home theater threads. Does not matter which way the sound goes, the process of stopping is the same.
Ted please correct the more important portion of the answer I gave to the question, "what can be done after the fact when the room is completed"? From what I know, without rebuilding the room properly it can be rather difficult and almost as expensive with lesser success to try and fix things afterwards. You obviously are one of the experts on sound proofing and I would appreciate any insight you could provide as I do not like to give bad answers to questions. Adding a second layer of dry wall with green glue on walls and ceiling, sealing all electrical boxes and all air passages, installing mufflers in ac runs and returns etc are effective but without structural isolation (room in a room clips and channels ) the effectiveness is greatly reduced.. Do I have this part correct?
The OP was also asking about "I am looking to see what i can do with minimal impact on the already finished space.
So is the answer "there is little that can be done" a correct answer?