I love doing home improvement stuff like that....except for mudding drywall.
I’ve been told that the secret to building a sound-proof room is to not attach the inside and outside sheets of drywall directly to opposite sides of the same stud. You use 2x6 footer and header and 2x4 studs. You stagger the studs so only every other one is flush with the same side. That way, sound (vibration) can not travel directly from one side, through the stud, and directly to the other. Not sure if it’s true, but seems to make sense from a physics standpoint. I did find a pic of the concept
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