Hueske, I think you are right but also that a solid door even if gasketed will much satisfy someone in the next room. I think his only real answer is to find another room.
soundproof a door
My listening room has a hollow body bi-fold door that I can't replace with a swing door. My door opens into the living room where my wife watches TV. She frequently complains that my music is too loud. What can I do to deaden that door without hanging drapes or some other lousy attempt? I'm stumped. Frankly, I'm surprised this isn't more of a problem for you all.