In regards to the suggestion of what amounts to a suspended ceiling. You could well make things sound a lot worse in your room taking that route. I strongly second Tom's suggestion of perusing both the book he suggests and another by the same author, The Master Handbook of Acoustics. There are great (affordable) suggestions that should work toward both a better listening environment for you... and a worse one for her!
Sound proofing listening room
My listening room is in the basement. My problem is that my wife above can hear too much, always telling me to turn it down, I was wandering if anybody has any cheap ideas to help keep the music in my basement.I do know the the space between the ceiling and floor are not insulated and I'm planning on doing that. But I'd like to do more. Treatment for the ceiling in my room is ok. Anything is ok cause it is my room to do with what i want. So I welcome all suggestions.