My builder wouldn't do as I'd asked, to add gauge metal "Z" shaped furring strips between bottom of joists and drywall, so now I have a direct connection from my ceiling to the floor above (even with 12 inches of fiberglass insulation). My best option now is to add a 2nd layer of drywall with "Green Glue" (construction adhesive) in between the layers.
Other tips:
Follow the Cardas formulas for room proportions to minimize standing waves in the room. This one is huge (sound treatments aren't needed in my place with Cardas speaker/listener nearfield recommendations).
Have the last run of ductwork into the room be lined/insulated flexible duct to absorb sound from the furnace (I can't hear my furnace from inside the room).
Don't install recessed ceiling mounted cans (use wall hung sconces instead) to avoid sound transmission.
Use an insulated fiberglass pre-hung exterior door to the room that has a weather seal. They have a pre-molded wood grain and can be stained/painted later. Really cuts down on the sound transmission through the wall and will be prepped to add a dead bolt lock (to protect your stuff and your privacy).
Try to install staggered stud walls where your room will adjoin other living spaces. I used 2x6 top and bottom plates with two sets of 2x4 studs. One set is flush with each edge of the 2x6 plates and spaced at standard 16 inches centers. The other set is flush with the opposite edge of the 2x6 plates and spaced the same, but 8 inches off from the first, so no solid (sound transmitting material) is in the wall (except at door frames and the top/bottom plates). Then install fiberglass batt insulation. For even better walls use 2x8 plates with 2x6 studs, randomize the spacing (12 - 24 inches, but stagger with the other set of studs), and use 5/8 inch drywall.
All this can be done for less than the cost of your next equipment upgrade, yet it will pay huge dividends. Even with recessed cans and directly attached ceiling drywall, it tooks weeks for me to get used to how spooky quiet my room is.