Basement Ceiling Insulation - up or down?
As far as a facing goes, insulation that supports a sound rating is not faced at all! It is actually a full size center. If your joists are 16" on center, you would think you need a15" batt, which is what normal insulation is. But sound insulation is a true 16" wide. Don't worry about it falling out, friction will hold it up long enough to put drywall up.
You can also take things a step father by using sound board, and RC1 channel as well. I can explain those to you if you wish.
I would suggest insulating the entire basement if you are going to improve the whole basement.
The above material will not be found in your local "Big Box"(you will confuse the heck out of them), you must go to an actual building material dealer. The company I sell for has been selling these items for offices, condos, ect. for years now.
By the way 5/8" will give you a better rating than 1/2".
By the way, forgive my ignorance here, but what is IC? Will my builder know what I am talking about???