| The others are right, it really depends on what your goals are.
In general, I recommend the following:
Cover the ceiling with some sort of insulation. You don't have a lot of height, so stuffing thick fluffy fiberglass up there isn't really an option. 4" of 703 will work great, though once you get away from corners you can "cheat" a bit to save money: put 2" of 703 spaced 2" down from the wall to get very similar performance. I'd go with the 4" in the corners, preferably spaced down 4" if you can manage it, to increase bass trapping. Alternatively you can use rockwool or Ultratouch cotton. I actually like the cotton for this application because it is easy to remove if you ever move your recording space, it's not harsh to work with like fiberglass or rockwool.
Cover the insulation with cloth, or some soft permeable material to let sound breathe through and be absorbed.
If the room is too dead at this point, you can restore some liveness by adding a thin layer of reflective material, something like posterboard or very thin plastic, around the corner edges of the ceiling. Adding this membrane will restore some high-frequency liveness to the room, as well as possibly increasing your bass trapping a bit. If you do this, I recommend leaving plain absorption above the mix position and prime recording areas (ie, above where the drum kit sits when you record).
Note that there are also acoustic treatment ceiling tiles available; if you can tighten down the drop ceiling so it doesn't rattle so much, and stuff them with acoustic ceiling tiles, that will work too. You could use, for instance, standard Realtraps ceiling tiles around the edges of the room as I describe above, and then the HF versions above the mix position and recording spots. |