Ceiling / False ceiling question

I have been thinking of doing a last minute change to my ceiling design, before I begin construction. The drop ceiling right now is 13.5', the fire suppression system tops out at 15' feet, and there is about 15' above the fire suppression piping to the roof... 1) Am I correct in my thinking, that I can install acoustic hangers above the drop ceiling? 2) What is the proper means of isolating the ceiling when it is a drop ceiling? My thinking tells me that it would not be possible to fully isolate. The only thing I can think is to take the walls up another 5 feet above the drop ceiling and cap it 5' above the drop ceiling and fire suppression system. What are your thoughts?

i'll try to take a stab here. drop ceilings aren't really any help at all for isolation. hangers above the drop ceiling will still help as far as bass trapping in the ceiling. i'm assuming you're talking about a typical A frame roof? took get more advice you're gonna need more specific details and even some pics. your best bet for isolation is to temporarily remove the drop ceiling, and sheetrock the entire wall up to and including the ceiling using the techniques talked about on this forum and in Rod's book (which it sounds like you need to buy). at this point, it seems like a waste to even reinstall the drop ceiling as it won't help anything and just be a lot of work. you're better off with the full open space too. read this: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=3231 and come back with your full plan and more details. you won't regret the through check through of your plan by the users of this forum.