Wow, you have a number of options. First, are you sure that 7'-1" is legal for occupancy? I thought 7'-6" is minimum except for small obstructions. I have found in many tight situations I found sprinklers are actually easier than fire resistive construction. You don't mention whether you want the acoustic ceiling for separation/noise transfer or just dampening the basement room. I have found Ecophon material available for glue up installation and it can be cut to fit between the joists. If you are trying to separate the floors acoustically it is much more difficult without mass or multiple layers of dense material. If you are redoing the church as well it may be easier to put the acoustic separation below the finish floor for the church.
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Stewart Brecher AIA
Stewart Brecher Architects
Bar Harbor ME
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