I would strongly suggest hiring an acoustical engineer with dual experience in concert halls and garages.
And since you are at the design stage, follow your acoustical consultant advice on the ceiling height. Your DOT maximum height is 14' so when you put your Prevost on the lift, you are going to need at least 24' vertical anyway. Those Prevosts are over 16 tons empty, so plan your lift accordingly. That also helps with the depth of the garage, they require over 45 feet parking depth, so your height, width, and depth approach a normal concert hall or music scoring stage. When in doubt just make it the dimensions of Abbey Road Studio One.
With proper design up front, you could host live music events!
Your functional given is a concrete floor. So you have walls and ceiling to design. Then you can roll out carpet between the bays and place absorbers tuned to frequency. In concert halls today, the seats are selected to have the same acoustics filled with people and empty.
Done right, you could write a paper for the AES, get in all the design and architecture media outlets, and start an acoustic garage consulting business. Forget the Revels, you should probably go pro with the Genelec 8381a mains. Genelec can probably help your acoustical engineer with an ATMOS system, and then you can invite your neighbors to your home theater garage,
Keep us posted, photos or it didn't happen
