After getting these new Mammoth Fold lights hung I am losing about 12 inches off a 7' ceiling. From floor to LEDs is 5'11" (180cm). Then I have stands and trays to think about with my current prototype stand being at 12" for a usable height of around 4' 11" (150cm). Specs are:
12 inch is a bit close. But you can get away with it. Just be sure to keep the surface temps down via airflow and ventilation. You want to be around 18 inches. But 12 isnt bad. I get about 10 away from my 301's sometimes with no ill effects.