michael chuaApril 17, 2020Drivers Thiele & Small, HIFI DRIVERSFE85, Fountek, Full Range Fountek FE85 RAW Frequency Response Fountek FE85 Thiele & Small Manufacturer’s Specs Sealed Box=1.5 liters. F3=150Hz Sealed Box=3 liters. F3=145Hz Ported Box=3 liters. F3=75Hz Ported Box=5 liters. F3=65Hz