Engineering Principle- Front: 2-way closed system- Center: 2-way closed system- Surround: 2-way closed system- Subwoofer: Bandpass systemFrequency response- Front: 120...25.000 Hz- Center: 120...25.000 Hz- Surround: 120...25.000 Hz- Subwoofer: 33...140 Hz (adjustable)Woofer- Front: 2 x 80 mm (3.2''), Aluminum- Center: 2 x 80 mm (3.2''), Aluminum- Surround: 2 x 80 mm (3.2''), Aluminum- Subwoofer: 1 x 200 mm (8''), Aluminum