Dimensions: 100 x 21 x 31.2 cm; weight - 21 kg/each. 8 Ohm nominal impedance, 90 dB/1W/1m efficiency, 40 - 22.000 Hz frequency response. JBL recommends pairing it with amplifiers with a power between 10 and 250 Watts. True 3-way speaker. Bass: 2 6.5 inch (170 mm) woofers, loaded with two different volumes; the low woofer anticipates the roll-off on the high woofer in comparison to the other, and it tuned in a lower frequency, according to a common configuration, but surprisingly difficult to do properly. Both operate up to 800 Hz. A 4.5 inch (120 mm) cone midrange, operating up to 2,800 Hz, a pure titanium 1 inch (25 mm) domed tweeter.