BeoLab 6000 is probably one of the most famous speakers around today being a part of the standard exhibition at the Museum of Modern Art in New York All 4 woofers have new rubber edges for a new life. They sound perfect again. Since no two loudspeaker units have exactly the same physical characteristics, Bang & Olufsen calibrate them individually to make certain that the sound of each and every loudspeaker leaving our factory is identical. By employing an active electronic crossover network with equalization, we're able to adjust frequencies before they're amplified. The signal from the sound source is shaped before distribution to the separate power amplifiers for bass and treble. Adaptive Bass Linearisation (ABL) is a process patented by B&O and is incorporated in BeoLab loudspeakers. The idea is to use the surplus capacity in amplifiers and driver units, arising by normal listening levels, for a bass extension - a sound reproduction with more bass, than the loudspeaker otherwise would be able to produce. The function is adaptive. This means that the loudspeaker adapts to the signal it receives. Loudspeaker drivers are therefore fully exploited, without suffering mechanical or electronic abuse, and the built in amplifiers are not subjected to signals would otherwise create an overload situation. ABL gives stunning bass reproduction considering the size of the loudspeaker in which it is incorporated. Power consumption: Typical 8 W/stand-by < 1,8 W auto power on system Maximum Sound Pressure Level (stereo, pair) 96 dB Power amplifier modules 2 units, Class AB Long-term maximum output power per module* 59 watts Effective frequency range* 55 - 20,000 Hz Cabinet principle Bass Reflex Magntic shielded Yes Woofer 2 x 9 cm Tweeter 1.8 cm Net volume 3 litres Bass equalizer Adaptive (ABL) 2 power cords are included. Just signs of use on the front covers. Pictures are description Carefully insured shipped