The BLK 4000 is the all-rounder for every intended purpose. With 4 x 100 watts of maximum power and 4 x 50 watts of continuous power at 8 ohms (160/80 watts at 2 ohms), it really does fire up the front and rear speakers. Thanks to Multi-Connectivity, it can handle both low-level outputs, such as the RCA sockets of a head unit, as well as signals from the speaker outputs of a factory radio. A low-level output and a remote-out enable the connection and automatic activation of a further power amplifier for the bass range, such as the BLK 1000. The crossover frequency is adjustable between 25 and 200 Hz, enabling perfect adjustment of the tuning between the subwoofer and the other speakers.