The basic unit is the LBB 3500/05 it provides control for up to 240 microphone units and supplies power for up to 90 units. It is used for standalone operation only and does not have facilities for a computer interface. It allows microphones to be operated in voice activated and manual modes. There are controls for loudspeaker volume and tone control and also for operation of an automated equalization system to optimize the integrated loudspeakers.