Here is the speaker circuit's other end. Here are two electronic relays to switching the 230 V bulbs. When the music is voicing, the bulbs are flashings, for the music's deep voice. Cute flashing to the drums..

The other relay upper the bulbs are voice frequency receiver, which looks the electric network, it gets a central signal, and switch the boilers, and the night (cheaper) power. It is power limiter tool. Here when somebody ask, he get an another electric meter which give the cheaper limited power. The most of houses have two electric meters with this like relay.