# Playing External Audio Sources via Multi-Speaker Sound

Multi-Speaker Sound enables a streaming connection via Bluetooth® to any number of devices that support the same standard (e.g. GPB 18V‑1 C, GPB 18V‑6 C).

1. Use the SOURCE button to select Multi-Speaker Sound as the audio source.

1. The indicator appears on the display.
2. GPB18V‑3SC: The top line of the multi-function indicator (a) shows <Multi‑Speaker Sound>.

If a Multi-Speaker Stream is available, a connection to this stream is established automatically. While the connection is being established, the indicator flashes. If the connection is successfully established, the indicator lights up continuously.

Start and control playback at the audio source.

The volume between the audio source and the radio will be synchronised (the audio source determines the volume) until the volume is changed on the radio. To restore the volume synchronisation, restart the connection via Multi-Speaker Sound.

1. To restart the connection, select the Multi-Speaker Sound audio source again using the SOURCE button.

If one of the programme memory buttons (5) is pressed during playback of a stream, the radio switches to the station stored in the last radio mode used.