LG Music Flow NP8340 (H3) Owner's Manual page 23

Connecting 23
6. Select [Next] to complete the connection.
2
,
Note
Speakers may be not connected if the distance
between the speaker (Main) connected by LAN
cable and the speaker (Add) to be connected
is too far. In this case, you can use Music Flow
R1 to extend the range of the signal.