LG RU-48SZ40 - Manual (Page 16)

P A G E 1 6
Speaker Connection
EXTERNAL SPEAKER(8 Ω )
(-)R(+) (-)L(+)
Connect the external speakers to TV’s “EXTERNAL SPEAKER” jack.
Be sure to connect the positive “+” wire to the “+” input and
the negative “-” wire to the “–” input.