Bluetooth connection with Soundbar sytem (LG)

Hello,

my MacBook Pro from 2011 (updated to Mavericks) is not able to connect with my LG soundbar system (2.1 Ch 320W NB3540 Soundbar).

First it appears to be 'connected' and then "Connection failed' appears. The soundbar even seems to shut down as soon as I try to connect my Macbook.

What can I do about this?

FYI: My brothers Macbook (from 2012 or later) is able to connect with the soundbar at once.

Thank you!