iMac and LG Sound Bar

Hi,

I have a late 2012 iMac 27-inch. I have an LG Sound bar that I want to use with the Mac for watching movies and playing music etc. I have paired the sound bar with the Mac via Bluetooth, it pairs fine and the sound comes through. However, the sound is not in sync with whats on the screen. When I used the sound bar on the tv I was able to access the menu and adjust sync etc either through the TV or the sound bar but the sound bar menu does not come up on the Mac screen when paired (I'm not surprised by this, I didn't expect it to). Any advice on syncing sound on an iMac or how to do it another way? Any help much appreciated!

Rob.