The issue I have is the only audio output of the sound bar for this TV is optical and it appears thus far it can only send fixed volume output. AFAIK I have been through all possible settings that pertain the characteristics of this output. I have also contacted LG support and a helpful tech said this is one of the primary reasons he gets calls and there is no simple solution...Yet.
I had used an optical converter to grab the signal and send it to the powered subs RCA inputs. If the TV is at 75% volume, all good because the sub blends in very well.
My next option was to try an HDMI audio extractor and I presume the volume stays linear with the TV's sound bar. What I do not recall is if this audio is mirrored and part of the signal stay with the built in sound-bar or does completely extract.
The only next option I can think of is adding an AVR just to control the subs volume.
