A:Answer You may want to research what the numbers mean before an after the dot with regards to speaker systems. Not sure what you mean by "expand". LG offers a rear semi-wireless speaker add-on; which is a wireless receiving unit attached to two speakers by wire. More sound? Yes. But, still, a 2.1 system if, IF, if it were really a 2.1 system. In actually, it seems to be an 80W, monaural or one sound channel with a LFE channel system.
If you mean by "expand" can you add more channels to make it a 3.1 or 4.1 system - probably lot. That would depend on the electonics (best known by LG) as such that the soundbar would automatically detect and re-distribute the sound to 3 or 4 channels (left-center-right) or LR-RF-LR-RR.
