The audio output of your TV, with adapter, will connect to anything you wish.
You can't just say "my PC speakers" either. What connections does it have?
RCA?
1/8th?
Digital?
1 connection? Or two?
ARC is a feature found in newe(er) TV and audio equipment. IF your HTiB does not have an optical...it probably doesn't have ARC either. I can't download the manual, cause that HTiB is not sold in the US.
So, you need to help us, help you.
Other than the 1 connection from the HTiB into the...
It would help to show a picture of the rear of this Philips. I'm not downloading the manual just to see one picture of the rear.
That TV has an audio output and I assume the Philips does as well. Connect them. I doubt the Philips has ARC.