newbie needs help with TV sound connections
I am an AV-ignorant newbie (and old fart) learning as I go so please bear with me. I hope you can help me. I have an older Bose home entertainment system (102EA-II; PN 175461-03) that has only analogue inputs. On my older TV, I was able to connect RCA cables from the TV to the Bose RCA inputs in the wall (connected to a receiver upstairs), and I got sound simultaneously from the TV's speakers and from the Bose speakers in the ceiling behind the sofa. I am not an audiophile and I was completely satisfied.
My TV died and my new Sony Brava KDL-40650D HDTV does not have RCA audio outputs. It has instead an optical audio out, USB, a headphone jack, and 2 HDMI (both of which are in use). I am told by Sony support that I can not get sound simultaneously from the TV speakers and the external Bose speakers. By connecting a Y cable with RCA inputs to the headphone jack, I can at least get sound from the Bose speakers. So that is where I am...but I would still like to also get sound from the TV area, in a sort of poor man's surround, like I had before, if not from the TV speakers directly then from a) two Boston Acoustics speakers that are hooked up to an older (naturally) Sony receiver that has RCA inputs/outputs only or 2) maybe from a more current soundbar (that i do not as yet own). I should mention that the TV is connected to a cable box via HDMI. The cable box additionally has digital optical, USB, and RCA ports. I connected the cable box RCA outputs to my Sony receiver RCA phono inputs and got TV sound from the Boston speakers, but it was out of sync with the sound from the Bose speakers and sounded terrible. (as an aside, I have also tried using a DAC, both from the TV and from the cable box, but maybe because the TV sound is Dolby and not PCM, it hasn't worked - Sony said it "probably" wouldn't work but I tried anyway - best I got was the same out of sync sound.)
So probably a stupid question, but if I continue to use the headphone jack connection to the Bose speakers, would it be possible to also connect the cable box to a soundbar (via a toslink or USB) and thereby also get sound from the TV area? And if so, would that TV-area sound be in sync with the sound from the Bose speakers or would I have the same out of sync situation?
I hope I am being clear enough. I would certainly appreciate any guidance. Thanks.