I have a Bose Lifestyle 50 HTS (circa 2000) and want to play the audio from the tv thru the systems speakers. The Bose unit only has RCA ports - no digital optical audio or HDMI. The tv is an LG LED model 55uj6540 but it only has HDMI and digital optical audio - no RCA ports. Is there some type of splitter that can be purchased to convert to RCA? If so, what is it called? Many thanks.