I'm sure this seems like a stupid question, but I just want to make sure before I buy anything. I'm buying wireless headphones to watch TV and movies cause the walls of my condo are fairly thin. Going with the Sennheiser RS160, but only have an optical jack and RCA out. The optical converter is like 40 bucks, where as an RCA adapter is only a few dollars. I'm just trying to find out what the actual sound quality difference will be and if it's worth the money. Thanks!