I have recently purchased a KD-55X75WL which I would like to use on the internal speakers when watching day-to-day stuff like The News, but connect via optical out to my old hifi when watching movies or music concerts etc. Unfortunately I find the sound from the internal speakers worse than any other TVs in the house, even though they are basic, small, non-smart TVs. So I went and found the graphic equaliser settings in the Sound settings->Sound customisation menu. All seemed well, but when I change the frequency sliders there seems to be no effect on the sound! I am wondering if most people never try this because they have a soundbar. The software on the TV is up to date. PLEASE can someone else with this or a similar model try this and see if it works for them, or does anyone have any ideas how to make it work?