To get audio from your TV to your soundbar or receiver you either need an HDMI cable or an optical cable. Both can work, but for certain types of audio you'll need an HDMI cable. Fortunately, both ...
But don't throw it out just yet ...
Whether you own a desktop PC or a laptop, chances are you're going to need a pair of dedicated PC speakers to experience anything resembling good sound quality outside of using headphones or a gaming ...