Not Samsung, but to get mine to work that way I had to add an audio cable from the TV audio-out to the DVD/sound system audio-in. Then when I turn on the TV, I have to select the appropriate source on the DVD/sound system.
Your Samsung probably has a speaker setup feature somewhere hidden in the menus. If so, it probably also has an individual speaker adjustment feature where you can individually adjust the sound level of each speaker one at a time. If you find that, when you get to the subwoofer, you should be able to find out where the sound is coming from.
Try turning on the TV and the DVD system. Hit the menu button (if it has one) and check all the setup options. Or if all else fails, read the manual. But do that as a last resort.
