It's funny how much time and research is put into the picture on a TV set and then some cheap, poor quality speakers are stuck in at the last minute. To get sound quality that's as good as the picture, you need to hook up some proper speakers. There's no short answer on how to do this, and it really depends on your television and equipment. Hooking up speakers to a television requires a receiver, because the television itself has no speaker terminals and doesn't have the proper amplification to drive a decent pair of speakers.
Route the television audio directly through a stereo receiver. Connect the audio outputs of the television to the audio inputs of the receiver, using digital (coaxial or optical) or RCA (left and right audio) cables. Connect the left and right stereo speakers to the corresponding terminals on the receiver. Be sure that the positive and negative terminals of each speaker and the receiver are correctly lined up.
Use a cable box. If your television doesn't have audio outputs -- many older TVs don't -- use the outputs from a cable box to route your sound to the receiver. Proceed with a digital or RCA connection.
Use a VCR. If you don't have a cable box, run the cable from the wall outlet into your VCR and then instead of outputting the audio to the TV, output it to the receiver so that you'll get sound from cable programming through the receiver and the speakers, rather than from the TV. Connect the video output from the VCR directly to the TV for the easiest setup. You will then need to control your television programming with the VCR.
Change the program mode on the receiver to the input category you used to input the audio. For example, "TV," "Cable" or "Aux" are common options. You should now be able to hear audio from television programs on your speakers.