A DVD/TV question

I rent and play DVD movies thru my Sony TV. I have no home theater setup; I use only the speakers built into the TV. Problem is the dialog suffers in volume as if the DVD itself is set up for home theater use with a center channel. It's annoying because my wife and I have to crank up the volume to hear dialog that I'm presuming would be coming out of a center channel if I had one. Am I correct in my assumption that the rental DVDs are recorded this way? I experience no problem with normal TV broadcasts. Short of going to a home theater setup, is there an easy solution for my problem?
Before the movie starts, go to main menu and click on setup on the dvd and tell it you are on 2 channel audio not 5.1 channel. That should do it.

I suspected as much, but am technically challenged when it comes to electronics.
Thanks an awful lot - have a great week!
For late night viewing I click on subtitles; it helps in this regard.