If you own a home theater receiver chances are that you have several DSP's (Digital Sound Processing)to choose from. Titles of these various soundwreckers include Concert, Jazz, Rock, Classical, Hall, Videogame, etc...
Although I prescribe to the theory that you should do whatever sounds best to you, I am giving a strong advisement to turn them OFF.
When a movie is digitized to DVD, the folks at Dolby Labs and DTS are saddled with the responsibility of preserving the sound of the original theatrical release, and making sure that you the end consumer have an experience closest to sitting at the AMC. (Popcorn and 84 oz. Coke in tote.) This must be done because your surround sound system doesn't have 22 speakers and 4 subwoofers like your nearest IMAX. Your system has between 5-7 speakers and 1 subwoofer. The technicians at Dolby and DTS analyze the sound data and assign each squeak, rattle, whisper, hum, explosion, and breath to a particular speaker at a specific time, all for your listening enjoyment.
When you select a DSP you are raping the integrity of the soundtrack. Circuits onboard your receiver employ a basic algorithm to the original data and the amplifiers spit out filth in return. The original data is not only lost, but even deflowered and impurified. I find it hard to believe that your budget $300 receiver will improve the quality of a soundtrack that took months and sometimes millions of dollars to produce. I realize that most of your are doing this unknowingly and may not have it set up properly in the first place, but can't you tell that it sucks?
Many receivers have a few buttons that give our little problem a quick fix. Look for buttons that say something like "direct", "pure direct" or "DSP OFF". These buttons allow only the original data from your dvd to be amplified and thrust into your earlobes as candy is so frequently thrust down my esophagus. And sweet it will be.