Not Dolby Digital ready. Older movies, of course, often have mono soundtracks. Many DVD-Video releases display icons that show the number of audio channels in a soundtrack and the channel configuration.
Some discs provide a variety of soundtracks using different sound modes.
A movie disc, for example, might use 5.1-channel Dolby Digital for its English track, and Dolby Surround for other languages. Dolby Digital Dolby Digital can deliver 5.1-channel sound from DVD discs. While a subwoofer can be helpful in reproducing low bass in general, it is not necessary to have one if one or more of the speakers in the playback system have extended bass response. Without a subwoofer, the LFE channel's bass effects can be directed to those speakers with extended bass.