How is a dual-room/dual-source receiver different than a receiver with "A" and "B" speaker outputs?

There are two main differences. The first is that dual-room/dual-source receivers allow you to send signals from different sources to each room. For example, you can enjoy surround sound from a DVD in your main listening room while a housemate listens to a favorite radio station in the second room. Note that these receivers can only send stereo signals to the second room, not multichannel home theater sound. The second difference is that some dual-room/dual-source receivers do not power a second set of speakers. They feature preamp-level outputs for the second room that require an additional receiver, amplifier, or a set of powered speakers in your remote listening area.  more

There are two main differences. The first is that dual-room/dual-source receivers allow you to send signals from different sources to each room. For example, you can enjoy home theater thrills from a DVD in your main listening room while a housemate listens to a favorite CD in the second room. Note that these receivers can only send stereo signals to the second room, not multichannel home theater sound.  more