What we are talking about is "matrix multichannel". With most any surround decoding system, Dolby, DTS, etc. signal that is out of phase between the two channels goes to the rear speakers. This is very damatic if you play a Test rrecording that has material recorded inphase, and out-of-phase for phasing check purposes.
The effectiveness when playing music depends entirely on how the particular recording was mixed. Some stereo recordings that were never intended for multichannel playback are, by accident, dramatic. Most don't work very well. There is no way to tell except to try them.
The effectiveness when playing music depends entirely on how the particular recording was mixed. Some stereo recordings that were never intended for multichannel playback are, by accident, dramatic. Most don't work very well. There is no way to tell except to try them.