A while ago on another thread, somebody mentioned that when listening to 5.1 material just with the front speakers, the surround track are redirected to the mains.
Yesterday, I was listening to the Police Certifiable concert on Blu ray. There is 2 audio tracks on this BD. 2ch True HD and 5.1 True HD. So I decided to disable the center and compare the 2 tracks playing only with the mains assuming that they would sound the same since all the channels that don't have speakers connected to them should be redirected to the fronts. Well they sound completely different. It looks like when selecting 5.1, the fronts only play whatever they're supposed to play in a 5.1 setup regardless of the other speakers being connected or not.
A simple example is when a listen to the 2 ch track, I hear the crowd screaming. When I listen to the 5.1 track with my 3.0 system I don't. In this particular case, the 2.0 track sounds better than the 5.1 since I don't have surrounds.
Any thoughts?

I'm using a 3.1, but I have my BD player set to virtual surround, which I'm assuming means that the surrounds are forced to play out of the mains. Since I don't have surround speakers, I can't do any comparison.

Hi Bruno,

Whoever told you that the surround tracks are mixed back into the front channels if you leave the system in 5.1 mode is wrong, as you discovered when you listened to the front speakers but left the playback in 5.1 mode.

You have to select a stereo mode or similar (Stereo Mix) in order to preserve the information that would normally be routed to the surround channels and the center.

Regards,
Alan

OK, so it looks like I misunderstood the info given on another thread. The info was about the center channel, when disabled, the fronts would play the center track acting as a phantom channel. Is this correct? I guess I just assumed that it would apply for the surround track as well.
So now, no movie includes stereo track anymore, only multichannel. Does it mean that until I get surrounds, I will never be able to hear everything?

If you go into the Disc Setup menu when you play back a movie DVD, there should be an option for "Stereo" or "Surround" (or Dolby Surround).

All DVDs contain a stereo mix as well as a 5.1 mix but you have to select the Stereo mode. It might be labeled "2.0" (no subwoofer) or 2.1 (Stereo with subwoofer).

In that mode the center and surround information is all down-mixed (blended) into two channels with the left and right main channels.

Thanks Alan.

Bruno, just to be sure that when you say "disabled" you don't mean that you just disconnected the wire. If that's done, the signals are still sent toward that speaker, of course, but aren't played. The center speaker has to be set to "none" in the setup menu for the mains to receive those signals.

John, I meant disabled on the receiver (aka set to none).

So if I understand correctly, if I'm listening to a 5.1 material with only the FR and FL enabled and all other speakers set to none, my mains will play the L/R and C tracks (since I hear the dialog) but not the surround tracks? Is that correct?

Yes, the previous posts that you were recalling had to do with employing a "phantom" center with a 4.1 or 4.0 speaker setup. There's no special 4-channel or "phantom" setting to be made; by setting the sub "none" the .1 channel is automatically directed to the mains and by setting the center to "none", the center channel signals are automatically directed to the mains. The situation is different with regard to "down-mixing" 5.1 material to stereo. The player has to be set to whatever the particular manual calls it, as Alan mentioned, for the down-mixing to take place.

One thing, even if you do find the down-mix controls in either your player or receiver, you won't even get the .1 content from DVDs/BDs on a .0 system. The down-mix rules say to not send the LFE (Low Frequency Effects) to any speaker other than a sub-woofer.

Luckily, other rules also say to not mix any musical content as LFE, only effects. -- Not everyone follows that second rule though.