Novice 5.1 question

[arenson]

I have a SHARP SDPX2 receiver--

http://www.sharpusa.com/files/aud_man_SDPX2.pdf

--actually it was released in Japan by Eclipse/Time Domain 2 years ago, but it is the same player. So no English manual until I found the Sharp one on the Internet.

I am a little confused about the output with certain formats.

For example, on page E38 of the above URL under LISTENING TO 2 CHANNEL STEREO SOUNDS (EXAMPLE DTS), it says you can choose between STEREO or VIRTUAL. I thought they meant that STEREO (two front speakers and sub woofer) is the usual 2 channel sound plus the sub and that VIRTUAL is a kind of fake 5.1 only using the 2 front speakers without the surround.

They are referring to a DTS format disk as an example..


To add to my confusion, there are notes at the bottom which say
"When the surround mode is set to STEREO or VIRTUAL
THE SAME MONOAURAL SOUNDS IS REPRODUCED IN BOTH THE LEFT AND RIGHT CHANNELS.


(1) Ok...now I am really confused, since it says that STEREO and VIRTUAL is really monoaural. Is it a misprint, my poor understanding, or???

And this uses the example of DTS, which I thought was a competing 5.1 format.....

Am I to understand that they are talking about disks encoded in the DTS format played back in 2 or 2.1 (Stereo and VIRTUAL) being actually monaural with some sort of spaciousness added?

OK. And I guess that these same settings with a 2-channel disk will yield STEREO in "STEREO" MODE and "who knows what " in virtual.


(2) So now the next question....if you play a 2 channel stereo disk in Multi, what are you hearing out of 5 speakers? PRO LOGIC synthesized 5 channel?

Oh well, have a headache. Hope my question is not toooo basic.

(3) By the way, which is more advanced...DTS or Dolby Digital?

(4) By the way again, the rear speakers never sound as loud or
as stereo as the front. They actually sound good, but it is not as if I can place the sound in all directions. It just sounds more spacoius. Is it true that I should not be aiming for left right front and left right rear to sound as discreet as traditional 2.0 sound?


Thanks!


Paul

 

[agarwalro]

(1) Ok...now I am really confused, since it says that STEREO and VIRTUAL is really monoaural. Is it a misprint, my poor understanding, or???

And this uses the example of DTS, which I thought was a competing 5.1 format.....

Am I to understand that they are talking about disks encoded in the DTS format played back in 2 or 2.1 (Stereo and VIRTUAL) being actually monaural with some sort of spaciousness added?

OK. And I guess that these same settings with a 2-channel disk will yield STEREO in "STEREO" MODE and "who knows what " in virtual.

Stereo cannot by definition be monoaural. So someone smoked crack when they wrote that in the manual. From what I gathered, if you have a 5.1 DTS disc it will downmix it to play 2.1 if you select "Stereo". If you have a 5.1 disc and you select "Virtual" it will apply some processing and play 5.1 audio, but it may not be true to the recording of the individual tracks.

((2) So now the next question....if you play a 2 channel stereo disk in Multi, what are you hearing out of 5 speakers? PRO LOGIC synthesized 5 channel?

Yes. Matrixed surround is the technical term I believe.

((3) By the way, which is more advanced...DTS or Dolby Digital?

Personal preference for the most part.

((4) By the way again, the rear speakers never sound as loud or
as stereo as the front. They actually sound good, but it is not as if I can place the sound in all directions. It just sounds more spacoius. Is it true that I should not be aiming for left right front and left right rear to sound as discreet as traditional 2.0 sound?

The rear speakers are not meant to detract from the main left and right speakers, only add to them to create an envelope of sound. The only way to tell if you are hearing what the producer intended is to calibrate the setup. You will find plenty of articles on that right here on this website.

 

[j_garcia]

I haven't seen a processor that will downmix 5.1 dts to stereo. You can tell your receiver you only have 2 speakers (no center, no surrounds, etc..) and get sound from only 2 speakers, but selecting stereo with a 5.1 dts track should give you no sound at all because the dts processing is not engaged.

It does sound like a misunderstanding or error in the print on stereo vs virtual, etc... With Dolby Prologic (Dolby Surround), the center and surrounds ARE mono, and the signal is essentially stereo with the prologic encoding for the other channels (matrixed). There are a number of DSPs that can expand stereo to a simulated surround - they are all Matrix, meaning the additional channels did not originally exist in the recording, they are "extracted" from the existing information.

Neither DD or DTS is more advanced.

The rear channels in a 5.1 or 6.1 track are discrete, however you are correct - the surround levels are essentially only for ambiance to add spatial cues, and are generally not as loud as the front speakers. Part of making what you hear convincing is to calibrate your speakers to the correct levels at your listening position so the sound is balanced.