Ac-3 = 5.1? (1 Viewer)

[RaymondK]

I have an older Sony DVD player. It's the DVP-S7000. I'm getting a 5.1 stereo for it. I checked the menu and it only lists PCM or AC-3 Digital. So I'm hoping that the AC3 is for 5.1 sound. Does anyone know more about this or have this player and is getting 5.1 sound?

Thanks,

RK

 

[Vince Maskeeper]

AC-3 is Dolby Digital.

-Vince

 

[Michael Reuben]

To expand on Vince's reply:
"AC-3" is the same as "Dolby Digital" -- but "Dolby Digital" does not automatically equal "5.1". DD/AC-3 can have anywhere from 1 to 6 separate channels of sound.
DD/AC-3 is one of the two official sound formats for DVD, and by far the more common (the other is PCM). All DVD players must be capable of passing the DD/AC-3 signal, however many channels it may happen to contain on a given title. The Sony 7000 is no exception; I still have mine, and it's played 5.1 tracks since day 1.

I'm getting a 5.1 stereo

Sorry to nitpick, but a "5.1 stereo" is a contradiction in terms. "Stereo" means two channels; "5.1", of course, means six.
M.

 

[Harry Lincoln]

I could be wrong, but in the days of laserdisc didn't an ac-3 label on a disc = 5.1 channels, with PCM the preffered format for 2 channel mixes? I have never seen a LD with less than 5.1 channels labelled ac-3.

Harry.

Harry.

 

[Vince Maskeeper]

Harry,

You are correct, but this is more a metter of pref than format dictation. As Michael said, AC-3 is a data format that we now know by the trade name DOLBY DIGITAL.

In the days of laser, it was preferable to use PCM for 2 channel mixes, so AC-3 was exclusively 5.1 on LD... but again this was simply because they had a preferred method for encoding 2 channel material on laser, not because the AC-3 format didn't support it.

So AC-3 is just the file format for DD, and in earlt DVD players (like the one the original poster asked about) they used AC-3 to denote what we now simply call Dolby Digital.

-V

 

[Michael Reuben]

Yes, all of LDs with Dolby Digital tracks had DD 5.1 tracks. That doesn't change anything I said.

DD and LD were an awkward combination developed by Pioneer and Dolby as a way of getting some sort of DD software into the marketplace for the 20 months or so between the introduction of DD and the appearance of a truly digital medium such as DVD. There would have been no point in including a DD 2.0 mix on an LD since, as you note, LD already featured an excellent format for 2-channel digital sound. On DVD, however, DD 2.0 is quite common, and it's also common on digital cable and satellite. All of that comes under the general label of AC-3.

M.