Regarding DOWNMIXING with a SACD

[DigiPete]

Quote:

Originally Posted by Wodgy I'd be surprised if there were any players that don't use Pro-logic when downmixing. Without Pro-logic, there is no reason to have a downmix setting at all, since all multichannel SACDs are required to have a separate 2 channel layer.

Well, there is a reason... So you can hear the 5.1 mix on your headphones!
On the Fleetwood Mac rumors DVD-A I believe a guitar which was not on the orginal album release was added back in to the 5.1 mix. Also on some DVD-A and SACDs you get some different tracks on the 5.1 vs the 2.0 layer, like on the Police SACD which has different versions of a certain song on 5.1 vs. the 2.0 layer.

DigiPete

 

[Welly Wu]

To be honest with ya'll: this guy has me so confused about SA-CD that I decided to listen to Red Book CDs exclusively tonight!

 

[AdamCalifornia]

I was not aware of that. Thanks a lot.

Adam

 

[AdamCalifornia]

Quote:

Originally Posted by DigiPete Well, there is a reason... So you can hear the 5.1 mix on your headphones! On the Fleetwood Mac rumors DVD-A I believe a guitar which was not on the orginal album release was added back in to the 5.1 mix. Also on some DVD-A and SACDs you get some different tracks on the 5.1 vs the 2.0 layer, like on the Police SACD which has different versions of a certain song on 5.1 vs. the 2.0 layer. DigiPete

This is a very good one. ... the guitar was added back in the 5.1 mix.
I like it.

Adam

 

[soundboy]

While "Dark Side of the Moon", when originally released, was a bit before my time, I am certain the original recording was done on multi-track recorders....yes, perhaps as many as 24 to 32 tracks. The multi-track recordings get mixed down (by Alan Parsons) to 2 channel stereo because that was the dominant playback format of that time. You should know that DSotM was also available on vinyl records mixed in quad (4 channels).

When DSotM was being readied for SACD, the original studio tapes were used for remastering and remixing to both 2 channel and 5.1 multi-channel SACD. Each of these mixes, the 2 channel and the multi-channel, are distinct and separate from each other, which is how it is represented on the DSD layer of the SACD. I've heard that the mix on the CD layer doesn't sound as good as previous CD versions, but I can't confirm that since the SACD was my first DSotM disc.

If you want to read more about "Dark Side of the Moon" on SACD, check out the below links at highfidelityreview.com....

http://www.highfidelityreview.com/ne...umber=16865731

http://www.highfidelityreview.com/ne...umber=15184533

http://www.highfidelityreview.com/ne...umber=15589155

http://www.highfidelityreview.com/ne...umber=14605367

SACD doesn't involve anything with Dolby; Dolby is one of the backers of the rival DVD-A format. If any downmixing is done with multi-channel section of a SACD, that's done by the player itself....and the result will vary from player to player (assuming other SACD players also can downmixing multi-channel section of a SACD).

As for CD, I don't think we have reached the technical limits of CD playback yet. CD can sound excellent. Both SACD and CD are mere formats....SACD has better potentials than CD, but that's not a guarantee that any SACD will sound better than a CD.

 

[bigshot]

Many of the Rolling Stones SACDs are remixed. If you compare the original CD release of Street Fighting Man to the version on the SACD, you'll find that the track has completely different EQ and reverb. If you didn't grow up with this recording, you might not notice it, but to us old timers, it's a deal breaker. Nowhere on the packaging does it reveal which tracks have been remixed and which ones haven't.

Caveat Emptor!

The two track redbook version of DSOtM on the SACD is exactly the same as the 2 track SACD version, and it sounds exactly like my old vinyl MFSL box. I would notice it if they remixed it. I imagine by definition, the multi-channel version is remixed. I've been told that the MC SACD is different than the old quad release.

I have done extensive testing on excellent equipment, and I can't hear the difference between the 2 channel SACD layer and the redbook layer on my SACDs. The improvements I have noticed are all due to improved mastering, not the format itself.

See ya
Steve

 

[AdamCalifornia]

This post was exactly like the one which follows, except for a few mispellings.

 

[AdamCalifornia]

Thanks! Excellent!
Unfortunately in my recent lengthy post I touched the "mixing" topic,which I do not know,and perhaps which is a divergence from this thread called: "DOWNMIXING". I that like your comment about "up to 32 tracks" for the "Dark Side of the Moon" and the links. They had a great deal of freedom to choose from, to mix in. I also like the stuff about the Rolling Stones. So you can "JOGGLE" the tracks to get the master copy.

On another matter, I was never identifying "downmixing" as SACD feature. It's done the player according to some Dolby stuff. The way I "connected" it with the SACD technology is because this downmixing occurs DURING playing a SACD disc (and also DVD-Audio) and it is downmixing FROM the Multi-ch SACD Area. It would also OCCUR, while playing DTS discs, on my Pioneer DV-578A, accordiding to the manual on page 39. The questions "regarding downmixing" were:
1. What is "DOWNMIXING" FOR, IF you have a "2 channel SACD" layer right there on the SACD disc.
2. Does "DOWNMIXING" performed by a dvd/cd player provide better quality sound than the the "2 channel SACD"?

Some said, higher-end players perform "downmixing" (ON the FLY) via NEWER version of Dolby Surround system and of course then would be better circuitry for the playback,...

We have had a related question: Does the "DOWNMIXING from 5.1 SACD to 2.0" exist at all???? (I know you asked this question.) How could we talk about something which does NOT exist? -ha,ha, ...)

DIGRESSION about MIXING:
Anyway, I browsed through some books guiding through the process leading to creating a master tape (recording multi tracks, overdubbing, mixing in, mastering). It's very interesting. I have a question:
Can you use use just TWO tracks to create, say 5.1?
To create 2.1 is rather straight forward, I guess: one track corresponds to one channel. If those 2 tracks are recorded in such a way that microphones
(or,say electric guitars,or any electric instruments) are located strategically in a studio in such a way that they give a "nice and natural stereo image" then the "2.1" version would be very fine.
For example if two mics where, say just ONE foot from each other,this would be a very poor choice for recording a band with, say with 4 players.
But, on the other hand, if those those two mics were located "under the open hood" of a piano next to strings (not too close to strings and not too far away), and say 1 (2 or 3 feet?) apart this would be OK for the "2.1".
This might still require some mixing-balancing and fine-tuning.
Making 5.1 is borrowing from TWO sound sources (tracks) to output it through 6 channels. This would require a lot of mixing-balancing.
I guess it's doable but the final "5.1" would NOT be good at all.
Having recorded 3 or 4 tracks would help a bit.
Having 5 tracks would be rather natural (assuming nice strategic locations of mics)- one-to-one corespondence between track and output channel.
But having... 32 tracks ... then you could create 32.1!!! ha, ha,ha,...

I am asking this question because of the following label on a SACD disc:
"These were ORIGINALLY two-track and three-track STEREO recordings;
in SACD surround mode,the music will be heard only from the front L and R channels (two-track) and from front R, L,and Center channels (three-track)"

Why couldn't they fiddle around with "mixing-balancing" to get some decent APPROXIMATION of "5.1"? Or, the tracks were recorded by getting input from BADLY strategically located mics??? Say, 3 mics were in front of the performers (I guess piano and violin) close to each other and thus giving no contribution to 3D imaging. (I gues this was done in 1940s)

Adam

 

[ken36]

Outstanding thread. Very informative. Thanks.

 

[soundboy]

Quote:

Originally Posted by AdamCalifornia I am asking this question because of the following label on a SACD disc: "These were ORIGINALLY two-track and three-track STEREO recordings; in SACD surround mode,the music will be heard only from the front L and R channels (two-track) and from front R, L,and Center channels (three-track)" Why couldn't they fiddle around with "mixing-balancing" to get some decent APPROXIMATION of "5.1"? Adam

Sounds like you are talking about the BMG/RCA Living Stereo SACDs.

If you are talking about those SACDs, some of them were indeed recorded in 3 channels (left, center, and right). However, due to the playback technology of the time, these recordings were limited to 2 channels and they were remixed from 3 channels to 2 channel stereo. With SACDs, the original intent of the recordings can be realized by the multi-channel capability of the format. Since SACD requires a dedicated 2 channel stereo mix, these Living Stereo SACDs offers the original 2 channel stereo mix and the 3 channel multi-channel mix as original recordings intended.

Since Dolby Pro-Logic was mentioned in this thread, there's a Dolby 3 mode that came with Dolby Pro-Logic. Basically, Dolby 3 artificially generate a center channal signal from the information provided by the stereo left and right channels. I am not sure whether this particular implementation of "multi-channel" made it to Dolby Pro-Logic II or IIx though.

I am sure the engineers can "create" a 5.1 surround mix from just about any stereo recording. However, will that be faithful to the original master tapes or the original recording's intents? There are many, including myself, that rather have good 2 channel stereo performance instead of lousy 5.1 surround sound performance.

 

[AdamCalifornia]

Hi SoundBoy!

Yes, this is the Living Stereo SACD.
(BTW, how to delete the earlier version of my last "double"-post. They differ by 2 or 3 mispellings???)

So, as I suspected, there was NOT enough tracks to work with to create the muti-channel 5.1 SACD version of the sound. In other words, the "5.1" sound requires more DATA to describe than pure "2-channel" stereo sound. The engineers would need to ARTIFICIALLY and ARBITRARILLY CREATE the
6-channel sound. ARBITRARILLY, because who cares if they produced the 5.1 sound where you'd hear violin playing 10" (inches) farther to the left than it was in real life during the recording session. They would use special effects like "delays", "reverbarations", and some proprietary tricks, which we'll never know about. All this is naturally intuitive and logical! ...
BUT I am not quite at home yet because of:

Quote:

Originally Posted by soundboy If you are talking about those SACDs, some of them were indeed recorded in 3 channels (left, center, and right). However, due to the playback technology of the time, these recordings were limited to 2 channels and they were remixed from 3 channels to 2 channel stereo. With SACDs, the original intent of the recordings can be realized by the multi-channel capability of the format. Since SACD requires a dedicated 2 channel stereo mix, these Living Stereo SACDs offers the original 2 channel stereo mix and the 3 channel multi-channel mix as original recordings intended.

Why "dedicated 2 channel stereo mix"? Don't they start from the scratch (using only multi-tracks) to produce the "5.1" sound? As You said in the previous post, that in the case of the "Dark Side of the Moon" they created SACD 2.1 and SACD 5.1 INDEPENDENTLY!? So it means they did NOT use the "2-CHANNEL" stereo mix. Perhaps there are several approaches here. I am not considering recording in "5.1" now, but using recordings stored on OLD analog tapes created, say before 1975. Definitely, I am missing something here.
Actually, how many tracks, ON AVERAGE PER SONG, they used to create the album. If they used only, say 27 tracks for the whole album, it means they used on average only 3 tracks (27/9 = 3), per SONG. And 3 tracks per song would mean that we have the same situation as with the Living Stereo SACD.

Here is my understanding of creating a MULTI-CHANNEL sound.
Let's assume that we produce just ONE song.
The sequence in the production of a MASTER TAPE is:

recording many tracks (say 10)==> overdubbing ==> mixing ==> mastering

(Here the word "mastering" is used improperly, but let's apply it just one song.)

Now let's assume that the MASTER tape is recorded on an (physically) ANALOG (reel) tape (which is still preferred medium among the "producers").

So the MASTER tape contains:
(a) 10 SEPARATE tracks
(b) a whole song obtained by mixing-in the separate tracks
(perhaps not all the tracks were used, ..)

Assume that this master tape (analog) was created in 1973.

WHAT kind of "sound" could one get from the tape?
Well, the answer is: depends on what you want.
Do you want MONO, STEREO, 3-channel, 4-channel (quadrofonia), or "5.1"
(or 6.1, 7.1, 8.1, ...). Is it possible?

Now "5.1" in what format/encoding/decoding? SACD, DVD-Audio, DTS (CD)?

I imagine, that we need a special tool called "black box" (processor) which would TRANSFORM the sound from the analog tape into "multi-channel" sound stored in SOME FORM on a modern type media (computer disc, optical, ..).
Notice that the song is given IMPLICITLY by 10 tracks and this is the DATA the "black box" would be working on. (I dot know whether the "black box" would also need the whole sond stored explicitly on the analog tape.) We have 10 degrees of freedom while MANIPULATING those 10 tracks in such a way to get the "5.1" sound. The "black box" (processor) is reading those 10 tracks (it means it is reading IMPLICITLY the "whole" song). Then an engineer using the console of the "black box" and joggling around with the tracks and utilising any acoustic tricks produces, say MONO, STEREO, 3.1, 4.1, or 5.1 sound, which is DIGITALLY ENCODED and stored on some modern medium. ("Digitally" because of 0s and 1s.)

General idea would be:

analog master tape ==> BLACK BOX ==> multi-channel digitally ENCODED sound on some medium

This ENCODING MUST BE SPECIFIC, i.e. SACD, DVD-Audio, ..., in order to be IMPLEMETED.

Now let's focus on "5.1" discrete sound and consider only the SACD encoding/format, i.e Sony DSD system. So, in this case, this "black box" (advanced electronical unit) is called: "Sony DSD black box" (or more probably Sony DSD processor).

We have created:

"a DIGITAL REPRESENTATION ENCODED according to Sony's DSD" system-format (stored on some optical medium) of an original song stored on an analog tape (medium)"

This is the FIRST DIGITAL MASTER copy of the ORIGINAL ANALOG MASTER copy on an analog tape.

Where could one read about this stuff?

Adam

 

[bigshot]

The Living Stereo recordings we were talking about were made in the fifties, when four track tape decks were the state of the art. By 1970, four tracks were replaced by 24 tracks. Most of the albums released on SACD would be on 24 track two inch tapes.

Two of the tracks on the 24 track would be the stereo mixdown. That's what would be used to create the 2 channel SACD. To create the 5.1 tracks, an entirely new mix would have to be created, going back to the individual elements on the 24 track, rebalancing them and recreating any reverbs or effects. Unfortunately, this almost NEVER results in a mix that compares to the original 2 channel mix. Very few mixing stages have the ability to create slapback reverbs (tape feedback loops), wire reverbs (an early form of artificial reverb) or natural reverbs (echo chambers with a speaker at one end and a microphone at the other). Digital reverbs can never reproduce the sound of these particular effects. Usually, the mixer will just start from scratch and create his own idea of what the mix should be, without the input of the original artists.

I like stuff created for 5.1 by the artitsts, but I don't like after the fact remixing.

See ya
Steve

 

[AdamCalifornia]

Quote:

Originally Posted by bigshot The two track redbook version of DSOtM on the SACD is exactly the same as the 2 track SACD version, and it sounds exactly like my old vinyl MFSL box. I would notice it if they remixed it. I imagine by definition, the multi-channel version is remixed. I've been told that the MC SACD is different than the old quad release. I have done extensive testing on excellent equipment, and I can't hear the difference between the 2 channel SACD layer and the redbook layer on my SACDs. The improvements I have noticed are all due to improved mastering, not the format itself.

Thanks o lot! You confirmed that the Red Book CD version sounds "the same as" the "2-channel SACD" version. (Technically speaking they are not identical because the "2-ch SACD" has been remastered, but NOT remixed). By mixing we mean that "blending", say 16 tracks, to get the 2 channel version, was NOT done from scratch again.

Since this thread is basically about DOWNMIXING (with some digressions about MIXING, ha, ha, ...) what do you think about the DOWNMIXING from "SACD 5.1" to "2.0" performed ON THE FLY by a DVD/CD or CD player? Is it recommended, while using high-end equipment (better circuitry and newer Dolby surround systems)?
Have YOU ever used it with this or other SACDs?
Recall that we assume that we use a 2-speaker systems (with subwoofer) or just headphones.

Adam

 

[DigiPete]

Quote:

Originally Posted by AdamCalifornia Thanks o lot! You confirmed that the Red Book CD version sounds "the same as" the "2-channel SACD" version. (Technically speaking they are not identical because the "2-ch SACD" has been remastered, but NOT remixed). By mixing we mean that "blending", say 16 tracks, to get the 2 channel version, was NOT done from scratch again. Since this thread is basically about DOWNMIXING (with some digressions about MIXING, ha, ha, ...) what do you think about the DOWNMIXING from "SACD 5.1" to "2.0" performed ON THE FLY by a DVD/CD or CD player? Is it recommended, while using high-end equipment (better circuitry and newer Dolby surround systems)? Have YOU ever used it with this or other SACDs? Recall that we assume that we use a 2-speaker systems (with subwoofer) or just headphones. Adam

I think alot of SACD and DVD-A 2 ch is the original mix just digitized with the new equipment. That's why often the 5.1 sounds different.

My Denon 3910 does it wonderfully for all 5.1 SACD and DVD-A's I own (I don't think any dolby processing is involved). The 578a does a decent job too, although it refuses to downmix some DVD-A's (protected against downmixing?) so you only get the L, R tracks in those few cases.

DigiPete

 

[AdamCalifornia]

Hi Steeve!

Quote:

Originally Posted by bigshot The Living Stereo recordings we were talking about were made in the fifties, when four track tape decks were the state of the art. By 1970, four tracks were replaced by 24 tracks. Most of the albums released on SACD would be on 24 track two inch tapes. Two of the tracks on the 24 track would be the stereo mixdown. That's what would be used to create the 2 channel SACD. To create the 5.1 tracks, an entirely new mix would have to be created, going back to the individual elements on the 24 track, rebalancing them and recreating any reverbs or effects. Unfortunately, this almost NEVER results in a mix that compares to the original 2 channel mix. Very few mixing stages have the ability to create slapback reverbs (tape feedback loops), wire reverbs (an early form of artificial reverb) or natural reverbs (echo chambers with a speaker at one end and a microphone at the other). Digital reverbs can never reproduce the sound of these particular effects. Usually, the mixer will just start from scratch and create his own idea of what the mix should be, without the input of the original artists. I like stuff created for 5.1 by the artitsts, but I don't like after the fact remixing.

Thanks again. I was not certain about the number of tracks (per song) to get the "5.1". Of course this number should be much greater than 5.
Anyway, this is what I've found in the links given by SoundBoy:

"... A unabashed analogue fan Guthrie decided to get as many of the original tapes as possible and mix the entire project on a sixteen-track Studer multi-tracks of the same vintage used used on the original Abbey Road session. ..."

To me it implies 16 tracks. Sorry for being so obsessed with the numbers of tracks used to get the ORIGINAL (1972-1973) and the 5.1 (2003) versions of "The Dark Side of the Moon" respectively. Tonight I'll be watching the DVD "The Making of the Dark Side of the Moon". Then I will know the EXACT number of tracks, ha, ha, ha.

I can see the complexity involved in creating the 5.1 version in ANY format.
It is a creative process involving "arbitrary" ARTISTIC approach.
I've come across a beautifull book entitled "The Art of Mixing".
It's got a lot of interesting illustrations. I've also read that nowdays on an 2-inch tape they can have 256 tracks. They still use the analogue magnetic tapes because of the "warmth" they deliver- however it is perhaps 50-50.

Adam

P.S.
I am also reassured that the DOWNMIXING performed by a cd player alone has NO chance to compete with the MIXING created by the ARTIST engineer with the musicians themselves (Pink Floyd) around him.