Multichannel Audio (Moved from MQA)

May 20, 2017 at 4:32 PM Post #16 of 116
Pinnahertz mentioned they used a sync pulse generator to get the machines to run at a crystal locked speed. That's how film sync worked with Nagras back in the pre-digital days. They would have been most concerned with pitch, not phase, so they would probably slip start them with a start mark and probably lineup beeps (another film sound technique.) In theory, they could stack up as many tracks as they had four track machines with crystal lock. Abbey Road did a lot of film work, so I would bet they had access to as many as they wanted. The only limitation would be that it would all have to be done on the fly- no automation.

Back when I started in the film business, everything was on 35mm mag stripe. Editors would create separate sound reels with start marks for dialogue and effects (at least 2 overlapping rolls of each), a reel of ambiences (sometimes these were loops), and the music would be on a full coat reel that was capable of 3 tracks. So even the simplest film mix had six mag machines and seven tracks to work with. For big budget movies there could be a lot more with multi-tracked music and full coats for stereo ambiences and stereo sound effects. Dub stages would have banks of mag machines all crystal locked and lined up with start marks on the head of the reel. I can see where George Martin got the idea. He wouldn't have sprockets, so he would have had to line up manually each time he did a take and he wouldn't be able to jump around in the reel, but it would be possible.

All of the elements on Beatles sessions were logged and archived. It all survives. By this time they didn't need to be cheap with tape stock or studio time. All of this info is googleable. There have been a lot of articles on the reconstruction of the mixes in the past few months. They're doing several different kinds of mixes... some that reproduce the original mono mix just cleaner, some that open the mono mix up into stereo and make the balances closer to the Beatles' own mix (the original stereo mix was done by assistants), and the 5.1 mix which is intended to be an entirely new approach. Along with the blu-ray is a set of CDs that include outtakes, demos and mix elements broken out so you can hear how it was tracked. There is a hardback book that details the whole story of the sessions too.

I think when you get a blu-ray player you'll find that multichannel music has moved on a bit from the last time you checked it out. Movies tend to be less innovative, but that's to be expected because the sound is designed to reinforce what's on the screen, not create its own perspective. Immersive dimensional sound fields are the direction things are going in music. It's different than the typical front soundstage with reverb in the rears, and it's different than the ping pong approach too. It does takes a very carefully balanced system to pull off immersive sound fields, but there are audiophiles who have upgraded their home theater systems and calibrated them to work well with music as well.
 
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May 21, 2017 at 8:23 AM Post #17 of 116
[1] Pinnahertz mentioned they used a sync pulse generator to get the machines to run at a crystal locked speed. [2] That's how film sync worked with Nagras back in the pre-digital days.
[3] In theory, they could stack up as many tracks as they had four track machines with crystal lock. Abbey Road did a lot of film work, so I would bet they had access to as many as they wanted.
[4] Back when I started in the film business, everything was on 35mm mag stripe. Editors would create separate sound reels with start marks for dialogue and effects (at least 2 overlapping rolls of each), a reel of ambiences (sometimes these were loops), and the music would be on a full coat reel that was capable of 3 tracks.
[5] All of the elements on Beatles sessions were logged and archived. It all survives.
[6] Movies tend to be less innovative, but that's to be expected because the sound is designed to reinforce what's on the screen, not create its own perspective.
[7] Immersive dimensional sound fields are the direction things are going in music.
[8] It's different than the typical front soundstage with reverb in the rears, and it's different than the ping pong approach too. It does takes a very carefully balanced system to pull off immersive sound fields, but there are audiophiles who have upgraded their home theater systems and calibrated them to work well with music as well.

1. That's assuming that the tape recorders had a mechanism to resolve the pilot sync tone and lock their tape speed to it. Which as far as I know machines of the day didn't, and therefore would drift out of sync with each other.
2. Indeed but Nagras had such a mechanism, to record, playback and resolve the pilot sync tone and Nagras were only single track (mono) until the '70s.
3. No, crystal lock on it's own would not have been enough to avoid drift and therefore severe phase issues, they would need a sync signal and a way of resolving it. Accurate/reliable sync between machines came with SMPTE timecode but that wasn't even invented until the late 60's and wouldn't filter down to the music industry until the mid '70's.
4. Back when I started in the film business (mid '90's) they'd already changed to digital dubbers (+ SMPTE timecode), I did see one dub stage with analogue film dubbers, 35mm stripe or full coat but they were 8 track and again, timecode locked. If they did manage to sync two 4 track music recorders together, it would have required some serious jerry rigging and probably wasn't very accurate or reliable and I've no idea how they did it without machines specifically manufactured to do it.
5. No they don't! George Martin specifically told me the drum kit was recorded in mono. There's at least 5 elements to start with which never existed separately and it's pretty much guaranteed there are other elements which likewise do not exist separately, even given a perfect archiving strategy.
6. No, that's completely backwards! Surround sound in movies is typically used to create the sound of the whole 360deg environment, not just the part of the environment shown on the screen. How this is achieved has been far more sophisticated and innovative than anything done in surround music production.
7. That's the direction film has been moving in for over 30 years and achieved brilliantly even before any surround music formats were invented!
8. Again, Your delineation of "immersive dimentional sound" doesn't make any sense to me, can you explain what you mean any better/differently? Sure, there are some people mixing music in surround, with little experience/understanding, who've used it only as a extreme gimmick but how is stereo + surround ambience not immersive (if done well)? Immersive dimensional sound is not a new thing, it's why surround was invented 40+ years ago and has been explored extensively in film ever since. And why would it need a more accurately calibrated system than for home cinema?

G
 
May 21, 2017 at 2:45 PM Post #18 of 116
too many fragmented bits to read. sorry.
 
May 21, 2017 at 10:13 PM Post #19 of 116
too many fragmented bits to read. sorry.
That's a shame, it answered all your issues.

I had no trouble reading it.

Pilot sync placed virtual sprocket holes on analog tape, which then got dubbed to 35mm mag, frame accurate, using a resolver. That technology has no adaptation to synchronizing two analog machines. Sgt. Pepper was too early for crystal sync, but all that did was cut the sync cable between camera and tape recorder, you still needed a resolver and dub to 35mm mag. Again, not applicable. Likely all they did was us a vari-speed (a variable oscillator with a power amp capable of powering a capstan motor) and feed a really accurate 50Hz drive to the capstan motors. It wouldn't sync well for very long, but it may have served the purpose. I actually did this on a 24 track project a lifetime ago where we needed just a couple of extra tracks for an effect during mixdown. Careful start marks on two different decks, and we got sync to happen just long enough for the mix.
 
May 22, 2017 at 3:35 PM Post #20 of 116
That's probably it. I just know what I used to do in film sound back before digital. (mid 1980s).
 
May 24, 2017 at 3:39 AM Post #21 of 116
That's probably it. I just know what I used to do in film sound back before digital. (mid 1980s).

Which is inapplicable because by then (the mid '80s), the film world was using SMPTE timecode to sync, with machines designed for that purpose. BTW, the change to digital made no difference, to sync digital recorders you still needed tape machines with the ability to accept SMPTE timecode, to be able to lock to it and a "striped" timecode track. None of this is applicable to Sgt Pepper though, as SMPTE timecode had not even been invented at that time, as already explained! So while it may have been possible to get some sort of sync for a short period, it wouldn't have been easy, it wouldn't have been very accurate and it wouldn't have been reliable, it would probably have needed almost constant adjustment. If they did manage a rough sort of sync for Sgt Pepper it would have been no more than two machines and probably only for sections of a track, not the entire album and probably it had to be done once, in a single pass, as I would imagine it wouldn't be possible to achieve the same sync over numerous passes, which by the mid/late '70's was completely routine, in both film and music.

G
 
May 24, 2017 at 12:01 PM Post #22 of 116
I would imagine that they would mix songs on Sgt Pepper one track at a time. Wouldn't you?

In other news, I listened to the new Steven Wilson mix of Jethro Tull's Tales From The Wood last night. I hadn't heard the album since the old vinyl days, and I guess I had misremembered it. I remember it being very folk influenced and acoustic sounding. But the 5.1 mix sounds very prog-rocky with lots of rear channel noodling and goofy 70s style synths. The drums sound very compressed and low in level compared to the rest of the mix, and the bass is soft and fuzzy, not nearly forward enough. There seems to be an accentuation of the high end of the vocals and acoustic guitars, presumably to give it "sparkle". But it ends up making it sound a bit harsh. Other than the sibilants, the vocals sound very present and full though. The album comes with an old quad mix and the original stereo. I'm going to do some comparisons. I suspect that Steven Wilson "progged" it up a bit compared to the original. His stuff always sounds clean and tidy, but I'm not as convinced of his aesthetic choices sometimes. He tends to make everything sound like a Genesis album.
 
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May 24, 2017 at 6:25 PM Post #24 of 116
Sounds like there are seven tracks on some songs. Three bounce downs. They're going back to the original elements used to make the bounce down submixes and rebuilding them in the digital realm. Yep. yep.
 
May 25, 2017 at 1:51 AM Post #25 of 116
I would imagine that they would mix songs on Sgt Pepper one track at a time. Wouldn't you?

No, 4 tracks at a time, they had 4 track recorders, isn't that what this discussion has been about? 1 song at a time with 4 tracks available per song.
[1] Sounds like there are seven tracks on some songs. [2] They're going back to the original elements used to make the bounce down submixes and rebuilding them in the digital realm.

1. Where do they say that? They used no more than 4 tracks according to the article!

2. Were you reading a different article? For "Getting Better" and "Lovely Rita" they recorded the tracks: "guitars, drums, piano, on one 4-track. That’s bounced and laid down to one track on another 4-track. Then they record maybe bass, piano, backing vocals, then that’s bounced again. They then mixed off the third tape." - That's 4 tracks at a time (not 7), bounced down to another tape machine. You do realise that the bounces were not between sync'ed machines? So with the drum kit for example, it was recorded on one track, no separate elements of the drum kit and even to get to that mono drum kit (without the guitars and piano), they'll have to go back two generations of un-sync'ed 4 track tapes! What about the other songs? "A hard day's night" used only 3 tracks with no bounce downs according to the article, so hardly any separate elements are available. There's no mention of any effects and if/how they were incorporated, but everything was done in mono so are most likely baked into the tracks and not available separately. None of this is optimal for creating even a 5.1 mix, let alone an Atmos mix!

G
 
May 25, 2017 at 3:40 PM Post #26 of 116
No, 4 tracks at a time, they had 4 track recorders, isn't that what this discussion has been about? 1 song at a time with 4 tracks available per song.
1. Where do they say that? They used no more than 4 tracks according to the article![/QUOTE]./QUOTE]

I don't think you understand what I'm saying. Maybe I'm not saying it clearly. The probably mixed one track on the album at a time and the article says they did had multiple bounce downs on a single song... four tracks down to one in the first bounce down. Then three more tracks added. Then those four tracks were bounced down to the final mix. That is 4 + 3 tracks. In the new mix they are going back to the original tapes before the bounce downs and assembling them in a multitrack digital mix. 7 elements will give them more flexibility than 4, and digital mixing provides many more options than 60s technology.

On A Hard Day’s Night, said Martin, they used only three tracks of a 4-track machine, but on Pepper, they used multiple 4-track tapes, filling one tape, bouncing tracks down, adding overdubs and bouncing again.

“‘Getting Better’ and ‘Lovely Rita’ have three bounces,” he reported. “They recorded the band, quite often with bass later; it’ll be guitars, drums, piano, on one 4-track. That’s bounced and laid down to one track on another 4-track. Then they record maybe bass, piano, backing vocals, then that’s bounced again.” They then mixed off the third tape.


The set arrives tomorrow, so I'm very interested to hear how the multichannel mix sounds. Martin did a fantastic job with a pastiche of songs on the Love album. It will be nice to hear what he does with a whole album
 
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May 27, 2017 at 12:20 PM Post #27 of 116
I listened to the 5.1 mix of Sgt Pepper last night, and I'm a little disappointed. The sound quality is fantastic- it totally shows how much of a hit the sound quality took with all the bounce downs. But it is VERY conservative in how it lays out the multichannel spread. I can understand following the mono mix for the stereo remix, but following it that closely for the multichannel mix doesn't't take advantage of what multichannel can do. 90% of the mix was front and center, very little rear channel action. There wasn't the technicolor contrasts in ambience like in the Love album. Everything played out with basically the same imaging of the band. I think an opportunity was missed here. In the making of documentary, someone points out that the original mono mix had more of a psychedelic feel than the original stereo one did. That should have been the other way around. And the 5.1 mix should have been even more psychedelic with immersive sound fields and rear channel placement. That didn't happen. I think perhaps Giles Martin was bolder when he had his father to work with. On Love they really explored new ways of mixing. In this one, it seems he was looking backwards to try to slavishly recreate old ways. I haven't listened to the CD mix yet. I'm betting I'll like that one better. The 5.1 mix felt like a stereo mix through big chunks of it.
 
May 27, 2017 at 12:27 PM Post #28 of 116
Kinda what I would expect, given that Love was a completely new work created for a new purpose from original, archival, and new material, whereas Sgt. was a re-work of original material with the goal of being faithful to the original, but taking some advantage of new tech.

I agree, though, I can't see why anyone would think the mono mix was "more psychedelic" than the stereo (or surround) versions, unless of course there were a chemical vector involved.
 
May 27, 2017 at 4:26 PM Post #29 of 116
They were referring to the original mono mix and the original LP stereo mix. The mono mix was the one the Beatles supervised. Assistants did the stereo mix, and it sounded a little crapped out. I can see making the stereo more like the original mono, but if you're doing 5.1, I think it's a mistake not to go all out and use the medium for all it's worth. Especially for songs like Within You Without You, Strawberry Fields, A Day In The Life, etc. Those songs cry out for varied ambiences and surround effects. Mixing them like a jazz combo with a realistic soundstage isn't what was intended when they were doing the original mix. They were trying to create the feeling of surround in mono.
 
May 31, 2017 at 12:01 AM Post #30 of 116
I was critical of the Sgt Pepper 5.1 mix and was ready to mark it off, but I read in an internet forum that the problem was that the front and rear are just out of calibration to each other. I boosted the rear channels +7dB and the mix filled out and became three dimensional. The fox hunt at the end of Good Morning crossed from front right to rear left perfectly. And the vocals were better balanced as well. (They were a little too prominent before.) I suspect that a +3dB boost of the LFE channel is needed too. In any case, the mix I was ready to write off just came to life. I have no idea how imbalances like this can happen, but now that I know, I can correct for it by altering the settings on my amp.
 

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