Five screen channel list - help needed

Stefan Scholz · 03-17-2023, 01:58 PM

From the theory, the 5 front speakers are very important channels, more than any other addition, required to cover the largest portion of the theatre hall with stereo coverage in the conductor's perspective.
It pretty much made sense, and that's why it was chosen on Cinerama and Todd AO. The theoretical research of human hearing related transform functions started in the 1930s, and continues until today.
Most point to 5 front, specially in rooms not suited for stereo (e.g. automobile driver seat). De Luxe car stereos these days come with the 5 speakers, some may not be directly noticeable in their install.

With their proposed Atmos layout, Dolby finally acknowledged the theoretical findings, by eventually proposing a 5 channel front, and distributed LFE bass management.

SDDS 8 was chosen for the forementioned research reasons, and to have the showcase option that Todd AO offered. The number of true mixes in the format is not really high, a mixing crew well knowing how to use it, can achieve exceptional results. To just pan the inner channels, or write "0" data ("0" PCM is a valid track, if enclosed in the files), Does not offer extra value and audio quality; but ended in the title number count. Then, theatres with 5 channel capability were mostly those old 70 mm installations, where only a few had sound systems capable of high dynamic range and full frequency response. Many were existing from magnetic stereo pre Dolby NR, again not adding to perceived quality.

Even for me, as being involved with SDDS in the 90's, I have no remembering, which titles actually featured true 5 fronts.
Schwarzenegger Last action hero comes into mind, as one of the very early ones, which might have existed in test only
For sure, MIB Men in Black was 8 channels correctly used, it's been the film we used to make promotional screenings with.
Also Petersen's In the line of the fire and Airforce 1, and The perfect storm had 5 screen used.
Pearl Harbour (adding expanded surround) to the 5 front is a rare exemption from a studio normally not into SDDS. Correctly played, it is extremely intensive and features a perfect mix.

Actually, there were a bigger number of European movies (actually most are teleplays) released in SDDS 8, due to the fact, that extra EU subsidization was granted for using enhanced technology. These films never played 8 channels outside the premiere screenings, the arthouse theatres they played in eventually were glorious mono, or optical SVA at best.

Gordon McLeod · 03-17-2023, 09:06 AM

Originally posted by Andrea Rossi

It's not Dolby's fault the progressive abandon of the 5-screen channel - the motivations you are writing about are indeed true. Even if at 250Hz I would not dare to call them proper subwoofers, the baby boom configuration was a wise use of some speakers that would remain unused otherwise; the Dolby A, then SVA, SR, AC-3, EX; all these helped to improve the theatrical sound.

What I mainly blame it for is the fact their technician forced audio engineers to stuck dialogue in the center only (even if some directors fought against this decision). The reason to "deploy directional dialogue to not confuse the viewers" is nonsense; at the contrary, it's not normal to hear voice from the center of a theater screen when the character who's talking is on the extreme right or left of it, sometimes many feet away, or to hear dialogue stuck there when the character is walking towards one side - that's why Pixar (wisely) chose to use (at least some) directional dialogue, to NOT confuse the kids too much. Was it too difficult to admit that their Dolby MP Matrix had problems with traveling dialogue? (yes, it was, of course, but I digress...)

And also, why using FOUR channels for the surround and only THREE for the screen, is behind my comprehension - where anybody knows that human beings are more accurate at discerning sounds that come from the front, up to one degree of spatial separtion, while much less from the back (and the top); it was not a technical decision too, as Sony was already able to use five screen channels, and two surround - plus a third matrixed one for selected movies, and DCP allowed up to 16 channels... but I guess it was a commercial move. But then Dolby Atmos brought back the LC and RC speakers "en vogue" again... isn't that funny somehow?

The reason for dialogue centre channel only was because of the low seperation of the early Dolby matrix. The pentoptical module was gain riding for +3-3db giving only effecivly 6 db of channel steering. It was not until the use of the tate chips in the 150B did we start seeing logic steering that could actually created single hard channels. The other issue was matrix collapse that happens when in effect all 4 channels are being used at high levels at once and the steering collapses to big mono.
Even in the 60s most 70mm releases only used the 4 track mag mix and Le and Re were either not used or had a just a sum of L+C for LC and Rc was R+C
Tommy definetly didnt use LcRc MegaSound used LcRc for lowfrequency boost much like format 42 but used a eventide clockworks sub bass generator to drive dedicated subs
Sensurround titles did a variety of methods some contained control tracks for a noise generator (earthquake) others had rumble effects only

Andrea Rossi · 03-16-2023, 03:42 PM

It's not Dolby's fault the progressive abandon of the 5-screen channel - the motivations you are writing about are indeed true. Even if at 250Hz I would not dare to call them proper subwoofers, the baby boom configuration was a wise use of some speakers that would remain unused otherwise; the Dolby A, then SVA, SR, AC-3, EX; all these helped to improve the theatrical sound.

What I mainly blame it for is the fact their technician forced audio engineers to stuck dialogue in the center only (even if some directors fought against this decision). The reason to "deploy directional dialogue to not confuse the viewers" is nonsense; at the contrary, it's not normal to hear voice from the center of a theater screen when the character who's talking is on the extreme right or left of it, sometimes many feet away, or to hear dialogue stuck there when the character is walking towards one side - that's why Pixar (wisely) chose to use (at least some) directional dialogue, to NOT confuse the kids too much. Was it too difficult to admit that their Dolby MP Matrix had problems with traveling dialogue? (yes, it was, of course, but I digress...)

And also, why using FOUR channels for the surround and only THREE for the screen, is behind my comprehension - where anybody knows that human beings are more accurate at discerning sounds that come from the front, up to one degree of spatial separtion, while much less from the back (and the top); it was not a technical decision too, as Sony was already able to use five screen channels, and two surround - plus a third matrixed one for selected movies, and DCP allowed up to 16 channels... but I guess it was a commercial move. But then Dolby Atmos brought back the LC and RC speakers "en vogue" again... isn't that funny somehow?

Steve Guttag · 03-16-2023, 01:06 PM

You can blame Dolby if you like but the realities are, the studios already moved away from doing a dedicated 6-track mix and stuck with a 4-track. Screen sizes were shrinking heavily after the mid-60's so the perception was the need for the "Extra" channels wasn't there. There was also a strong move away from panned dialog, which hurt some of the benefits of a true 5-across system since localization of sounds, including dialog is where more speakers shine (witness Dolby ATMOS today).

A spread mix is as one would think where LC and RC are derived via the three real channels, respectively. The audio is "draped" so if one were to pan something across, yes, as it passes over or stays at LC or RC, they are louder...but they are not unique in that their neighbor channels have the same information, at a lower level. If you want to hear an atrocity of a release on 70mm, check out The Bridge on the River Kwai. That feels like a mono mix spread to all five...it was rough to listen to. Talk about the wall of sound.

So, back to Dolby. Do you blame them for offering an alternative use for the tracks? They provided NR to kill the very apparent hiss. They took two, otherwise, unused or poorly used tracks and provided deep bass (subwoofers) for the masses. Before them, you had gimmick formats like Sensurround but with Dolby's LFE channel, one could have it on every title and allow systems that, here to for, couldn't really reproduce very low frequencies the ability, without replacing the entire system to jump into a more modern sounding system.

Again, I'm a 5-across kinda guy...always have been. I love panned dialog and wish it was used to this day (Toy Story did it a bit). but I don't record movies...just show them and set up systems to show them. ALL of my Atmos rooms have 5-across...regardless of screen size. My smallest professional ATMOS room has a screen about 20-feet wide...5-across. Everything just scales down.

Andrea Rossi · 03-16-2023, 11:40 AM

Thanks for your insight, Steve - that's the type of help I need!

About spreads (wasn't that bad habit called "Columbia spread" by the way?):
I'm aware there are some such titles on 6-track and SDDS-8, but, unless the LC/LE and RC/RE are mute (I mean, unless they take the 4-track "as is"), don't they belongs to their respective categories?

Agree that after mid 70s, and in particular after Star Wars (thanks, Dolby!

) only a few titles were effectively 5-screen but I don't know which ones... got no evidences, but only clues, found in this very forum and other forums and websites like in70mm - but sometimes the info are controversials; I usually do not take in account IMDB as most info are wrong there.

Few titles I assumed myself being 5-screen because I read reviews of home media, or memories of theatrical experiences, where they talk about travelling/panning/directional dialogue - a no-no for Dolby, so probably a clue to be non-Dolby hence no baby boom/5.1.

So, back to selected titles:
Brainstorm = ?
Wolfen = Megasound, so no 5-screen!
Superman = Format 43?

About SDDS-8 "upmix":
I read somewhere (in US magazines, years ago, can't recall which ones though) that few 8-channel mixes use full fledged five screen channel potential; yet, also the ones that used the LE/RE sparingly did not make (usually) only spread - a notable exception is Twister (IIRC the director admited it): albeit it's difficult to tell the difference between a (less than stellar) 8-channel and a vanilla 6-channel, unless someone can make a direct A/B comparison - but in that case, how?

Steve Guttag · 03-16-2023, 05:55 AM

I would question all titles after the mid 1970s as to having 5-screen channels. They did happen but were very few and far between and even less so post 1977. For instance, you have Brainstorm listed as 5-screen channels. I don't recall that has an option and I do recall running it. I could see how 5-screen channels, on that title would make it even more cool but I just don't recall it as an option. Even by the late '60s, most 6-track mixes were "spreads" of the 4-track rather than a true dedicated 6-track mix. What is your evidence for most any of the 1980s titles having a 6-track offering? I'd be amazed if a title like Wolfen had a 6-track offering. Other than Annie, I'm not sure any of the titles you have as format 41 were. Superman not only wasn't a conventional 6-track, it was the test film for format 43.

There are people that do keep track of such things, but I'm not one of them. However, I was very active with 70mm releases in the 1980s and beyond and always a proponent of 5-screen channels but there were almost zero releases in formats 40 or 41 after Star Wars (1977), when Dolby and 70mm were heavily tied. Even when SDDS caused a mini-revival of 5-screen channels due to a studio (Columbia/Tri-Star) being owned by Sony, that didn't carry over to the 70mm releases (of which there were very few after the digital audio formats came into being). Even most of the SDDS-8 releases were uninspired and seemingly more akin to the 2D->3D conversions of today in that they were not really mixed that way but were released in SDDS-8 to accommodate the format's viability. There were definitely ground-up 8-channel mixes but I'd say that wasn't the norm...again, like 3D is today.

Five screen channel list - help needed

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Five screen channel list - help needed