Film-Tech Forum ARCHIVE: Is there such a thing as an ENVELOP (overhead or height) channel ?

This is topic Is there such a thing as an ENVELOP (overhead or height) channel ? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=008100

Posted by Alan Gouger (Member # 543) on 06-25-2006, 11:00 AM:

I just picked up a Smart Mod 7a and in the manual it states it has the matrix to decode the ENVELOP (overhead or height) channel in theatres equipped with overhead speakers.

How many movies have this encoded into the sound track or is this hype. I never really heard of this channel before. Is this an extension of EX ?

Thx.

Posted by Frank Angel (Member # 248) on 06-25-2006, 02:48 PM:

Yah, there is such a thing, but besides theoretical testing, I don't think it has ever been used on a commecial release. You see, the real problem they found out when they tried to test this system was that they couldn't find enough test subject who had that all-important third ear growing on top of their heads. [Roll Eyes]

This thing about adding more and more channels has gotten a WAY out of control, IMHO. Sony's 8 channles makes you feel positively sensory challenged when you realize you only have those mere two wimpy ears to hear it all with. How will I ever appreciate all those extra channels?

Enough of my sarcasm....maybe someone else knows if this channel-above-the-head has actually been utilized beyond the "wouldn't-this-be-a-kicker-marketing-hook" stage. And you can be sure someone is already thinking about putting a channel UNDER the seats -- they will call it envelope-up-your-butt-surround. [uhoh]

Posted by Richard Hamilton (Member # 321) on 06-25-2006, 03:34 PM:

Large format films have a discreet overhead channel. On flat screens, it is located above the center channel behind the screen. In domes, it is placed directly above the audience. I have never used a Smart processor for large format, so I don't know if this is what they are referring to.

Posted by Alan Gouger (Member # 543) on 06-25-2006, 03:41 PM:

quote: Frank Angel
And you can be sure someone is already thinking about putting a channel UNDER the seats -- they will call it envelope-up-your-butt-surround.

Thanks Frank. Thats what I figured.

I can see your channel UNDER the seats idea being a hit in rest rooms with little monitors on the door. For 25cents watch a movie while you crap. Those explosion scenes will really help the process along [Smile]

Posted by Brad Miller (Member # 2) on 06-25-2006, 03:46 PM:

quote: Frank Angel
And you can be sure someone is already thinking about putting a channel UNDER the seats -- they will call it envelope-up-your-butt-surround.

It's called subwoofers, and the nice thing is the don't have to be underneath the seating. [Big Grin]

I believe the SA10 had the "overhead" channel output if I'm not mistaken. The "surround" output of that CP45 conversion was to be reserved for overhead audio.

Posted by Steve Guttag (Member # 268) on 06-25-2006, 04:11 PM:

The SA-TEN indeed had the "extra" channel.

Overhead surrounds have been played with throughout surround's life. Some theatres, even set up by Mike Todd used them. The Colonial Williamsburg Visitor's Center's signature film, The Story of a Patriot has been running with ceiling surrounds for almost 50-years now.

I have never heard a ceiling surround system that I thought worked. Speakers tend to beam so when you are under a speaker it is loud and clear...when you are off to the side you are in a dead zone. Now if you took your ceiling grid and placed a speaker, say an Altec 604, behind each one...yeah you could have a kick-ass ceiling speaker effect and perhaps even do some multi-channel surrounds with it. However, you still really need side and rear speakers to pull the sound in the direction you want. I can see ceiling surrounds helping with an effect like a plane going over the audience's head but not for most surround effects.

Posted by Alan Gouger (Member # 543) on 06-25-2006, 05:33 PM:

Would the ceiling channel info come from any sound hitting the center and surround at the same time or is it added as a hard channel.

Posted by Mark Lensenmayer (Member # 134) on 06-25-2006, 10:28 PM:

Ioan Allen is quoted as saying that Dolby tested an overhead channel on WE ARE SOLDIERS in the Phoenix area.

quote:
HR: Speaking of which, how is Dolby's overhead audio testing going?

Allen: We're doing a test in Phoenix where we're running an overhead channel on "We Were Soldiers" which has an extra roof channel. "Soldiers" is a film that had a lot of helicopters flying overhead, so it made sense. In 99.9% of films, there is nothing overhead. Low-flying pterodactyl are pretty rare in real life. The earth is flat so most sounds are horizontal to you. That's why you've got two ears on the sides of your head and not an ear on top. So the two ears on the side of your head are focused on the horizontal plane.

Now if you have a limited amount of channel carrying capacity in any medium, from a telephone, a CD, to a film, you have to say, "Where is the most usage going to be?" So you wouldn't waste, say 50% of all your bits on the ceiling channel which is only going to be used in one movie in a thousand.

So you have to say, "What is the best general purpose allocation of channels for most movies?" That would lead you to believe that the concentration should be on the screen, which is where the story is. And then you say to yourself, "Do you need a height channel behind the screen?" And the answer is, as the pictures get bigger, probably yes. This discussion is ongoing.

Bigger screen means you probably need a height element which might lead you to believe you'd need a loudspeaker at the top of the screen which would serve a lot more purpose in most films than having a loudspeaker -- the 'voice of God' -- right over your head. Also, it's going to be a lot easier to maintain than the one on the ceiling. That doesn't mean you rule-out the 'voice of God' speakers. What you do is you then structure a file system, a carrying pipe that says this could be allocated for certain films to a ceiling channel if the theater is so equipped.

Ioan Allen Quoted in Hollywood Reporter

Posted by Richard Fowler (Member # 893) on 06-26-2006, 08:37 AM:

On the 7A, depending on the selection of CS/OS dip switch and proper amplifier / speaker wiring, will either work in EX surround format or surround / ceiling format for digital sound inputs...the unit has a load of features considering the low price of the system. [Cool]

Posted by Mark J. Marshall (Member # 1409) on 06-26-2006, 02:12 PM:

There are several multiplexes in this area that inadvertantly simulate an overhead channel by having all of their surround speakers in the ceiling. Nothing surrounds you in these theaters. Everything flies over you.

A helicopter that the screen suggests is circling around you actually sounds like its circling above you.

When you're in a forest, instead of surrounding you, all the birds sound like they're right over top of you about to take a crap on your head. I might be prompted to cover my head if the speakers were of a better quality.

I guess someone thought that would sound cool. [Shrug]

Posted by Alan Gouger (Member # 543) on 06-26-2006, 02:19 PM:

Mark

Thats a different approach that sounds like for somethings would work very well while for others it would not [Smile]

Posted by Frank Angel (Member # 248) on 06-26-2006, 04:46 PM:

quote:
The earth is flat so most sounds are horizontal to you. That's why you've got two ears on the sides of your head and not an ear on top.

What did I tell you. [Big Grin]

Posted by Joe Redifer (Member # 3) on 06-26-2006, 07:33 PM:

quote: Ioan Allen
The earth is flat

I expect no less from a guy with a silent "o" in the name "Ian".

Posted by Ian Price (Member # 14) on 06-26-2006, 07:42 PM:

Actually Ioan's name sounds like Yo-awn. However it too is Welsh and it also means John just like my name means John.

Posted by Joe Redifer (Member # 3) on 06-27-2006, 12:08 AM:

Unacceptable.

Posted by Manny Knowles (Member # 1171) on 06-27-2006, 09:06 PM:

Tom Holman's 10.2 lab uses elevation speakers behind the screen. But any processor that will handle 10.2 would need more than just elevation channels because there are additional surround channels too.

Posted by Martin Brooks (Member # 1269) on 07-05-2006, 07:14 PM:

quote:
quote: Frank Angel
And you can be sure someone is already thinking about putting a channel UNDER the seats -- they will call it envelope-up-your-butt-surround.

William Castle did it in the early 60s with first run showings of The Tingler (with Vincent Price). They wired some seats with vibrators so when the tingler got loose, it seemed like it was crawling through the theater. You should have heard the screams! Now this was showmanship!

Posted by Jarrad Salmon (Member # 3818) on 07-06-2006, 02:16 AM:

Although it exists, I personally don't see the point in it. I guess many people have the same view as me, seeing that it is not a regular installation.

Personally, I believe if a film is mixed right, sound will be percieved to be going overhead, when in fact it is comming from the surrounds. Kinda the same way sound can be percieved to be coming from the middle of two speakers in a stereo mix of a cd.

Posted by Brian Guckian (Member # 1678) on 07-08-2006, 12:21 PM:

Elevated channels behind the screen would also seem easier to retrofit in exisiting theatres than getting into the ceiling void and all that entails. You would additionally need more speakers for a "Voice of God" because of the relative depth of most theatres.

quote: Frank Angel
This thing about adding more and more channels has gotten a WAY out of control, IMHO. Sony's 8 channles makes you feel positively sensory challenged when you realize you only have those mere two wimpy ears to hear it all with. How will I ever appreciate all those extra channels?

To be fair, the great thing about SDDS-8 (and currently DTS-8) is the separation of music and effects from dialogue. With 5 stage channels, music and effects can be spread across the right, inner right, inner left and left channels, keeping the centre free purely for dialogue.

In the 5.1 system, music and effects are often mixed in with the centre channel dialogue to ensure a good spread, but keeping the centre completely free for dialogue gives terrific clarity.

I remember seeing Godzilla (7.1 mix) in an SDDS-8 theatre here on release and it just sounded fantastic - far better than 5.1.

Posted by Gordon McLeod (Member # 33) on 07-08-2006, 12:44 PM:

Imax has a centre top screen channel that works very weel with rocket launches and flyovers

Posted by Frank Angel (Member # 248) on 07-08-2006, 02:10 PM:

I would think that keeping dialogue locked into fixed center position, while it was necessary when mixing within the limitations of alignment-intensive matrixed stereo (put that dialogue anywhere but dead center, and in playback systems that were even slightly misaligned, it could wind up anywhere, especially in the surrounds), in discrete systems like 4trk mag and digital, you have the ability to have location-specific dialogue. Why waste all those channels if you are afraid to have dialogue follow the visual action? That was the beauty of 70mm and even 35mm 4trk mag -- they could (and DID) mix for sounds, even dialogue, to follow screen location. An actor could walk across a 65 ft screen and his voice would follow him perfectly. It was a beautiful thing, and it was all abandoned when the 4-2-4 matrix debuted.

Why should a rocket ship get the realism of sound following it, not only left to right, but from bottom to the top of the screen, while someone talking on the left side of a 60 foot screen has to have his detached voice coming from 30ft away?

There have been opinions voiced by some members here which contend that speakers placed above the screen instead of directly behind it will negatively impact the visual cues as to where a sound is coming in relation to its visual position on the screen. Well, if that is true and dislocated sound by speakers placed a few feet to the left and right of the screen and slightly above it can negatively impact eye/ear sync, how much more disconcerting would dialogue be if it's point source is 20-30 feet away from its corresponding image? And if anything, we are much more sensitive and much less forgiving of skewed vocal location where a person's voice is out of sync with his visual position, than, say, the music score.

I say USE those 8, 10 whatever channels; bring back location-specific dialogue!

Posted by Martin Brooks (Member # 1269) on 07-08-2006, 10:11 PM:

I have sought out SDDS-8 channel presentations on the few occasions when they've actually been advertised that way and I've never actually discerned the extra channels. In addition, I don't think I've ever been to an SDDS presentation that I thought sounded really good. Part of this is probably because both the acoustics of the theater and the mixes themselves are designed to present a sound field, not a discrete mix and it's possible that even the SDDS-8 releases, didn't do a separate mix, but instead just combined the adjacent channels, much like many later (non-Todd-AO) 70mm releases did with channels 2 and 4 before Dolby pushed the Baby Boom format.

I have a lot of respect for Tom Holman's work, but one of the things I disagree with is his insistence on that sound field.

I remember seeing one of the Lethal Weapon sequels (probably Lethal Weapon 2) in San Francisco at a THX certified theater (maybe the Coronet?). In that theater and mix, the dialogue was primarily center and the music soundtrack was everywhere but the center. I thought it sounded spectacular. It created a level of definition that you don't ordinarily hear in movie mixes.

I saw many 70mm films with stereo or panned dialogue and while I loved it then, I'm not sure how I'd feel about it now. As far as channels added for height effects, I can't believe it would add enough of a positive effect to be worth it. I don't think I've ever been able to actually perceive the center surround channel (Dolby Digital EX or DTS ES) and the height channel would probably be used even less.

Non-discrete sounding stereo has been a trend for many years- in music recordings as well as movies. Most stereo recordings don't have much more stereo in them than the stereo echo return. (You can hear the stereo portion of a 2-channel recording by switching to mono and making one channel out-of-phase with the other [L-R]). What's left is just the difference signal - just the stereo.

Posted by Steve Guttag (Member # 268) on 07-09-2006, 10:53 AM:

I am a big advocate of panned dialog. I also have found that you need 5-screen channels in most any theatre to pull it off. 3-screen channels never really works since phantoming dialog leads to poor clarity.

I have often complained about the hard center dialog leading to poor perceived lip sync and out and out confusing the brain.

Dialog above the action also does not work...I can't be in a theatre watching a movie for more than a few seconds before that drives me nuts.

Personally, I would go for 7 speakers across the front before I went for the first raised speakers. I would have 5 laterally behind the screen and one just outside the screen for "off-screen calls" that are not "surround" effects.

5-screen speakers works well for dialog because most every postion is good for the actors on the screen (1-shot, center; 2-shot, LC and RC, 3-shot, LC, C and RC...etc.). To hear this...go listen to a 70mm show of The Sound of Music.

For me, the priority would be 5-screen channels with one surround, then the second surround, then a 4-channel surround (Left-Side, Left-Rear...etc) so an effect can be pulled arround the audience)...then I would add the Left-Outside/Right Outside...then the Ceiling or raised channels.

In reality, who has time to mix for all of that? The sound MUST augment the story, not be the "star." When one is conscience of the technicalities of the show, it ruins the illusion...hence why I HATE hard center dialog. The only thing worse is "draped dialog" where dialog is louder in the center and "draped" into left and right to completely ruin the illusion.

Posted by Brian Guckian (Member # 1678) on 07-09-2006, 09:10 PM:

I remember reading though somewhere that panned dialogue caused editorial problems, i.e. problems in the cutting, and that's why it fell out of favour.

I think it was that when one cut from one angle to another, the actors could switch positions, and it was very difficult for the mixers to follow the action correctly. But with modern digital mixing desks, with their programmable faders, maybe it can be reintroduced.

[Dubbing theaters are really great places to visit BTW... you really appreciate the hard work that goes in to creating movie soundtracks]

Posted by Frank Angel (Member # 248) on 07-10-2006, 10:38 AM:

quote: Brian Guckian
I remember reading though somewhere that panned dialogue caused editorial problems, i.e. problems in the cutting, and that's why it fell out of favour.

I was at an SMPTE meeting where this issue was discussed and it seemed to be the concensus that only discrete channels were capable of handling panned dialogue whereas the Dolby matrix simply was not accurate enough. Keeping dialogue dead center kept everything nice and neat, if not dull and with all the shortcomings that Steve enumerated but without the worry that it would leak into the surrounds, a real no-no.

It's one thing if a special effect that you position to the extreme left or right bleeds into the surround, that only broadens the spacial feel of it, but dialogue bleeding into the surrounds is just a horrific artifact of matrixed surround.

On the other hand, there were also some filmmakers who chimed in that they didn't like panning, not because it was to difficult for the sound guys (sound mixers can do ANYTHING the director tells them....we are THAT good [Wink]

), but because precisely on those cut-aways, if you are keeping hard and fast to "absolute" true dialogue localization, the sound would have to jump back and forth with each cut, and THAT would call too much attention to itself. So in most productions where dialogue localization was used all those descrete mag prints of 60s and 70s stereo releases, a good sound mixer would compromise and cheat a bit to avoid just that kind of jolting audio switching. During the many years where there was no such thing as Dolby stereo and ALL we had were 6 and 4 descrete channels to work with and sound could be placed anywhere the director wanted it without worry about crosstalk, they pretty much learned how to do panning without drawing attention to itself, which is the goal of any cinematic process or special effect. (Aside) Which is why the idea of needing to put on and take off polarized glasses over and over during SUPERMAN is just a stupid gimmick and it reeks of ultra-assholism.

As for overhead speakers, to get this thread back where it belongs, I seem to recall that the Zeigfeld in Manhattan used to have ceiling surrounds in the early days, and I read somewhere, I believe in one of the earliest white papers on Dolby's 4.0 matrix stereo, probably in their SMPTE article, that overhead surrounds were discussed as a viable way to do surround. At the museum we have ceiling surrounds, not that it was designed that way -- in fact the original design had NO surround channel. When I was called in to run film there, I insisted they install surround speakers, but that, they informed me, would "compromise" the famous Japanese architect's design. I kept thinking, "....but we're running movies, the lights are out....no one is looking at his design." So I did the best I could with what I had -- luckilly the PA system used an array of ceiling speakers that was separate from the cinema system. I patched into that system and sent the surround channel into the PA ceiling speakers. It's passable, but just barely. It can't get up to reference level so it's OK for ambience surround mixes, but current day mixes that demand full range, full power surround playback, it pretty much craps out and since it's all 70v distribution, the dinkly little transformes that they are using just saturate and act as their own self-limiter. [puke]

Good thing they don't have digital in there yet -- one good explosion and that would just blow the little buggers apart. [evil]

Posted by John Hawkinson (Member # 1135) on 07-10-2006, 02:13 PM:

I guess I don't really understand how the matrixing algorithm works. It sounds like, Frank, you are saying that a signal panned into the left channel is more likely to bleed into the surrounds than a signal solely in the center channel?

I would have thought -- since the center channel and the surround channel are both represented by out-of-phase information in-common between left and right -- that center channel sound would be most likely to bleed into the surrounds, and left and right sounds would be least likely.

Is that wrong?

Posted by Oscar Neundorfer (Member # 458) on 07-12-2006, 12:00 AM:

John,

Center channel material is represented by in-phase and equal level on left total and right total channels from the soundtrack. Surround is basically out-of-phase and equal level material between left total and right total.

As long as center channel material is derived this way, then minimal leakage to the surrounds will result. A matrix is not perfect, however, and neither is the mix and the a-chain setup, so long ago and far away, time delay was added to the surround channel to help mask what little crosstalk occured. All in all it works pretty well.

Posted by Sam D. Chavez (Member # 1841) on 07-12-2006, 10:55 AM:

Ah, panned dialog. What a subject. Even if mixed perfectly on mag or 5.1, whatever, the timbre of the actors voice always sounds just different enough on channels other than the center.

Even if all the speakers are identical the left and right can gather more bass from the closer proximity to the front corners of the theatre and tend to sound chestier or heavier. If different actors are talking to each other across the screen, it sounds OK but then is very level dependent.

The surrounds are a whole other matter and an even worse problem.

Placing dialog only works in a very controlled situation

Take that Steve G. who is loading his weapon as it were.

Posted by Mark Gulbrandsen (Member # 72) on 07-12-2006, 04:08 PM:

I pretty much agree with you Sam. In the old days of more limited bandwidth A & B chains the obvious differences in overall speaker sound didn't matter as much but today its a different story with wode band material and playback systems... You're right with side speakers being in closer proximity to the wall, it really does have an effect on lower mid and down. If only everyone built their rooms an extra 30 feet wider than the screen was!

I say Thank God that Sony is now really a dead issue and that they get to meet the dumpster as they die.

Mark

Posted by Steve Guttag (Member # 268) on 07-12-2006, 07:07 PM:

Actually, Sony still has 8-channel films on the schedule. In fact, they probably outpace Surround-EX.

As one that has heard panned dialog in a great many places over a great many systems...it almost always is a worse experience with a hard-center dialog...it is most un-natural. While it is true that panned dialog can be done wrong and annoying, there is no reason it has to be. Rules need to be developed and learned just like the 180-degree rule for shooting the picture.

The Sound of Music is an excellent example of panned dialog done right...2001 is another one and it shows they figured out how to pan dialog without being distracting...there are times when the dialog will NOT be where the actor is because shifting it at some points would be distracting yet keeping it where it was last heard works AND gives directional cues.

Dialog in the surrounds almost never works...except for "HAL" in 2001...HAL is everywhere and it adds to his creepiness.