This is topic Dolby SRD overhead channel in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Brad Morris (Member # 1175) on 12-07-2002, 10:33 PM:
A friend who works for Dolby in LA told me about a theatre in Arizona that ran We Were Soldiers with a discreet track for overhead speakers. The SRD track has room for 18 channels with 2 reserved for visual/hearing impaired info. Does anyone know anything about this, or at which theatre it was?
Cheers-
Brad
Posted by Michael Schaffer (Member # 1204) on 12-07-2002, 11:00 PM:
Here is the Dolby press release about the overhead channel:
Dolby Overhead Cannel
The overhead channel is the fourth channel derived from the matrixed surround channels. I believe there was a discussion of the subject on this forum not so long ago.
Posted by Joe Redifer (Member # 3) on 12-08-2002, 01:22 AM:
If SRD has room for 18+ channels, why do we have the wimpy matrixed EX rear surround instead of discrete?
Posted by Frank Angel (Member # 248) on 12-08-2002, 10:29 AM:
Hmmmm....18 channels -- let's see....5 up front, 5 on the rear wall, 2 on the left wall, 2 on the right wall, 2 in the ceiling and 2 under the seats. That should do it, unless director Randell Wallace can think of some other place he wants his helicopters blasting from some other location, perhaps in the middle of each patron's stomach. Given some of the reviews of this picture, it might be better for a director to worry a bit more about story line and character development than the sound of a helicopter coming from the ceiling.
Frank
Posted by Bobby Henderson (Member # 840) on 12-08-2002, 02:48 PM:
The Dolby AC-3 encoding format is limited to six discrete channels. No more than that. One can apply matrixing methods to artificially create more faux audio tracks, but they would not be discrete. It would take a complex setup of three Dolby Digital units processing three separate AC-3 bitstreams to create a discrete 18 channel format.
This is partly why Dolby Digital Surround EX is a 5.1 format and also why Dolby Labs could not counter DTS' ES-6.1 Discrete process for home theater with a true 6.1 format of their own. FYI, DTS CAC format for home theater can support up to 8 channels.
Perhaps if Dolby were to develop a next generation sound process for commercial cinemas using the MPEG-2 AAC codec (which Dolby does promote and distribute) then a process using 18 discrete tracks would be possible. The Advanced Audio Codec can run in a very wide variety of bitrates and can feature as many as 48 discrete audio tracks in a single bitstream. Another advantage of AAC is it uses more efficient data compression techniques than even Dolby Digital AC-3. As it stands, AAC is mainly being used for things like Internet based or satellite based audio transmissions (typically only in 2 channel form). Some people feel AAC may, in the long term, supercede the MP3 format for storing compressed music material.
Posted by Frank Angel (Member # 248) on 12-09-2002, 08:55 AM:
Here's a question -- can I take an old Cat 150 matrix card and feed DTS or SRD Ls + Rs into it and derive the center surround that way? I've already got two center clusters on the back balcony wall as well as JBLs as hefty point-of-source surrounds in each corner (no wimpy side surrounds). I was even thinking of using my old Sansui Vario Matrix II decoder to extract Left Corner Surround, Left Center Surround, Right Center Surround and Right Corner Surround, getting two center rear channels instead of only one. Of course that would be over kill, winding up with more rear channels than behind-the-screen channels (although there is no reason why they couldn't matrix an two additional channels on the Lf & Rf discretes for 5 up front); I would be happy for a single center surround which I am thinking could be easily extracted from a matrix card, neatly jammed into a 1u rack case.
Posted by Gordon McLeod (Member # 33) on 12-09-2002, 02:44 PM:
I have used old CP50's to give me EX with 1/3 octave eq on the surrounds
Posted by Frank Angel (Member # 248) on 12-10-2002, 12:28 PM:
Sweet.
Posted by David Stambaugh (Member # 1102) on 12-12-2002, 08:48 PM:
Article by Smart on their overhead sound technology (covers both cinema and home-theater).
Smart Overhead Channel
Posted by Paul Linfesty (Member # 214) on 12-12-2002, 09:20 PM:
This is so much overkill. Two or three surround channels are plenty, IMHO.
Posted by Ted Costas (Member # 473) on 12-17-2002, 06:00 PM:
In my humble, personal opinion, it sounded great on We Were Soldiers here in the Dolby LA Office Screening Room. As a matter of fact, I think the speaker is still on the ceiling, hold on a second, let me check...
Yep, it's still up there. There just isn't a helicopter flyover like one with Dolby Surround EXG, that's EX plus the "voice of God" channel. I just made that up, by the way. Please don't be calling and asking for EXG, it doesn't exist... unless you are the director of We Were Soldiers.
Yours, Ted
Ted Costas
Director
Dolby Distributor Servives
Posted by Bobby Henderson (Member # 840) on 12-17-2002, 06:27 PM:
"Dolby EXG" actually kind of has a ring to it. Maybe I'll throw together a mock-up of a logo...
"After experiencing Dolby*EXG, certain listeners needed an EKG." ![[Cool]](cool.gif)
Posted by Joe Redifer (Member # 3) on 12-17-2002, 07:31 PM:
AWESOME! Great work Bobby!
I demand to know what future releases will be in Dolby Digital EXG. I will start informing customers of this new technology right away and posting this great news on every internet forum I come across. (just kidding, Ted ![[Smile]](smile.gif)
)
Posted by Ted Costas (Member # 473) on 12-18-2002, 04:24 PM:
See what happens when I open my big mouth...
Very funny, Bobby. Joe, I would expect nothing less...
How about some marketing slogans, "A sound system that will impress Him." "God Bless this theatre." "Got God?"
Of course, these are not the opinions or expressed marketing campaigns of Dolby Labs or any of it's companies. Just me, Ted, lurking on the Film-Tech forums.
"I want my EXG."
Yours, Ted
Posted by Christos Mitsakis (Member # 143) on 01-09-2003, 06:57 AM:
In the current issue of Widescreen Review mag there is an article covering the Todd-AO/Soundelux and Dolby Laboratories's "Envelop" (Hight) channel regarding the presentation of "We Were Soldiers" in September 20 2002.
The article concludes mentioning that "Star Wars II - Attack of the Clones" DVD release is full of Envelop channel material.
Anyone ever heard the info that SWII was mixed with this extra channel? And If so on DVD, I suppose the theatrical release should be the same.
Christos.
Posted by System Notices (Member # 2357) on 07-15-2005, 10:16 AM:
It has been 918 days since the last post.