Cinema Sound with Ioan Allen
Dolby Podcast Episode 21, August 16, 2007
Get the real story about the evolution of sound in the movies from the early 1970s to present from Ioan Allen, an Oscar Award-winning Senior Vice president of Dolby Laboratories, who has been instrumental in getting great sound into the movies.
Hear them all: Listen to Dolbycast on iTunes® or subscribe using your favorite RSS reader.
Mentioned in this Episode
Jack Buser: Hello, and welcome to Dolbycast, the insider's guide to entertainment technology from the experts at Dolby Laboratories. I'm Jack Buser.
Craig Eggers: And I'm Craig Eggers.
Jack: And we're here to give you the straight talk on everything you need to please your ears.
Craig: Well, Jack, it's summertime in San Francisco.
Jack: Yes, the end of summertime, I might add. I've got a tear in my eye with these clouds rolling in.
Craig: Now, did you go out and build an outdoor home theater system like we talked about the last time we...
Jack: I did not. Remember I live in an apartment in downtown San Francisco ; so there's no such as even outdoors, let alone an outdoor home theater.
Craig: Why, I think, I've asked you all the questions we are going to ask on this particular podcast because we have a very special guest coming up, and in our next podcast, we are actually going to do listener questions.
Jack: Thanks right. Just because the guest today is so special, we got Ioan Allen, Senior VP here at Dolby Laboratories. He's going to tell us all about how Dolby got involved with the cinema, the history of the cinema. We're going to hear, I'm sure, all kinds of wonderful stories.
Craig: If you are interested in movies, and how they were made and how they sound great, this is the man you want to hear from.
Jack: This is the man. So, we're going to skip listener questions today, and then, next podcast we are actually going to do the entire podcast with nothing but listener questions.
Craig: We're running so behind.
Jack: We're running so behind. Everyone, we apologize for running behind. Hopefully, we make up for it in the next podcast, where we're just going to answer as many questions as we possibly can.
Craig: So, let's go to a quick break, and we'll reintroduce our guest right after this.
Jack: You got it.
Announcer: You're listening to Dolbycast. Got questions for Jack or Craig? Email dolbycast@dolby.com.
Jack: And, we're back here at Dolbycast on this foggy summer day with special guest, Ioan Allen.
Craig: Mr. Ioan Allen.
Jack: Senior VP here at Dolby Laboratories who is going to be telling us all about Dolby and the cinema.
Craig: You know, we refer to Jim Hilson as God; so how do we refer to Ioan?
Jack: I don't know, God of Gods, maybe.
Craig: God of Gods, maybe.
[laughter]
Craig: Ioan, you've been with Dolby for how long?
Ioan Allen: Great, Jack. Thanks for having me here. I've been with Dolby since 1969, so I'm into my 38th year, I think, and that takes you back somewhat to just after the flood.
Craig: Just after the flood. [laughter] You have been so instrumental in bringing surround sound to movies. You have been so instrumental in movie production. Tell us about the first surround sound movies, how that happened, how that transition from just watching movies in stereo to all of a sudden having the ambiance of surround sound in the theater, what that brought to movies and your involvement with it.
Ioan: I think, I have to go back further and go back to Dolby's beginnings, which were in noise reduction. You all remember analog tape recording and the hiss. Well, we started out in that marketplace professionally as well in the consumer field. The professional marketplace gravitated towards multi-track tape recorders in the late 60s, early 70s.
My job was to get all 16-track recorders equipped with A-type noise reduction. We did that pretty well so that by 1972, 100% of all the multi-track tape recorders, in London, New York, San Francisco, Los Angeles, had 1 channel of our noise reduction on every track.
The market was saturated, and there was a limit to how many 16-track tape recorders were going to be sold. And I thought, where else is there a serious noise build-up. And then, thought of the film industry, where at that time there were lots of magnetic analog recorders, numerous generations of effects, start-up music copied again and again and again before you get to the release print.
As a result, there was a lot of hiss, a lot of noise and a lot of distortion. So, I thought, “this is going to be easy.”
[laughter]
Ioan: I'll knock on a few doors, and we've got a whole new marketplace. Well, it wasn't easy. It was a long hard push.
Craig: What were the challenges?
Ioan: The challenges are that there were a lot more than that high hiss level. One of the challenges dates back to the quality of the loudspeaker that was in use in the early 70s, which in turn, dated back to probably basic designs that came from the 1930s, when loudspeaker design had to be efficient rather than low distortion. In order to get that efficiency, they had a lot of mid-range energy, but nothing at the low frequencies or high frequencies. So, you get a very thin, emasculated sound.
And in the cinema that loudspeaker was stuck behind the screen, which further diluted the high frequencies. So, the poor mixer in the control room mixing the movie would crank up the highs in an effort to compensate for this terrible high frequency response, and that led to gross distortion.
What we did by providing noise reduction on the magnetic tracks before you got to the release print, the optical release print, was reducing the noise, but it still sounded like the pits. [laughter]
We had to make some more fundamental changes, and those changes involved equalizing the loudspeaker that was behind the screen. We discovered that if you reduce the efficiency with a third octave equalizer, but cranked up the high frequencies and trimmed the response to be flat, you could get something that's approaches what I call 'mid-fi.' It may not be hi-fi, but it was something much better than anything that was around at the time.
Then, of course, you begin to hear the hiss on [indecipherable]-tracks and you hear the hiss from the optical - so the noise reduction comes in. So, we realized that it wasn't just a matter of getting noise reduction into the film industry, but this whole package of equalization, noise reduction, and then, a whole new slew of mixing techniques for the mixers because the sound was like nothing they had heard before.
The choice of microphones on location had to be changed, because the mic were being selected for a rising high frequency response. Instead of that, you started wanting to use flat mics. There was a tendency to drift towards lavalieres. Now, I've got nothing against lavalieres, but they never really sound like a person. You may understand the words, but it's not real.
So, I had to campaign for things like going back to boom mics. A whole arsenal of changes had to happen to get what we now understand is the Dolby film program to work.
Jack: So, you were working all up and down the chain then. You were making changes in the actual exhibition, and then all the way up to the microphones that were being...
Craig: All the way to the acquisition.
Ioan: All the way back.
[crosstalk]
Jack: Of course. Of course.
Ioan: Now, we're still talking about mono. About 99% of all the films released and heard, say, in the early 70s were mono optical sound tracks, photographic sound track. Magnetic stripe was extremely rare because it was very expensive, and it would be used for an occasional road show, and then only in big cities.
At that time, think back, most people, many people had only mono in the home. There was no stereo or very little stereo. We decided around 1974 that we would plug in a revolution and try and get more stereo into the theaters. We took the mono optical sound track and split it in two and demonstrated that you could get 3-stage channels - we haven't even gotten to surround yet - very effectively out of the conventional sound track.
Craig: So, those 3 channels were left, center and right.
Ioan: Right. Now, think about this for a minute. What would take the industry then is, instead of a mono sound in the cinema that goes from about 150 Hertz to 3 Kilohertz; we were introducing a stereo sound that goes from probably 50 or 60 Hertz out to about 10 Kilohertz. This is 'whoa'!
Jack: That is a huge change.
Ioan: Not only that, but we introduced it in such a way that the characteristics were pretty compatible for mono playback. So, we didn't have to issue 2 separate versions of each print, which is anathema for film distribution. You've got to have a single inventory release; otherwise, it's just not economically viable.
Jack: Because there were probably still a lot of theaters who could only do mono for some time.
Ioan: Yep. Absolutely. And the distributors began to like us. It's always been the case to get a new format established. It's the auteur, the film director that really pushes the buttons. It's not the studios. The studios hate change. At least they did in those days. So, I would be lobbying the Stanley Kubricks, the Ken Russells, whoever it happens to be. And occasionally hit a good one and they say, “yes, we'll let you do a release”. That led to the first commercial release in Dolby Stereo, which is a film called Lisztomania by Ken Russell.
Jack: Ahh, Lisztomania.
Ioan: Featuring Ringo Starr as the Pope.
Jack: And listeners out there, if you haven't seen Lisztomania, did that ever come out on DVD?
Ioan: Oh, yeah. I've got a Laserdisc as well.
Jack: So, that's the first movie that ever used Dolby?
Ioan: Dolby Stereo. We had mono releases before that. That was the first stereo release.
Jack: Right. This is a fabulous movie.
Ioan: Rent it, buy it.
Craig: Ioan, just for our listeners who don't know, you talk about a magnetic track on film. Can you explain that for our listeners?
Ioan: Yeah. Most films are still heavily reliant on the photographic track, which is an analog varying width of black and white track on the side of the film.
Jack: You shine a light through it, right?
Ioan: You shine a light through it, and the modulation is caused by the varying width of the black and white track. This is so difficult to do on sound only. I'm eager to get a piece of paper out and show you a drawing.
[laughter]
Jack: It's like a picture of the waveform, if you will, printed on…
Ioan: Absolutely. Now some films, back in the 1970s, up until the late 1980s and early 1990s, were released with mag stripe. In this case, what they'll do is they'll print the picture onto the film. Then, that film is taken to a different company where a magnetic oxide stripe is painted on the print.
With a 70 mm print, it's one, two, three, four separate stripes of varying widths. Then, the film is baked dry, to harden the oxide. Then, it's taken to another place and recorded in real-time. So, by now you'll realize that the cost is just unbelievably extravagant.
Jack: Oh, I'm sure.
Ioan: Each print has to be separately recorded in real-time. In fact, it's more than real-time, because the operator has to change the reels. So, that the cost of a 70 mm print was, I think, in the order of $30,000, compared to a 35 mm print, where we're talking about $1,500 at the time.
Jack: Wow.
Craig: Wow.
Ioan: So, that's why, not only was there not much 35 mm, but limited 70 mm releases, because of the cost.
Jack: So, we've talked about up to 3 channels up to this point. Let's talk a little bit about surround sound. How was surround sound born? Was this an epiphany, if so, by who? What were some of the first films?
Ioan: We went to Barbara Streisand, her production company, to try and get a release of A Star is Born in Dolby Stereo. They said, “OK, we'll do it, but only if you can do an effects track”, which was what the surround track was called in those days. It was literally effects. It switches on, switches off. It wasn't like ambiance. It was with clear cut effects.
Well, I went to the engineering department. I said, “can you do this? Can we find a way to encode surround material in?” Oh yes, they said, “how long have we got?” I said, “you've got until December.” This is 1976. July passed, August passed, September passed, we got to October.
[laughter]
By this time, I'd committed to First Artists [Production Company –Ed.] to provide a surround channel off the optical. There are things you can't do. You can't put the surround on the other side of the film, because then you cease to have single inventory. You've got to find a way to code it into that track.
So, I frankly then kludged together a combination of Sansui's QS matrix system, a delay line to suppress crosstalk. People think that delay on Dolby Surround is to do with sound effects or something, but it isn't, it's just to reduce the crosstalk. And a Dolby B decoder to take the noise out of the bucket brigade delay we were using.
Lo and behold, I had a working surround system. Demonstrated it to First Artists, they said “fine”, and that became the first film in Dolby Surround. And that stayed to this day as the basic thing that developed into ultimately Pro Logic II.
Jack: To this day. You're absolutely right about that.
Ioan: Obviously, it's been greatly matured since then. The nature of the matrix has changed. The whole thing has got more sophisticated, but that was the origin of it, “we've got to do this for A Star Is Born. ”
Jack: Well, listen Ioan, this is all so wonderful. We're going to go to a break, when we come back, I want to know what that Sansui box is all about.
[music]
Announcer: Thanks for listening. This is Dolbycast.
Braden Russell: Hi, I'm Braden Russell.
Ara Derderian: And I'm Ara Derderian and together we're the HT Guys. You're listening to the Dolbycast, and if you've got a question about audio, where do you send it?
Braden Russell: To dolbycast@dolby.com.
Jack: And we're back here at Dolbycast with a very special guest, Ioan Allen, Senior VP here at Dolby Laboratories, who's telling us all about the early days of cinematic surround sound.
Now, you mentioned a particular Sansui box and I'm quite a gear head as our long time listeners probably know well by now. What was this? What was this Sansui box that you used to build the first Dolby Surround Sound system?
Ioan: Well, Jack, any of your old listeners will remember back in the late 1960s and early 1970s, quadraphonic sound, which was an attempt to get that 4-channel sound into the home. There were three main competing companies, Sansui, CBS SQ, and JVC. The Sansui system known as Sansui QS was a matrix system as was the CBS SQ system.
I believed at the time that the QS system was slightly superior. Quadraphonic sound died out in the home, but lo and behold, we had a few Sansui boxes around. So, that was a convenient way to get a matrix encode / decode system. It wasn't really optimized for film use, which is why, back in 1978, I think, we changed the matrix, to one that we refer to as the MP Matrix, which is what's in use to this day.
The MP Matrix was predicated on the idea of two axis, front to back – in other words, center to surround - and left to right across the screen, where as the QS matrix was slightly offset. But, it worked well enough for us to be able to release A Star is Born that way, and a few other films - before we got to May of 1977, which was the release of Star Wars, which represented a huge jerk in the number of theaters we had equipped.
Craig: And you know, Ioan, that's the movie that most people associate with surround sound. For the majority of people, it was probably their first experience with surround sound in the cinema.
Ioan: Yeah, well, Star Wars really was, for most people, a revolution in the cinema. It was a revolution for the film industry as well, because here we had a single inventory release. That meant that every Star Wars print in every theater was capable of being playing in stereo with surround sound. And in those days, films lasted in the cinema much longer than they do today. Today 3 or 4 weeks is a good run.
Craig: Yeah, and then out to DVD.
Ioan: But, now days it's very short. Those days things were very long. Star Wars could last in some theaters for 6 or 9 months, which meant that as the success of the film developed, theater owners knew they had the stereo capability. So, they said, "We'll put it in, I'm going to pay for it in 5 days."
Of course, the cost to them was significant, not just because of the cost of the Dolby equipment, which is pretty small, but many of the theaters were mono theaters that had to put in extra power amps, extra loudspeakers, hire a crew to hang surround speakers. But, the theater owners really thought the investment was worthwhile.
And on the tail of Star Wars, of course, came other films like Close Encounters [ of the Third Kind –Ed.], which solidified the growth. Now, there was some new technology that we introduced on Star Wars, not on the 35s, which were really the same process as I described that we used on A Star is Born, but, on the 70 mm prints.
Prior to Star Wars, 70 mm releases, which used 5 channels behind the screen and a single surround channel, typically would make a 4-track master and then literally mix together left and center to create half-left, and mix right and center to make half-right. And if you had a musical like A Star is Born, which had already got the voice spread over - tracks, you finished up with a big, out of phase mono.
[laughter]
Ioan: If you think about it, with a flat screen, there's no way you can get a coherent point where all the signals are in phase. If you have the same track going to every channel, but lo and behold, you get “woof”.
[laughter]
Ioan: Well, Gary Kurtz, the producer of Star Wars and I were talking about the sound for Star Wars, and I said “there's got to be a better way to use those extra 2 tracks”. Now, the typical loudspeaker of that time was an Altec A4, which had a pretty falling response below about 80 hertz, maybe 100 hertz. And I thought, “let's use those extra 2 tracks as a kind of sub-woofer setup”.
Jack: Yes!
Craig: Jack's favorite channel, by the way.
[laughter]
Ioan: You can overdo it, so watch out.
[laughter]
So, we used those 2 extra channels, 2 and 4, just to carry bass information. That was driven into the bass bins of channels 2 and 4 behind the screen in 70 mm-equipped theaters so as to extend the effective response. So, by only using 3 channels behind the screen, we got a better, more discrete signal for the mid and high frequencies and it got an improved bass response for low frequencies, which, of course, was significant for Star Wars.
I remember sitting and watching audiences as that opening ship comes up over your head and hearing that rumble and hearing these voices say, "Oh, my God. Oh my God" as the ship went over head. Pretty exciting stuff.
Craig: How cool was that?
Ioan: That was cool. I was going to say that I'd say it was “hot”.
[laughter]
Craig: Truly. To this day, Ioan, one of my favorite demo discs in my home theater, anybody comes to my house, they've got to hear Apocalypse Now. The most recent version of Apocalypse actually has a whole segment about your involvement in the production of Apocalypse Now. [ Apocalypse Now – The Complete Dossier –Ed.]
Ioan: We wanted to see a way to get stereo surrounds. In order to get a 360 degree sound field, you can't do that with a mono surround track. If you have 4 speakers precisely separated at 90 degrees, you won't get far from it, but not as good a separation as you'd like. Especially when 3 speakers are behind the screen, because obviously you're then trying to cover over 200 degrees with the surround channel, in terms of the circle that's surrounding the listener in the cinema.
So, in order to get stereo surrounds, how do you do it on a 70 mm print without risking compatibility? And lo and behold, we thought of a way of doing it and did a test release on Superman, which must have been 1978, I think, that's right. Plus or minus one year. Plus or minus one dB.
[laughter]
Ioan: We did a test release on Superman, didn't announce it. And then we were able to propose it to Walter Murch, who was in charge of the sound for Apocalypse Now. The way we did it was, I think, back a minute I talked about using channels 2 and 4 for low frequency information only. Why not use the high frequency part of channels 4 and 4 to provide left and right information for the surrounds?
Leave channel 6 as the mono surround track, which it used to be before. And lo and behold, suddenly you've got a print that you could send to any theater, whether it's equipped for stereo surrounds or mono surrounds, and the right information is on the tracks.
But, remember, there were still a very limited number of 70 mm theaters, compared to 35 mm theaters. So, I'm guessing now that maybe 20 theaters in the U.S. were all that played Apocalypse Now with its stereo surround track. And that, of course, is what today we know as 5.1, and it wasn't called 5.1 for many years after Apocalypse.
There was a marked reluctance to release films in 5.1. I don't know why. I think, it was the shortage of effects, the extra difficulty, a fear on the part of the director that it would take longer in the mix. But, we were doing barely half a dozen a year after Apocalypse, until we got to digital releases in the early 1990s when things started really getting out in 5.1.
Jack: So, talk a little bit about that digital revolution, the transition from these analog soundtracks or optical soundtracks to a digital soundtrack. What was it like there during that transition? What caused Dolby to go from analog to digital?
Ioan: We have to go back. You're jumping ahead a bit. Or maybe, I am.
[laughter]
Ioan: We ought to talk about SR.
Jack: Oh, definitely. Absolutely. How could I forget?
Craig: My favorite, my favorite soundtrack.
Jack: My favorite as well.
Ioan: Back in 1986, actually from 1984 for a couple of years, Ray Dolby was working away coming up with an improved analog noise reduction system. All the stuff I've been talking about before in noise reduction was what was termed A-type noise reduction, Dolby A-type. Many of you may remember the days of Dolby B-type, the consumer system.
In the professional field, we went from A to Ray's new process that was called Dolby SR. It was the most complicated circuit board for analog that's virtually imaginable. It's very, very complicated.
In sound terms, it was a brilliant invention, because rather than just providing noise reduction, it does what I call “ signal wrapping ”. If you have a spot tone, a single tone, whether the medium is magnetic or whether it's photographic, there tend to be different noise components that come in with it.
Obviously, there's a high frequency hiss, but you also get modulation effects around the tone itself. And you will get some low frequency effects around the tone itself. What SR managed to do was to rip all that noise and distortion component out, leaving you just with the pure tone. It's an extraordinary thing to switch in and out to compare the ockling and cockling and hiss that you get with noise reduction switched out, and then to switch SR in. It's spectacular.
So, we introduced SR on film in 1988, I believe, with Robocop and Inner Space and that gradually became the standard analog recording process. To this day, every 35 millimeter film out of the U.S. has a Dolby SR soundtrack on it, even though we've proceeded to digital as well.
And some people will tell you that SR, while it has its limitations, as a format on film, it's still the best sounding thing that you can find. It is a little limited in terms of dynamic range. You can't get an ultimately loud sound. But, many a film you don't need an ultimately loud sound, and it would be inconvenient to try and do stereo surrounds off the optical in the cinema. But, in every other respect, it is a low distortion, perfect sounding medium.
Craig: It is so warm.
Jack: We actually have used SR tracks for Dolby TrueHD demos.
Ioan: I would not use the word warm, I'd use the word clean.
Craig: OK.
Ioan: And I still stand by it as great. My demos on film are spectacular. Most people would think they're listening to a digital track. In fact, you can make a case for the fact that analog is a much more difficult medium to handle. But, correctly handled, it can still sound better than digital.
[laughter]
Craig: Whoops.
Ioan: But, now you have a problem, which is that there are fewer and fewer people who can take the patience to align a recorder, to bias it, to set the recording queue correctly. And the cost has become prohibitive.
Digital today, for a digital recorder is unbelievably cheap. This is why the studio system as we used to know it 20 years ago has fallen into a bayonet, because now everybody can afford to build a studio in their garage. I hope they get better sound deadening, but never mind.
[laughter]
Jack: So, why digital?
Ioan: So, now we move on to digital. One of the reasons is to get more dynamic range, to get a louder sound, a rock and roll movie, a war movie, you need more impact. The second reason is to find a convenient way to get stereo surrounds. And the third reason, frankly, is marketing.
Jack: That's right.
Ioan: Because the public in the early 90s was led to believe, rightly or wrongly, that digital was better. Pretty soon we'll have digital toenail clippers.
[laughter]
Ioan: And your nails will be so sharp. And the LCD printout will have the date and time stamp on it.
There was competition. We had other companies in the field saying “we're going to use digital sound”. And they made some terrible mistakes. Our first competitor in digital sound on film made the mistake of putting the soundtrack in the normal analog soundtrack area.
Mistake #1 is, you suddenly can't have single inventory release because you can only send that to a digitally-equipped theater. Mistake #2 is, if the digital fails, there's no backup so all you get to hear is... [makes hissing noise]
[laughter]
Ioan: We realized that we had to leave that superb sounding SR track where it was, and put digital data somewhere else. And that's why we chose to put it between the sprocket holes.
By that time in the early 90s, we were already an expert company at compressing digital data for other applications in broadcast. We came up with a very effective way to reduce the number of bits you needed to create this 5.1 high fidelity track. And as a result, increase the bit size to the point that the whole soundtrack is very robust in terms of damage, because prints are given a pretty hard time in cinemas.
Jack: Listen, we better take a short break. When we come back, I want to hear what it means to put the data in between the sprocket holes.
Announcer: You're listening to Dolbycast with Jack Buser and Craig Eggers. Be sure to log on to Dolby.com.
Craig: And we are back with Mr. Ioan Allen, of Dolby Laboratories. A true pioneer in cinema sound; and not just surround sound, but as we learned earlier, stereo...
Jack: You name it! Fidelity, you name it...
Craig: Sub-woofers...all those cool things.
Jack: You got it! Now you mentioned going to digital. That one of our big innovations with digital sound in the theater was actually putting the data between the sprocket holes on the film. Can you talk a little bit about that?
Ioan: Sounds tricky, doesn't it?
Jack: Yes...
Ioan: In fact, you'd be amazed at how many people ask me why the sound doesn't run at 96 Hertz with a constant buzzing in playback, which is what you think might happen.
[laughter]
Ioan: Because there are 4 sprocket holes for each frame of picture. The frames go at 24 frames a second. This means 96 blocks per second are going past. Why don't hear... [makes fast rattling noise]
[laughter]
Craig: So, Ioan, why don't you hear... [makes fast rattling noise]?
Ioan: Well, the answer to that is - think of a bucket. And you're pouring the bucket into a barrel of water. Even though you are pouring the bucket in one at a time - splash, splash, splash - you can have a tap at the bottom of the barrel and the water will come out continuously. That's a pretty neat way to think of the bitstream as coming out constantly.
We do some other stuff, though that's pretty nifty, which is that we don't analyze it as a bitstream until after all the bits in a certain block have been put into memory. And only then do we restore it as a series of lines in a 2-dimensional matrix before analyzing it.
The net result is that out of, I think, it's 560 kilobits raw per second, that 360 is pure audio. The rest is overhead. And the reliability rate is really good. And theaters can run a print for a pretty long time.
Jack: Right.
Ioan: People ask me whether the analog last longer than the digital or the digital will last longer than the analog. My answer is that you can't really compare them, because it's a very different folio mechanism.
Jack: That's right.
Ioan: The analog will develop scratches and tears. The digital will work fine for 70 weeks and suddenly will go dead.
Jack: Right. Right.
Ioan: But, the neat thing about the way we're doing it is that you can revert them to the analog on the rare occasions that happens. Our modern theater equipment reverts seamlessly. So, you don't even notice the reversion unless it happens to be a piece with really loud effects, where the SR can't keep up.
Jack: That's right. Every time I walk into a theater and I see the Dolby trailer play before the movie, I always know that I'm in for a treat, because I'm actually going to be able to hear the movie in its entirety. That's not necessarily the case if you're watching a movie that's in its second week of running with, maybe...
Craig:.. .with some other soundtrack...
Ioan: It's worth recapping what we've got here. On the standard 35 mm prints, which to this day are going to every theater pretty much in the world now, you have a Dolby digital track. It has a really good fidelity and it's really robust because of the bit size.
We selected those parameters very carefully. The alternatives were to have a smaller bit size, which one of our competitors did. Potentially that leads to unreliability issues because the bits don't survive the wear and tear in the theaters.
Alternatively, you could consider having the data on separate media and running something in interlock. The problem there is, does the media turn up?
[laughter]
Ioan: Somebody said, if you take the audio off the film, the first thing a good engineer will do is to find a way to put it back on again. So, we think, we did our homework well and did really good engineering.
Of course, that's not the end. There're always further developments. The next step was brought to us, actually, by Lucasfilm prior to the release of Episode 1. Gary Rydstrom, the mixer of Star Wars: Episode 1, came to us and said “could we come up with a way to put in more surrounds tracks”? And we did. We came up with what is now known as Dolby Surround EX, Dolby Digital EX.
The parameters that went into the thinking behind that were parameters that we talked about before. Fundamentally, you want a single inventory release. You can't afford to do anything that requires dual prints. The way we did it was to say, well we can't change the bit size. You can't put bits on the other side of the film because all those things would warrant having dual inventory.
So, we came up with the EX idea and we have a patent on the idea - encoding with a matrix. Three surround tracks into 2 channels. Sorry, three channels into 2tracks; got that one backwards.
[laughter]
Ioan: So, we have left, center and right on those surround track.
Jack: So, it's a 6.1 system.
Ioan: It's a 6.1 system. And as you know that's crept into home use as well, because that same information automatically is carried onto DVD, because it's coded into those 2 tracks. There's no separate coding required.
It's worth pointing out that many a home system now is rated as a 7.1 channel system. You have to be very careful of that, for those of us in the film industry, because 7.1 means something completely different. A 7.1 in the film industry means 5 channels behind the screen, and a left surround channel, and a right surround channel.
Craig: Right.
Jack: Interesting.
Ioan: Whereas 7.1, you guys have in the home have 4 surround channels and 2 channels up front and a center.
[laughter]
Jack: That's right.
Ioan: So, caveat emptor.
Jack: Absolutely. Well, I've got to say it is such a pleasure having you here on this podcast. I know all of our listeners certainly appreciate all this information. It has been so interesting, so enlightening for me.
Craig: Ioan, a pleasure and an honor, quite frankly.
Ioan: It's been great to have me here.
[laughter]
Jack: I love it! And Craig, you got to talk about Apocalypse Now again...
Craig: My favorite movie...
Jack:. ..everyone out there in the audience, listeners - we didn't do a listener question this time - but the next episode is going to be nothing but listener questions. I really hope everyone out there enjoyed this time with Ioan Allen.
If you have any questions for us here at Dolbycast or even Ioan himself, please write in and we'll be happy to get back to you, we hope. Not to speak for Ioan, but hopefully if there's some inquiring minds out there...
Ioan: Fact check, that's great. It's been great. Thank you.
Craig: Bid thee well. I'm Craig Eggers.
Jack: And I'm Jack Buser.
Craig: And this is...
Jack and Craig: Dolbycast!
Ioan: Alright.
Jack: Thank you, Ioan.
Craig: Thank you, Ioan.
Back to Top
Back to Dolbycast main page
