Dolby Atmos is a brand-new cinema audio platform developed by Dolby Lab, which was released on April 24th, 20 12. It breaks through the traditional concepts of 5. 1 and 7. 1 channel, and can present dynamic sound effects in combination with movie content. Different from the previous audio signal to control one speaker in the cinema to emit the same sound, it can make multiple speakers on one side emit different sounds one by one, creating a more realistic sound effect from far and near; Loudspeakers are added to the ceiling, surrounded by sound fields, and more sound details are displayed to enhance the audience's viewing experience.

2. The origin of the development of panoramic sound:

Before understanding Dolby Panoramic Sound, it is necessary for us to understand some common sound formats before it. Looking back at the sound evolution history of movies and cinemas, it starts with mono, then stereo, then surround sound, then 5. 1 and 7. 1 channel. Theoretically, the next channel will be 9. 1,1.6546436.

Mono: There is only one speaker in the middle position behind the screen, hence the name Mono.

For example, the old TV set used to have only one speaker, and that was mono.

Stereo: On the basis of the former, the mono center speaker is expanded into two speakers (earth tone) which are symmetrical to each other, thus becoming two channels, hence the name stereo.

Surround sound: On the basis of the former, a set of speakers (purple) are added at the sides and back of the auditorium to make the sound really surround the audience, hence the name surround sound.

5. 1 channel: On the basis of the former, the surround channel is divided into left surround (blue) and right surround (pink), and a subwoofer is added in front of the screen. To sum up, there are five channels: the center channel of the screen, the left and right channels of the screen, and the so-called bass channel with 0. 1 channel, hence the name 5. 1 channel.

7. 1 channel: On the basis of the former, surround channels are divided into four, namely, left surround (blue), right surround (pink), left rear surround (yellow) and right rear surround (green), which is 2 channels more than 5. 1, hence the name 7. 1 channel.

3. The necessity of introducing Dolby panoramic sound.

Although the sound format has changed so much, from the feedback of filmmakers, these changes and progress are still not enough.

Figure 1

Figure 2

As shown in Figure 1 and Figure 2, in the 5. 1 channel, if the moving effect of helicopter sound is to be realized, the sound is either in the right surround area (Figure 1) or in the left surround area (Figure 2), that is, jumping from one side of the theater to the other, which is not a real moving effect.

In the 7. 1 channel, the sound of the helicopter goes from right to right, then to left, and finally to left (that is, the sound is emitted from pink, green, yellow and blue speakers in turn), which realizes the effect of sound movement, but it is not accurate enough.

Later, Dolby Company tried 9. 1,1.1,13. 1 channels, but the increase of channels was only quantitative change, and it could not bring qualitative change. In fact, as early as 1953, Harvey Fletcher, one of the greatest reformers of early film acoustics, said that what matters is not how many channels there are, but to make people feel that sound is everywhere. However, the sound solution based on sound channel can't satisfy the filmmaker's desire for more precise control of sound, nor can it completely make the audience feel the omnipresence of sound. Therefore, in this case, it is necessary for Dolby to introduce a sound format that is essentially different from the past, that is, Dolby panoramic sound.

4. Characteristics of Dolby Panoramic Sound

(1) First of all, Dolby Panoramic Sound is based on sound objects, unlike sound solutions based on sound channels. For example, the sound of a helicopter in a movie can be regarded as a sound object. When the helicopter flies on the screen, its sound will pass through the speakers on both sides and behind the audience in turn, achieving extremely accurate and smooth sound movement.

The helicopter sound will be emitted from these four speakers in turn, forming accurate and smooth sound movement.

(2) Secondly, Dolby Panorama installed two sets of speakers on the ceiling of the cinema (above the auditorium) to simulate the sounds coming from above, such as helicopters hovering overhead, thunder, rain and so on. This kind of overhead surround sound is lacking in previous sound systems. After adding the sound field overhead, the sound field around the audience is truly realized, and the audience is immersed in the film.

Dolby Panoramic Sound System adds two rows of speakers above the audience's head, which truly realizes the sound field around the audience.

(3) Generally, cinemas are very wide, so the speakers on both sides of the wall must be installed in a very high position, which may give the audience the illusion that the sound passes overhead. Therefore, in a 5. 1 channel cinema, the illusion of overhead sound will only occur when the audience sits in the middle of each row of seats and the speakers on both sides of the wall emit the same volume. If you slightly deviate from the middle seat, this illusion will disappear.

The overhead speaker can not only give the audience a better sense of overhead surround, but also accurately locate the position of overhead sound, achieving some very complex and delicate effects. For example, in The Hobbit: An Unexpected Journey, in Gollum's cave, they used reverberation in the overhead speaker, which made the audience feel as if they were in a cave. Not only that, the director also wants to show the sound of water dripping on the top of the cave, and the sound of water dripping in different positions is emitted by the overhead speakers in the corresponding positions.

5. How are the speakers of Dolby Panoramic Audio & Video Hall arranged?

In order to study this problem, Dolby chose a cinema in San Francisco and closed it for six months for research. The research department can place speakers anywhere in the cinema, and the ceiling and walls around the auditorium are covered with speakers. They did a lot of tests, including blind tests, to determine how the speakers were arranged, and reached a decision to arrange two groups of speakers above the audience's head and drive each speaker separately.

Every cinema is different in shape and size. In the actual layout, the theater will provide a structural sketch of the theater, and then Dolby will evaluate it, and then feedback it to the theater, telling the theater where each speaker should be placed, and then Dolby will send engineers to the theater to install and debug the speakers.

In addition to the speaker layout adapted to local conditions, Dolby's panoramic sound system is very intelligent. Dolby panoramic sound decoder in the cinema stores three-dimensional spatial information of the cinema, such as length, width and height, so it knows the terrain of the cinema and the position of each speaker. When mixing gravity, he moves and places various sounds in the mixing shed according to the spatial information of the mixing shed. Although the cinema is bigger than the mixing shed, the decoder knows how to reposition the sound correctly through the algorithm to adapt to the size of the cinema.

Dolby panoramic sound cinema

6. Where is the best place to watch Dolby's panoramic sound movie?

When watching IMAX movies, there is a debate about choosing the best cinema and the best seats, and there are many strategies in this regard on the Internet. No matter which Dolby panoramic sound theater the audience goes to and which seat they sit in, they can get a better Dolby panoramic sound experience. People generally like to sit in the middle and watch movies to get a sense of visual immersion. In the previous 5. 1 channel cinema, if you sit next to it, your auditory experience may not be as good as that in the middle, but in Dolby Panoramic Sound Cinema, even if you sit next to it, your auditory experience will be greatly improved, because you can feel the sound moving. Therefore, in Dolby Panoramic Sound Cinema, you don't have to sit in the middle just in terms of auditory experience, and the auditory effects in other areas outside the middle are better than before.

7. How to improve Dolby panoramic sound?

As mentioned at the beginning, Dolby panoramic sound first appeared in the movie Legend of Courage in 20 12, so it is still a very young technology. Dolby constantly carries out technological innovation and conducts various researches in the United States, Europe and China. He mentioned that there used to be a sound format, Sensurround, which simulated the sense of earthquake, and it was used in the movie "Earthquake" of 1974. If the director needs it, Dolby can add more low frequencies to Dolby's panoramic sound to simulate the effect of the earthquake. Some people even put a speaker under the cinema to let the sound come from below, but this is difficult to achieve in commercial cinemas because the audience's drinks may spill on the speaker below. He stressed that some cinemas put subwoofers under their seats, but this is the personal choice of the projectionist, and Dolby should meet the needs of filmmakers.

At the same time, in Disney theme parks and other places, speakers will be hidden in seats, and future cinemas may also put speakers on seats to create various effects. These ideas are all possible, but it has also been pointed out that Dolby's current goal is to promote Dolby panoramic sound as much as possible, and Dolby cooperates with cinemas, hoping that more cinemas will install Dolby panoramic sound system; On the other hand, they should also find ways to meet the needs of film creators and help them tell stories better.

Dolby Panoramic Sound is a young technology, which was originally applied to larger media, such as movies, and can now be applied to smaller media, such as home theaters and tablets. Not long ago, Paramount released the world's first Blu-ray disc "Transformers 4: Extinction and Rebirth" with Dolby Panoramic Sound. In the future, we can try to use Dolby Panoramic Sound in broadcasting.

8. Dolby panoramic sound and traditional mixed recording method

Dolby's panoramic sound not only changed the cinema and the audience, but also changed the mixer. Skip Lievsay not only won the grand prize for Gravity, but also was the director of sound effects and editing for the Cohen Brothers. His famous works include: Simple Blood, The Color of Money, The Age of Innocence, Doing What You Should Do, The Silence of the Lambs, etc. Skip also recently co-produced The Hunger Games: A single spark can start a prairie fire and The Hunger Games: A Dream of Freedom. Skip believes that Dolby panoramic sound is an extension of the existing mixed recording technology, and it is not so much a brand-new production tool as an improvement of the traditional original mixed recording method. Skillful use of traditional mixed recording tools enables Skip to quickly apply Dolby panoramic sound to produce more complex and detailed movie sound. On the other hand, even if the mixer doesn't do much work, the sound released by Dolby Panoramic Sound Cinema is very fidelity.

9、5. 1 & amp； 7. 1。 Dolby atmosphere

Skip thinks that from mono to 5. 1 channel is a qualitative change, and from 7. 1 to Dolby panoramic sound is also a qualitative change, and the sound has changed qualitatively in detail and fidelity. Skip thinks that 7. 1 is a bit between 5. 1 and Dolby Panoramic Sound, which is also his favorite format. He likes to be able to locate the sound with so many points in the cinema.

10, which films are suitable for Dolby panoramic sound?

Gravity was recorded with Dolby's panoramic sound, and won all the Oscar sound effects awards, including the Oscar for Best Sound Effects. There are many impressive long shots and lens movements in the film, which can reflect the precise sound movements of Dolby Panoramic Sound. Skip also thinks that Dolby Panorama is an excellent tool for making gravity, but he also thinks that almost all movies can at least try to use Dolby Panorama, and almost all movies can benefit from Dolby Panorama's high-fidelity sound effect and sound moving with the camera, so in his view, Dolby Panorama is actually a tool suitable for almost all movies.

Not only commercial films such as Gravity, but also literary films such as Return use Dolby Panoramic Sound.

1 1. How does sound affect the audience?

The main source of information for the audience is visual information. Compared with vision, sound usually affects the audience in a more subtle way at the subconscious level, but Skip also points out that sometimes sound can be less subtle or direct. Take light for example. Light is a very subtle visual element. The director can use light to help the audience understand the film. Light and sound have something in common.

12, how does Dolby's panoramic sound affect the audience?

Skip takes gravity as an example. He pointed out that sometimes the music inside is very bold. There are many small parts floating in space. With bold and loud music, it brings some drama to the camera, which makes people feel unexpected. Now, due to the existence of Dolby panoramic sound, Skip can put some very subtle sounds and sound actions on the sound stage to increase the sense of detail and realism of the picture, and add subtle gradients, similar to the changes of light and picture in movies.

13, will Dolby Panorama usurp the role of the host?

The original intention of introducing Dolby panoramic sound is to make the audience feel more immersive and better enter the story, but like any new technology, it may be counterproductive if used improperly. As a sound mixer, Skip should ensure that Dolby's panoramic sound is not too eye-catching, so as not to distract the audience from the story. In Skip's view, all efforts are made to make the film better, so that the audience can enjoy the film better and satisfy the directors and producers. This is sound mixer's main responsibility. Dolby's panoramic sound may indeed be overdone, for example, it is too loud, and sometimes sound mixer or a director with a technical background shows off his skills in the sound. However, Skip also stressed that from an artistic point of view, artists should not be restricted from using any tools, just as red is not allowed in the process of painting just because it is too conspicuous, so this restriction is obviously inappropriate.