Design & Best Practices: Part 1

Video Transcript

00:08
Today we're going to make you aware of some basic design guidelines and best practices when working  
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with QSC cinema products. That goes for both commercial cinemas and systems installations  
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that call for cinema-like experiences. Let's do it!
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This training is for systems integrators and technicians with an interest in projects that require a basic level of cinema knowledge,
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and also for cinema dealers who want a refresher. We'll go over room design and acoustics,
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loudspeaker installation, aiming and wiring, room tuning and equalization, and then we'll break  
00:44
down the Best Practices of a 7.1 audio system design that uses Q-SYS as the audio processor.
00:52
The principles we'll cover today are not just for commercial, DCI-compliant, movie theaters.
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They can also help optimize the sonic experience whenever it's used to support a visual experience,
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from a university auditorium, a museum exhibit, or actually any multi-purpose venue where you want  
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to create a cinema-like experience that has a produced, multi-channel sound source.
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Throughout this course we're going to reference documents and charts that we might not cover in depth here but we've  
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added them to the Links and Downloads section for your convenience. So whenever you see this icon  
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just think of it as a special little surprise waiting for you to open and enjoy.
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The primary difference between true Cinema applications and  almost any other type of project in the pro audio  
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or AV world is the idea of translation. Translation of the artistic intent of the content creator.
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With normal music recording, no consumer will ever hear the music the same way that it sounded  
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when the recording was produced. The creator can't control where it will be listened to, what kind of  
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equipment or settings they will use - there's just too many variables. But that's not the case with  
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movie theaters. The function of a movie theater is to recreate what was heard on the dubbing stage  
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when the film was mixed. We call this "translation". To assist with this process cinema standards have  
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been developed over the course of the last 100 years or so by organizations like these,
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that govern areas like loudspeaker selection and placement, installation practices,
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sound pressure level targets, a very specific sound measurement process, and a well-defined acoustic environment designed to take the "room" out of the mix.
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These same standards are also used to design the dub stages where films are mixed. The extent to which these standards are followed determines how close
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the translation is. So what exactly is good cinema sound? And why is it so important?
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Well, we've already covered "Translation". Next is the removal of coloration of the sound source. The audio system should be neutral, and the room should have as little
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impact on what we hear in the audience as possible. Dialogue is king - if the actor's voice is not crystal clear, you've missed the mark.
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Even and balanced coverage is critical. Everyone pays the same price so everyone should get  
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the same experience right? And finally never ever distract the audience's attention from the screen.
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This means that the sound should be localized to the image on the screen, and there should be no  
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audible echoes, or rattles and noises in the room. The whole point is to not break from the illusion.  
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So how do we get "the best sound system" for an application? We start with the room itself,
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the sound system design and the components of the system, and the system installation.
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Getting any of these wrong can make the best gear in the world sound bad. But getting them all right will  
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get you the best sounding audio system possible for a cinematic experience. First let's focus on  
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the room. Good sound (and image for that matter) in any space starts with the Room. The size and shape  
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of the room, and its acoustics are two of the most fundamental issues, and they're highly interrelated.
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The length to width proportion has an effect on how reflected sound will sum or cancel in the room.
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A room with equal proportions is probably the worst shape, followed closely by long, narrow rooms.  
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For both acoustics and image, the best room proportions are between 1.2 to 1 up to 1.5  
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to 1 length to width. For example, a minimum length for a room that's 30 feet wide would be 36 feet  
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using the 1.2 to 1 ratio. The optimal ceiling height is defined by the length to width ratio,
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according to this diagram. Based on this chart a room that has a ceiling height of around 19 and  
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a half feet and is 30 feet wide would be in the ideal range. Of course sometimes you might not  
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have any control over these dimensions, but if you understand that if the room doesn't fall within  
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the sweet spot of this chart, you can at least have an informed conversation with your client.
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All right let's take a break there, and come back when you're ready!