PART ONE: Understanding the basics & getting organized
By Patrice CONGARD
Patrice Congard is a partner in the French company Anagram Acoustics, and a fanatic of sound like you won't meet everyday.... A sound enthusiast since his early days, he graduated from the Sound & Vibration Research Centre after studying at Southampton University.
He spent the following years involved in several Audio / Video specialized companies, including : France Acoustique, Patco & Vel, Atelier 33, L-Acoustistics and Avance Technologies. Longing for more freedom in his work, he created Avance Engineering in 2001, a company specialized in the design of acoustic products for Home Theater and particularly acoustically transparent projection screens (Wingscreen, Wingspeaker, Soundscreen) before becoming partner in his current venture where you can see his latest Auditorium in our Special Report Anagram Acoustics home video showroom. Due to his broad experience and technical knowledge in the fields of sound and image, we are happy that he has chosen CineNow! to write this series to bring you his insight and help our readers learn how to get the most out of their Home Theater system while avoiding the headaches.
You will be able to check out his articles here where, week after week, he will discuss, with his sense of humor, his views on Home Theater sound and image technologies in our columns and step by step help you avoid the pitfalls in your choices. You can write to him your thoughts, patrice.congard@anagramme.fr
Patrice Congard : The Home Entertainment environment, the perfect marriage of sound and image technologies, is a young market and thus the area where the greatest potential for innovations resides. In addition, the Audio / Video Market is the fastest growing segment in Consumer Electronics, which means, economically, that this justifies investment in innovation.
INTRODUCTION
What I heard one day at a Trade Fair:
About three years ago at lunch in the cafeteria while I was exhibiting on a stand at the High Fidelity & Home Theater show at the CNIT, my attention got caught by a conversation between two exhibitors of the nearby computer trade fair:
- “There, I just finished setting up my multimedia computer, it works great. I’ve added a 5.1 audio card for the DVD, then I’m gonna get a Home Theater …”.
- “Are you insane? Home Theater is crap, it just don’t work”.
I almost choked on my sandwich before inviting this impertinent person two floors below, so he could see and hear what a real Home Theater is supposed to be like.
Then, I decided otherwise: after all, maybe he was right. On this show, more than 75% of the installations exposed were far from convincing, although such presentations are supposed to highlight the equipment’s qualities. Let’s imagine a Home Theater installation simply shaped around the management of a retailer’s own stock or worse: around the client’s wife’s decoration tastes. After a closer look, one must admit that the reasons why a Home Theater won't be satisfactory are so numerous that very few of them can escape it.
Nevertheless, when a system works, it is magic! So let’s go back to the beginning, shall we?
What is cinema?
Without conducting a historic research of Cinema, we can simply say that “cinematography” is what allows fiction to look like reality. A book or a story are fictions which appeal to one’s imagination ; so is theater in a lesser measure, since it imposes scenery, but it never claims to give the illusion that the fiction is reality.
At the very beginning of Cinema, then mute, a room emptied its spectators, panicked by the arrival of a locomotive charging at them, even though the special effects were far from being what they are today.
The main technical progress of cinema in the 20th century was the addition of sound. Associating sound to the image for films created an unprecedented capacity to create illusion. The technique of sound in cinema caused live shows to be coupled with sound too, which led to the development of… high fidelity. That’s something to remember. But it’s still an illusion and not reality: The impressive rumbling of powerful spaceships always gave chills to an audience, from ‘Alien’ to ‘The Fifth Element’ (remember the hissing tires on the flying cabs…?)
But it’s enough to know that sound is only a vibration of air to understand that, as mighty as it might be, a spaceship will never make any sound in space! And other sound effects, such as dialogues, must necessarily be realistic to sound genuine : If none of us has ever heard a spaceship or a nuclear explosion (or very few of us), everyone knows what a voice, a car accelerating or rain falling do sound like.
That’s when the sound engineer’s creativity is focused on realism and not on illusion. This sort of realism is based on the coherent perception of sounds. At this point, cinema is limited to co-ordinate the two leading senses of human perception: hearing and sight. From this point of view, putting them in perfect coherence and synchronizing these senses is a powerful mean of illusion. Still, rather naïve were those who ran away at the sight of a silent black and white locomotive!
Such illusions allow the audience to get into the action, and stealthily forget they’re simply sat in a theater. But such a craft requires technical means and some “savoir faire”, both focusing on the coherence between the sound and the image, a key element for a show’s credibility.
Cinema in public theaters:
Public Theaters have evolved by stages. Once very big at the beginning of the 20th century, they ceased being silent only in the 30s. The sound source, then monophonic, was mainly used and intended for dialogues. It was thus placed in centre of the screen, behind it so it would remain invisible. A multitude of small holes were drilled in the screen fabric to allow the sound to pass through, and remained invisible to the audience’s eyes from the distance.
In these years, sound was the most innovative technique and the main focus of the industry. Colour was the next step in evolution a few years later and inverted the trend: the improvements of the picture had become everyone’s priority, and sound, still monophonic, ceased to evolve. That’s when the size of the screens started widening, first with a 16/9 ratio, then with cinemascope.
Gradually, the sounds used for cinemas were outstripped by those used for live shows and domestic hi-fi systems. Cinema itself evolved into a more intellectual kind of entertainment, focusing more on the authors’ creations than on visual and sonic effects. Theaters grew smaller and more intimate, and the notion of spectacle became secondary. Movies such as “Alien” were amongst the first to inverse this tendency and imposed an important innovation : The use of lighting coupled with sound was to provoke emotions (like today) rather than atmospheres (like Hitchcock). Blockbusters were back in force, but the sound techniques had remained the same since the 50’s. Furthermore, most of the world’s theaters were only equipped with a single Altec “Theater Voice” speaker, or a lame duck copy in most cases.
Nonetheless, the Dolby® company got down to the task and created a stereophonic sound system to be used in cinemas, still integrating a central channel needed for the dialogues’ realistic restitution. But equipment followed only slowly. After “Star Wars”, theaters started to equip themselves with a stereo system, but to a minimal cost. At the same time, the benefit of adding a subwoofer (which name dates the film “Earthquake”) was revealed.
Current sound system configuration in theaters.
A few years before, the late Stanley Kubrick had broken new ground by requesting to personally visit each and every theater playing his film “A Clockwork Orange” to check out the technical conditions of projection before giving his approval. Already a better businessman, George Lucas used this idea a few years later, this time by imposing extremely precise specificities needed to obtain the THX® quality label. The conditions of this very precise contract covered every aspect, from the blueprints of the speakers to the nature of their very own components. As for the active crossover, it was supplied and rented by Lucasfilms.
Sound was once again the high point of the entertainment, and while the techniques finally caught up with those used for live shows, proper creation was devoted to the joy of special effects. The quasi simultaneous control over the digital encoding of a film’s sound on optical medias, and of the digital treatment of the image (“Jurassic Park”) brought tools that still seem to be technically limitless to filmmakers. And even though we still don’t grasp all the consequences, the digital broadcasting of films will have (and can we still say “films”, since it’s now only video?), we can bet this evolution is far from over.
The domestic adjustment doesn't go too well...
Aside from the impressive evolutions in the world of cinema, we can’t but be afflicted when confronted to the derisory appellation “Home Theater” of a TV set (yes, sure, it’s in 16/9, 100Hz, with a flat screen, progressive scan , surrounded by two hi-fi column speakers spaced out by 3 meters, below a small plastic box you’ll want to call your “central channel”, and 2 rear speakers , hum, “surround” speakers of the size of a pack of smokes hidden behind your couch.
The proud owner will, of course, give you a demonstration by switching on to CBS right on time for the news flash. He’ll start his DSP and you’ll soon find yourself confronted to the weird impression that Dan Rather’s voice was recorded inside a cathedral. Great, isn’t it?
Unfortunately, this caricature isn’t far from the truth. I don’t mind people who want to enhance the sound of their TV, but please, keep the word CINEMA out of this sonic mess. Remember, the expression “Home Theater” or "Home Cinema" implies a use for Cinema. Or at least it did, before the manufacturers got hold of this expression. To my understanding, it really means one will feel like in a cinema in his home. Or will he…?
Just for the sake of it, let’s try the extremely audacious hypothesis that a Home Theater is supposed to have something to do with cinema in a domestic context. Now, let’s examine the case of Home Theater sets pretending to equal a theater’s quality in your home, therefore, using a video projector and a “big” screen. And let’s assess the common points and the differences:
The reality of today’s Home Theaters is that sound and image are treated like two distinct entities, stuck up to their own past: Sound is for hi-fi, image is for video (VHS on TV, camcorder, etc…). Due to cultural or other reasons, the audio/video techniques employed in Home Theaters firmly ignore the main point of the concept: a cinema in your home.
I wouldn’t be surprised to hear about the proposition of an installation involving a room optimized for the image, and a separate room conceived for the sound, even from a good salesman. And he might even find a buyer… Having said that, if you find the idea attractive… Skip the rest of this article!
The culprits:
- The journalists:
Journalists are guilty of influencing the opinions of their readers with articles or opinions that aren’t always founded, verified or impartial. I, for instance, am writing these very lines with a very precise idea on how a Home Theater is supposed to work. Am I an impartial journalist? Certainly not. The only thing I can affirm is that a Home Theater isn’t worth its name unless it gives its owner the same sensations he’d feel in a real movie theater, but in a domestic environment. I may be asking for a lot, aren’t I…?
- The retailers:
Retailers are guilty of selling exactly what their clients are asking for, which is simply scandalous. They should chose to close down the store, or even kill themselves if they’re childless. (Yes, these are hard times…), rather than agreeing on selling any of their products to their ignorant customers. Especially because, as we all know, these products never work, do they?
- The customers:
The customer is king, everyone knows it, especially him. But sometimes, the king is bare, or rather misinformed. Maybe he read too many specialized magazines, or maybe he ingested too many technical descriptions of the hippest stuff. But he missed the two points of a Home Theater: cohesion and installation.
- George Lucas.
He’s just the highest priest of Home Theater. True, he brought some common sense into sound in cinema, and his word didn’t go un-noticed, as many theaters updated their sound system even without following the THX® way. But when it comes to Home Theaters, there’s still a long way to go. We find several good articles by Tomlinson Holman (big boss of THX, before he slammed the door and was replaced by Laurie Fincham, ex-director of KEF, who jumped on the occasion to get a golden retirement) which explains why the sound and image desperately need to be perfectly synchronized, coherent, etc… Only one article, dated from November 1989 in the Japan Acoustical Society journal, clearly explains (in Japanese) that the center speaker must be placed in the middle, behind an acoustically transparent screen. We shall note that the other articles from the JAS are not accessible to the main audience, even to those who speak Japanese… Other publications were skillfully written: the coherence between image and sound is only described as “preferable”. They certainly wouldn’t want to cut the hand that feed them, a.k.a. 90% of the customers, who are using a soundproof screen with three speakers around it.
- Your mother-in-law:
Because it’s always good to unwind. And since your mother-in-law is constantly wrong (I don’t know about yours, but mine really is!), she probably deserves your wrath anyway.
The typical profile of an installation that “doesn't work”:
The system is in a dedicated room, in the basement. Probably just a room that didn’t have much use anyway, with a low ceiling, a rectangular shape, and no windows. All in all : perfect. As it will only be used for your Home Theater, no need to furnish it. The irregular brick walls are covered with a white filler to look clean and lean, and you install your system in the length of the room. At first, you’ll chose a video projector with at least an XGA capacity, since you think you know your way around a computer. The luminosity / price ratio is a decisive factor in the purchase. To project the picture, you’ll need a proper screen as you’ll feel the wall is a little too rough. You’ll chose a screen that rolls-up, electrical, and also quite big while you’re at it, so when you’ll be done using it, you’ll be able to roll it up and hide it (which is mandatory is a dedicated room…).
Then, you’ll need a surround sound, so why not taking the old stereo down from the attic this should do for the two main speakers. The only thing missing is an integrated amplifier. This way, nothing will keep you from listening to the radio inside your dedicated room…. And since you’re able to get a 5.1. sound, you’ll need a central speaker, like a "d' Appolito” (and where to put it if not on the floor, below the screen, for lack of an available support), two not-too-expensive surround speakers, and a Subwoofer. How cool : after many week-ends spent wiring the whole system, you’ve managed to make the image fit on the screen. Well, all right, this does not feel like a real cinema… but still it’s a Home Theater. And if you still watch TV more often in the dining room, it’s because you watch TV more often than you go to the movies.
Let’s see what went wrong….
The screen’s size:
Even though size shouldn’t matter, it actually is a determinant factor for your Home Theater : The size of the room, the rest of the equipment, and therefore the budget.
TV aficionados will likely tend to go for a too small 4/3 screen, while movie lovers will go for a 16/9 screen as large as their room will allow. At the end of the day, none of them will be satisfied, but neither will question his own choice. Two examples of what you shouldn’t do:
- The wall which will host my screen is 15 feet wide. Since I like a big image, I’ll chose a screen that’s about 15 feet too ….
- I long for a image as detailed and contrasted as possible. I will the chose a 50 inch screen, which will still be much larger than my current TV.
Both of these approaches have a weak point in common: They don’t take into context, the environment or the other elements of your Home Theater under consideration. In both cases, you will be disappointed.
The position of the speakers:
You can’t go wrong on this, let’s just do like everybody else does: We’ll put two “main” speakers on each side of the screen. If the screen almost fills the wall’s width, what the hell we’ll put them in the corners.
Home Theater - 5.1 configuration.
Then, we place a small central speaker below the screen, like a pseudo-d’Appolito (with a too high crossover frequency to work as a real d’Appolito there are plenty of those on the market). Make sure the height difference between the main speakers’ tweeters and the central speaker doesn’t exceed 25". (By the way, who is the idiot who imposed this on us? What exactly did he base his ignorance on?). This being said, it could be worse: we could have already put the central speaker directly on the floor… To complete our installation, let’s add a subwoofer in a front corner of the room, and two surround speakers on the back wall. This results into a Home Theater identical to many others. That’s Home Theater Cloning, but let’s not worry: the others don''t work properly either. Yes, true this sound system gives you a rather spatial sound, and delivers good base. A lot of base, actually, with some redundancies, some lagging and some very special effects never intended by the original sound track.
The main speakers deliver a slightly hissy sound, with some prominent trebles.
The central channel delivers a rather coloured sound, with a definite lack of intelligibility on dialogs. To improve upon this intelligibility, you can increase the level of this channel, but the result will quickly end up distorted.
But the rear speakers are "really" present, and you distinctively hear when a sound goes from the front to the back, even though it is not totally coherently smooth and doesn't really sound the same…
The set-up of the room - the initial, yet fundamental decision to need to make
I read an article somewhere claiming to turn amateurs into proper Home Theater installers "1-2-3", with drawings describing the “how-to”. The first step was the choice of the axis of the room. A Home Theater was drawn with its diffusion directed to the room’s length. The caption below the drawing simply read “Yes”. Next to it was a similar drawing with the axis of diffusion directed to the room’s width, tagged by a huge red cross. The caption read “No”. I have no idea what made this journalist so opinionated : I see a multitude of problems that can cause a Home Theater to be misplaced when placed facing the longest run of the room if its dimensions aren't too big, for example, the main speakers might be too close to the walls and cause some deep unevenness in the bass & low-midrange frequencies...
Furthermore, the short reflections (< 10 ms) (thus on nearby walls) are particularly advised to be avoided in sound diffusion: As they are not perceived as elements of reverberation of the room, they are mistaken with an lack of coherence of the sonic source, and greatly reduce the intelligibility. And if the walls are of a clear color, reflections of light can also affect the image. So many problems that can eventually be avoided by placing the system in the width of the room.
Another frequently met problem is the location of your Home Theater in an odd spot, only because the current position of the rest of your furniture prevents it from being placed elsewhere. For heaven’s sake, consider the possibility of moving your furniture before taking a decision. I have seen screens half hidden under a staircase, with its opposite border in contact with the angle of two walls. I have also seen skewed screens. And that’s without mentioning the many asymmetries. This can be solved with the appropriate acoustic treatment, and if you’re in this case, you absolutely should do it.
Globally, the problem is that the users conceive the place allotted to their Home Theater themselves, without the necessary knowledge, and then furnish their interiors. And then only will they acquire their equipment. In most cases, so it can correctly function at this stage, one would need knowledge, imagination, and an extra budget which you wouldn’t have to spend if things had been done in order.
Where is that remote control?
More or less, your new system is finally set and it’s time for your first family showing: the moment of truth. You turn the lights low, place a DVD in the player (after squatting to reach it, as it is stored in a low piece of furniture with all the other devices), and you hit “Play”.
The DVD’s menu appears. Bummer, you need the remote control that’s on the table behind you, in the dark. There it is, you’ve found it. Since it is not back-lit, you need to turn on the light in order to use it properly. There, you start the film, it’s all good, you can switch off the light.
The film starts, but there’s sound is only coming out on two channels, while you were hoping for a 5.1 sound. On top of that, the image is deformed by an "anamorphism" or just won't fit the screen.
All right, you need the projector's remote control to switch into 16/9, and the processor's remote to switch the source into “Digital Auto”.
Do your thing, turn off the light again, re-start the film…. And where’s the sound?
Obviously, the DVD was pre-set into PCM. And where’s the DVD remote now?
It gets particularly pleasant now that your brother-in-law start putting his nose into it and insists that you should “definitely check out the speakers’ wiring”.
Good luck to you…..
CONCLUSION
There are many more reasons why a Home Theater will not work than the other way around. But when it’s working, what a thrill it can give! Confronted with a system integrating multiple sound sources, video projection, some switching, and pure acoustics, you’d better keep an open mind and know what you step into to not mess it up. The first thing to do and many try to avoid it (how wrong they are!) is to think!
As we said at the outset, many different subjects will be covered here in coming weeks such as: video projection, acoustic speakers, electronic sources, etc… so keep posted !