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Mixing Matters:
Is Surround for Broadcast Worth All The Fuss?
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There are a lot of television channels out there these days. How many? 200? 300? 500? However many there are, having so many channels brings a lot of bandwidth to the table with a lot of programming to satisfy a lot of viewers. The Advanced Television Systems Committee (a bunch of academics and manufacturer’s reps who defined how digital television works) has, with the help of Congress and the FCC, loudly promised that DTV delivers incredible HD pictures with digital surround sound. We all know digital is good, right? The consumer may not have had any say about the abandonment of their old NTSC system and they may have had to purchase new equipment to keep viewing, but the price of DTV receivers is already low and continues to drop.
DTV actually IS pretty cool. One channel can send out multiple programs in multiple languages, for example. Those high-def pictures can be gorgeous with accompanying sound as good as any blockbuster movie soundtrack. Even your local news show can be delivered with 5.1 channel surround sound right into your home for free! In fact, DTV can give you a digital surround mix with a simultaneous secondary language version and another simultaneous Descriptive Video Service. This is one amped up system with a lot of cool stuff and a lot of extra sound channels! Hey, wait a minute. Is it really free? Doesn’t someone have to pay for all of that glorious surround sound?
You Pay to play
YOU get to pay for all that glorious surround sound! You and I, that is. Finishing a program with surround sound takes more time than finishing in stereo. These days, as competition to grab viewer attention heats up, more programs than ever are pressed to deliver surround sound to stay competitive. Broadcasters are desperate for cash. Their primary source of funding, advertisers, are demanding lower rates as their target audience spreads out more thinly than ever before. No wonder, then, that production budgets have been shrinking. Program producers find themselves stretched to deliver more sound with HD images for less money than before. Is surround sound worth the extra cost to produce it?
It is easy to shout, “YES surround sound is worth it!”, but I am not so certain. I AM a sound guy and I LIKE surround sound. It is fun to listen to and fun to produce but let’s look at some realities. How many people currently hear television sound in surround? This is a difficult question to answer. According to the most recent Federal decennial housing census of 2000, there were 109 million viewing homes (approximately 110 million housing units at that time, 99% with at least one TV set). No doubt the number has grown since then. According to an LCD industry marketing group, approximately 60 million flat panel sets were sold in North America in 2007 and 2008 combined. A quick scan of models shows that almost none of them came with surround sound speakers, just a stereo pair of little speakers. We want to know how many surround sound systems are tuning in. Since I cannot find a reasonably trustworthy statistic I am going to do a very unscientific thing. I am going to make a wild guess that 3% of those 109+ million viewer-homes can listen to surround sound when they want to. Some few of them bought a “home theater” setup with actual surround speakers. A few more have gone to the trouble of hooking up their set top cable or satellite box to a surround receiver. Not all of them will have their TV sets turned on all the time, though, so let’s say 2 percent of those surround-ready viewers are actually tuned in. Of them, maybe only half will bother to turn on their TV and surround receiver at the same time. Everyone else will, out of sheer laziness, listen to the pair of speakers built into their sets. Altogether then, by my totally unscientific brainwork, 1 million people will actually hear surround sound when it is broadcast. One percent is a paltry amount, for sure, and probably they are not all watching the same program! Whatever the number, at least a few folks will hear our carefully constructed surround sound so let me ask our original question in a different way.
“How much extra money are we willing to spend to make surround listeners happy?”
Based on their tiny numbers, I imagine not very much. Mind you, I am not about to suggest that we ignore surround sound. The percentage of surround listeners, whatever it is, will improve over time. Viewers, and everyone else, are expecting surround to be there right now as promised. We’re working hard at it and yet so very few will notice or care! We can never ignore what the vast majority of our viewers will hear for the next many years, stereo plain and simple. Actually, a fair number will hear only good old mono, which means we’ll be mixing to satisfy mono, stereo, and surround viewers. Surround is here to stay, extra time will be spent to make it happen, and we have to make the best of it. The solution to this puzzle is simple. Rather than tailor separate surround and stereo mixes we should instead mix for all formats at the same time. In terms of budget vs. time, it is the most sensible approach.
The Downmix Fix
I’ll bet most people do not know how sound with DTV really works. Why should they? You and I, though, need to know. For instance, when we deliver a newly completed show with surround sound, we also deliver a totally separate stereo mix. We already know that more people will hear stereo right now but what is really interesting is that as we go further down the DTV road, there will be less likelihood that anyone will hear our separate stereo mix! To clarify, I am not saying they will not hear stereo, I am saying they will hear stereo but it will not be the stereo mix we provided. Instead, when they hear stereo they will hear a downmix of our surround mix. This is because whenever you tune to an HD channel, there will be either a stereo or a surround mix, not both, whatever the broadcaster chooses to send along with that stunning picture. If the broadcaster is being competitive he will make every effort to send out our surround mix instead of the stereo mix.
When you tune in an HD+surround show on your swanky new flat screen TV, and that blue “surround” indicator light comes on, do extra speakers suddenly jump out of the set to play all the channels? No of course not. The set has only two speakers to play up to six channels of sound with, so it is forced to adapt and downmix those surround audio channels to stereo for its two speakers. We sent the broadcaster a separate stereo mix that would be ideal, but the broadcaster is only sending the surround mix. Fortunately, there is a commonly-used formula for an automatic downmix the set can do. We can use the same formula as we mix to check a downmix of our work and make intelligent decisions that guarantee a good outcome later. For best results there are some rules of thumb that must be followed. If we do not know what we are doing we can easily end up with a mix that sounds good in surround but, when automatically downmixed, can have problems. Even if we do everything perfectly on our end, some sets try to create a surround-like experience with their two little speakers by doing some serious digital manipulation. They alter the balance of channels, dialog may be lowered or music boosted, they hype bass and treble and other tricks to try and convince you their set is something more than it really is. It is kind of hard to predict the outcome.
Did I mention there are two types of surround in use today? It is just one more wrench tossed into the works. DTV is all about delivering surround capability but not all programs will actually have a 5.1 surround mix. There is an earlier surround format that was designed specifically to be compatible with good old stereo broadcasts. DTV would seem to eliminate any need for such a thing but the technology will remain with us for a long time to come if for no other reason than that many thousands of feature films and prime time network shows are already mixed using the format. Our DTV technology is “compatible” with stereo and will send along this format perfectly well. A few earlier programs may be re-released with 5.1 surround sound, but many will not. The reason I am bothering to talk about this minutia is that, your set’s automatic downmix from surround sound can emerge as either this special stereo-compatible surround format (called “LtRt”), or as regular stereo (called “LoRo”). They are not the same, they sound similar but not identical, and the choice of which way your set presents it to you is often a setting buried deep in the recesses of a sound setup menu, if it can be changed at all. Whichever way the set’s manufacturer has decided is “default” is likely how you’ll hear the downmix unless you go geek-style and tweak the settings. We need to make sure our surround show will downmix with good results either way. Egad. I never said this was simple stuff.
“Is surround sound worth the extra cost to produce it?”
Assuming we answer “yes” and plunge ahead, how much extra money are we willing to pay for it? I think there is no good answer. Each program is different. News and “informational” programs can get by with stereo or even mono. The primary advantage of surround sound is to create an “immersive” listening experience. Many programs benefit little, if at all, from a fully immersive sound experience, assuming there is such a thing at home. Dialog is, after all, always or almost always a mono sound. I’ve listened to situation comedies where a disembodied audience laugh track roars out of the surround speakers, which is terribly distracting! No matter what, an ever-increasing number of programs are being contracted to be produced with “surround sound” regardless of content, which means that surround sound is slowly becoming the norm rather than the exception. We’ve got to use those extra speakers even if we do not need them. At the same time, an overwhelming majority of viewers will not hear our programs with a surround sound system anytime soon. Instead they will hear downmixed stereo through the two little speakers in their large screen television.
What is my point to all this? I just want to make you think about some of the things I have to think about. Knowledge is good. Regale your friends at dinner tonight.
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| Mixing Matters is an open-ended series of short, easy-to-digest articles about some of the grey corners in our world of sound mixing for film and television.
©2009 Richard Fairbanks
Do not quote or copy without prior written consent
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