A couple of years ago I attended the mixing session of a TV commercial. Naturally, the agency's representative wanted more punch in the vocals, and the sound engineer decided to "give space" to the mix by introducing out-of-phase elements. I must admit that in the controlled environment of the studio the mixture sounded good. When reviewed in a stereo receiver it was passable, although somewhat confusing. But when heard on a 20" monophonic Korean TV, the mix was reduced to a lonely voice over a murmur of music and effects with the occasional blow of cymbals overshadowing the voice of the announcer.
The sad thing about it is that this happens to us every day. For practical purposes what our monophonic users hear is the passive mixdown of a stereophonic mix that in most cases does not take into account the limitations of the significant portion of the audience that continues to listen to us through a single speaker.
When more is less
How do DVD discs sound with Hollywood hits on a 14" monophonic TV? Usually not very well. When the powerful mixes that make theaters rumble are reduced to a monophonic track by a 4-cent integrated circuit, they lose quite a bit of strength. That's why Hollywood makes the effort to include 2.0 mixes in most commercial titles. But as all enthusiasts know, the vast majority of consumers don't take the trouble to select the audio that suits them best when they start watching a movie, and the work of mixing it finally does the DVD player or the TV.
I think we can be sure that our migration to surround sound will not include the realization of additional 2.0 mixes for the benefit of some viewers, plus most likely in the real world we will not be able to count on mechanisms to transmit them. Then we can assume that in the coming years only some of our spectators will begin to enjoy the immersive result of our efforts in their home theaters well or poorly installed ... while most will continue to listen to mixdowns of our products, either in stereo or monophonic.
What we will hear at home in these cases is the passive mixdown (or with preset processing) of a good 5.1 mix, which usually has an excessive dynamic range for what the normal viewer is used to hearing from their TV; Remember that we have accustomed our viewers to overprocessed broadcasts that are like a continuous series of screams, which will make that mixdown for the average viewer just sound very loud at times and somewhat confusing most of the time.
And to complicate matters, some of them will begin to resort to the unpredictable surround sound simulators that have begun to appear in stores and telesales programs promising miraculous results if one buys them right now...
And now we are six...
How to handle our surround sound? Basically making well-made mixtures. X.1 mix experts make a basic recommendation: Rear speakers should only be felt if they disappear. The importance of the spatial projection of sound effects is evident, but the exaggerated use of additional channels will generate greater sound pressure of music and effects in a hypothetical stereo mixdown , which for an unsuspecting user is synonymous with noise.
The more surround we put to the mixes, the more the dialogues of the central channel will be "dirty" when "going down" to stereo. And when misunderstood creativity crosses the path and voices begin to appear on the rear channels or the bass is reinforced so that the subwoofer "makes itself felt", we will begin to generate scenarios in which the common viewer will not want to continue with our programming because the voices will not be understood.
Apart from the aesthetic conditions of the mix, the realization of programs with multichannel audio presents an interesting variety of new technical problems. A careless handling of signal processing can generate very noticeable inconsistencies in apparent loudness. The phase problems that plague our stereophonic mixes can cause unpredictable effects on surround audio platforms – absurd effects like one sound "covering" another, for example.
In extreme cases, exaggerated equalization adjustments or indiscriminate use of reverb effects can lead to significant spatial distortions... the list of potential problems is endless.
And while we apply the saying that "spoiling you learn", our audience is becoming more competent to evaluate the technical quality of the audio we deliver. More than ever we depend on the ear and toys of our viewers, who also can't help but compare our work to the wonderful mixes of DVD discs they listen to every day.
To conclude in a stark way the situation is this: If our people sometimes get entangled in handling two channels we should make sure that they are prepared to handle five or six competently.
Other problems...
From a transmission point of view, the migration to surround sound can be reduced to a number of technical issues. An operation that only needs to passtrough finished parts – such as a movie or music video channel – should only make sure that the channels are routed correctly and perhaps process them slightly to ensure uniformity of on-air levels. Although if we are responsible people perhaps we should also set up a platform that allows us to ensure the quality of the originals that we broadcast...
Serious problems arise when we study things from a production perspective. Do we know how to do live surround audio? Those who assume that it is enough to have a large console to get out of the way are on their way to a catastrophe. I think I can properly state that it is not possible to use the auxiliaries of an 8x4x4 stereo mixer to generate the rear channels of a decent surround mix...
Other important topics: How to do microphone work for surround sound? How are news handled in surround? How to validate a monitoring system? What are the legal aspects of using licensed processing systems? (remember that Dolby is a brand...) And finally, the most important question of all: How are our viewers hearing us?
The real problem we face is learning how to handle surround sound while making sure that any viewer in front of any receiver hears us reasonably well. This time it is not about learning based on the study of engineering principles. To achieve a successful migration we must study engineering practices , which are perfectly documented in the reference publications of SMPTE, NAB and EBU, among other entities.
So what should we do to ensure good quality and enjoyable surround audio for our viewers? Study. Study hard. Learn from colleagues and competitors And I would say watch a lot of TV.
And speaking of watching TV, let's go back to the story of the beginning. Some time after the mixing session we were talking about a while ago, I had the engineer in question listen to his commercial on a restaurant TV, and he calmly told me that he wasn't worried about the commercial sounding bad on a cheap TV. According to him, the only important thing was that the client left the studio satisfied, and that after all the owners of cheap televisions do not buy the vans in his ad.
The character was a little upset when I reminded him that during a 30-second commercial the viewer can change channels five to ten times. And that the customer can get angry if your commercial sounds bad; in fact you may not want to pay for airtime. And our naïve engineer cut the topic saying that this was not his problem, that it was the business of each channel. And he was absolutely right: It's our problem.
