Audio Consultant Magic – Creative Sleight of Hand for Design

As an audio consultant, I’m commonly confronted with unique problems. These days, we have such flexible tools at our disposal to perform “miracles” that just two decades ago would have been considered impossible. Looking up at the fireworks on July 4th, this past weekend reminded me of this. Actually, it makes me of the Arthur C. Clarke quote.

“Any sufficiently advanced technology is indistinguishable from magic”

The irony is that because the public doesn’t understand the complexities of today’s large scale audio deployments, they don’t even realize the sleight of hand. If only sound traveled at the same speed as light, this stuff would be a breeze. Alas, it ain’t so. For anyone following along who’s not an audio geek, this is the reason that you see lightning first and then hear it afterwards.

Sound travels roughly 1,127 ft/s in air. Light travel is instantaneous, by comparison, for most practical purposes. This can cause problems, if you’re trying to keep the two in sync. Picture a mega-church, where the first seat is 20 feet in front of the screen and the furthest is 200’ back. If the audio is aligned with the video at the front seat, you will have slightly over 200ms of delay between the lips moving and the dialogue at the last seat. Can you say “Kung Fu Movie”!?! In a stadium, the furthest seat from the primary LED screen might be 500’ or more away. This is just simple physics.

When everyone files into the stadium, they look up at the gleaming new video board with awe at the image size. You can’t “see” the sound, so it’s taken for granted. Twenty years ago, you wouldn’t be able to understand half of what was spoken, the music would sound like it was coming from inside a tin can, and the volume wouldn’t get loud enough to hear the referee over the noise of the crowd. Nobody stops to think today that you can actually hear inside as if the announcer was whispering into your ear. Why should they? Audio is magic. Still, keeping the illusion going without pulling back the curtain takes a lot of work.

I read a recent article, where Bob McCarthy (a large scale sound system pioneer), cleverly pointed out that you always hear the huge explosion in a movie at the same time that you see it, even if it’s a mile away. When the Death Star explodes in StarWars, the camera shot might be from the distance to the moon… but you still hear the boom at the same time that you see the pow. I never noticed before. Now I’ll never be able to ignore it. Thanks Bob. Like my wife isn’t already annoyed enough that I can’t sit still in a single Theme Park Ride or Performance Auditorium without looking up to see what’s lurking above the ceiling.

By the way, another interesting point is that once you NOTICE something like lip sync error, your brain is much more likely to notice it in the future. In essence, you can’t un-notice it. Just like the way people don’t notice sound masking systems until they break. Our brain is trained to look for certain patterns that it expects. Our perceptions are not so much accurate interpretations of reality as they are a shorthand transcription, based on our previous conditioning and expectations of reality. Once that cat’s out of the bag, it’s not As an audio consultant, These days, we have such flexible tools at our disposal to perform “miracles” that just two decades ago would have been considered impossible. going back in.

I’ve talked a lot about audio consulting. Don’t get me wrong. I love designing creative video and projection solutions for clients too. In those cases, though, I’m more confident they’re going to have an appreciation of what’s been achieved at the end of the project. The whole point is to be eye catching. By contrast, I’m doing a good job on the audio system when they don’t notice that it’s turned on.

Years ago, I engineered a concert hall and when the opening night came, there were two international artists and a well know Symphony as the entertainment. The balcony creates a “shadow” that blocks the sound from the main speaker system, so we use speakers mounted in the ceiling above these seats to augment the sound from the stage. Then we delay those speakers to allow time for the sound from the main stage speakers to reach that location. Ideally, they both arrive at the same time avoiding an “echo” between the two systems and other problems. All pretty routine stuff.

The touring engineer for the headliner told me that the under balcony delays were off. I assured him they were not off and muted that zone of speakers. Suddenly, everything sounded dull. I pressed the button again and… voila! Everything came back into clarity as if we were hearing the main sound system. Despite the experiment, he still asked for a new system preset with the volume of the under balcony speakers raised, so that people wouldn’t “complain that those speakers were off”.

That reminded me that it’s important not to lose the love of what you do for a living. When I got that jaded with live sound, I left and went into design engineering. Sometimes things just happen for a reason.

What’s really amazing is that all of these thoughts ran through my head within about 60 seconds of watching those fireworks. Then I was pulled back to reality by my 4 year old daughter (who is afraid of fireworks) holding her ears (my little audio engineer) and asking me to make them stop. Now what do I do? I’m a good with audio, but I still can’t work that kind of magic. Fortunately, there is magic all around us. This time I found it in the form of a snow cone that quickly resolved the problem. Too bad that doesn’t work in my world anymore… or maybe it does. You’ll know what’s going on if I show up to your next design charrette with snow cones.


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