Tech Focus: Audio Monitoring, Part 1 — In the Truck, It’s Still the Biggest Sound Challenge
By: Dan Daley, Audio Editor, Sports Video Group
Recording- and broadcast-studio designer Russ Berger sums up the challenges of monitoring audio in confined spaces — such as those in remote-production trucks — eloquently and concisely: “It’s like a complex little jewel box. All the problems of physics are compressed into one tiny space.” Like an episode of The Big Bang Theory but without the comic relief.
Music-studio designers who have worked on entertainment trucks enjoy a bit more space to work with for sound than their counterparts in the sports realm, but they say there are translatable principles that can accommodate both worlds.
“You’ve got to start with the right monitor,” advises John Storyk, who built Jimi Hendrix’s Electric Lady Studios, among hundreds of others, and who has done sound for more than a dozen sports venues, including at the World Cup, and a few broadcast vehicles. He suggests that the fairly limited array that seems to comprise the main choices in the industry can be widened without sacrificing weight or space.
Then there’s what not to choose. “Some monitors are meant to be used at high volumes, and those are not good candidates [for truck monitoring],” he says. “And you don’t need speakers with wide dispersion characteristics in that kind of environment.”
Storyk advocates self-calibrating systems for speakers. Such systems would better adapt different monitors for tight spaces by acoustically registering the dimensions and adjusting parameters, such as EQ, to fit it and would also allow for a wider range of speaker choice.
“Then you have to choose a good surround processor, such as the Lab.gruppen or BSS,” he says. “You need technology to overcome the problems caused by monitoring in a very small space. As the space gets smaller, even first-order standing waves are audible; in an arena, you’d need to get to the sixth order before you heard them.”
Berger agrees that listening at lower levels is critical to accurate monitoring. However, that can be difficult in trucks because there’s so much ambient and extraneous noise that interferes with the monitoring environment. Mass, in the form of walls and partitions, is the answer, especially mass combined with air space between the partitions, but, on a truck, that translates into two of its biggest enemies: added weight and reduced space.
Lack of space is the biggest hindrance to audio monitoring’s single biggest challenge in contemporary sports sound: bass. Whether it’s music or effects, low frequencies are the sound du jour for entertainment. But low frequencies need space — cubic volume — to unravel, something audio compartments on trucks simply don’t have.
Berger has come up with a solution, one that he has used on several entertainment-truck designs and that is proprietary to a degree so he hints at it as much as he explains it. Based on what he calls “leaky” technology, it involves porting sound from the audio compartment into the truck’s equipment-storage bay once it’s emptied. If the bay is at least in part directly below the audio-mix compartment, the floor can be used as a kind of membrane that gives low frequencies more of the space they need to propagate.
It’s not a perfect solution. Berger acknowledges that any such membrane would naturally work in both directions, potentially letting more noise into the mix compartment. But, he admits, any solution will have to be a compromise: “Again, it’s physics.”
In a somewhat simpler suggestion, both Berger and Storyk recommend that A1s keep the median plane — the area at ear level — as free of reflective surfaces as possible. “If you can keep equipment and other things around you below 48 in. high,” says Storyk, “it’ll help to reduce the possibility of comb filtering and other artifacts.”
How sound interacts with small spaces will always be a challenge for monitoring, and many mixers simply compensate mentally for environmental shortcomings. “Sound is a science,” he says, “but it’s one with more than a few gray areas.”