Audio Monitoring: Still Subjective in a World That’s Both Digital and Diverse
By Dan Daley
Audio monitoring remains a subjective proposition in an increasingly objective universe. In the pursuit of commonly agreed-to standards for digital technology in general and 5.1 audio in particular, speakers are a speed bump, a category whose products often refuse to be categorized. As a result, a signal passes through a diverse array of transducers from mix truck to host broadcaster to various distribution channels before it ultimately comes out of the home set.
“Everyone monitors their own little world. There needs to be an overall audio producer, someone who monitors the sound from the mix right through the chain of distribution,” says Blue Sky VP Chris Fichera, indulging in some wishful thinking.
But his larger point is that, given the relative diversity of the monitors that mixers can use, their nuances are overshadowed by what he says is a lack of attention to the acoustical environments of broadcast-sports mixing, particularly truck units. (The mixers themselves will weigh on in this topic later this month.) “We need to see more emphasis placed on acoustical treatment inside the trucks and on speaker placement, especially for 5.1,” Fichera says.
Peter Chaikin, director of marketing for recording and broadcast at JBL, agrees. “There are two elements to what [the mixer] hears,” he says. “The speaker determines most of what you hear, but the environment in which you listen determines a significant amount of what you hear. At the mix position, you hear a blend of direct and reflected sound. A well-designed speaker ensures that the reflected sound component is neutral. Low-frequency problems in particular are common in the small production environment and can mislead the mixer. To overcome these problems, room measurement and system calibration are required.”
Several monitor systems aim at compensating for low-frequency problems, providing active calibration systems coupled with self-powered speakers. These include JBL’s Room Mode Correction (RMC) technology, which measures and automatically compensates for the effect of low-frequency room modes at the mix position, and Genelec’s Loudspeaker Manager (GLM) control network and its AutoCal automated calibration component.
Another often fuzzy area is bass management, a function that is sometimes productized but which basically boils down to determining the crossover frequency. In typical production spaces, that generally starts around 80 Hz but, in truck environments, could cross over anywhere from 80 to 100 Hz. In addition to reproducing the surround-sound low-frequency–effects channel (LFE), a sub can be used to reproduce the low-frequency information from all the other channels.
“Since each speaker’s low-frequency performance is very room- and placement-dependent,” Chaikin explains, “the practice of bass management can improve low-frequency accuracy at the mixer’s seat.”
But he also concedes that attaining accuracy at the mix position can be difficult not only because of the acoustical issues common to trucks but also because increasing the number of sound sources in a 5.1 system makes consistency much more challenging. Put the monitoring system into the confines of a remote truck, and you wonder why they don’t pay mixers more. “The reality is, speakers are all over the place and often so is the sound,” he sighs.
Then there’s the reality that, 5.1 or not, television remains a video-centric proposition. And we’re not just talking philosophically here: the inside of a truck is awash in flat-panel displays.
Will Eggeleston, marketing director at Genelec, was impressed with the audio provisions for Mansion Mobile’s new 53-ft. Expando HD truck that he saw at NAB last month. It is the first mobile unit to use Genelec’s DSP calibration software and also sports an SSL C100 HD-S digital broadcast console. At first assuming that the truck would be used for entertainment broadcasts, he was pleased to hear that it would be working MLB, NFL, NBA, and MSL events as well as Big 12 Conference college football games.
But that kind of audio in a truck remains an exception. Eggleston acknowledges that, instead of a video-centric conspiracy, it’s a simple ergonomics issue that remote audio is grappling with. “Fortunately,” he says, “the technology has been letting us make better speakers even smaller. Pound for pound, speakers in general deliver far more performance now than a decade ago.
And monitors may have to find ways to get smaller and smaller still, because as fuel costs start rising again, don’t look for trucks to get any bigger.