After months of listening to games of American football, I once again wonder why audio sounds differently across the networks—CBS, Fox, NBC and ESPN/ABC—for basically the same event. There seem to be several noteworthy variables that significantly shape the sound of a telecast including the venue, the broadcaster/network and finally a sound mixer’s tone, processing and mixing style.

Stadium Sound
When football first went on the air there were no indoor stadiums and they played in the rain, snow and occasionally in sunny conditions on grass. Audio coverage was mono and basic with various parabolic receptor designs, but the sound was adequate for the moment. My sound impression memory is that there is a sound to a snow-covered icy stadium with hard surfaces, a crispness that carries the sound. But broadcast sound changed with the addition of roofs, artificial surfaces and PA craziness. 

A little physics tells us that an “open stadium” lets the sound/noise escape from a confined space. Sound energy builds and the cumulative effect is destructive to a clean capture for television purposes. 

Jonathan Freed, mixer for ESPN/ABC, stated the obvious: “Open air stadiums sound different because the PA and crowd don’t echo off the roof and walls when there aren’t any.” 

Additionally, Freed has presented his theories about “air inversions” for years. “In a really cold outdoor stadium the warm crowd and heaters by the team benches cause a layer of warmer air to rise and when it gets to a certain height it collides with the colder air forming an atmospheric inversion layer over the stadium. Sound from the field of play will actually reflect off of this layer back towards the sidelines and in some cases create a noticeably fuller sound for the parabs to pick up.”

The venue acoustics clearly are a factor, but Fred Aldous of Fox Sports told me that “the PA systems have gotten bigger and louder, and, significantly, the PA usage has crept into play action," Aldous said, “Music is being played over kickoffs and at the end of play, which interferes with useable field of play sound.” To make things worse, several years ago Atlanta was fined for pumping crowd sound back through the PA.

Acoustics impact the tone of the sound that the microphones capture, but the mixers control the balance of the sound elements—announcer, effects, crowd and music. With most major sporting events there is a significant effort to capture the sound from the field of play. Microphones and their placement are not a secret and there is fair consistency across the different mixers and networks particularly today, but clearly this did not happen by accident. 

My sound observation is that Fox Sports mixes in more field presence. David Hill was chairman of Fox Sports for almost two decades and was instrumental in advancing the sound of football with his persuasion of the NFL to allow wireless microphones, first, on officials, and later, on players

Sound Variables
Even though football has had a powerful advocate with Hill, the NFL still controls where and when microphones can be placed and opened. 

For example the NFL does not permit microphones near the benches and regulates the use of the microphone on the sky cam and even controls opening the player microphones before the networks receive a feed. The sound obstacles and variables
are well entrenched in the Sunday sound and there are guidelines, but there are differences in NFL crews. I have been told that some NFL sound personnel are better than others.

Of the number of games telecast on a Sunday afternoon, it seems that there would be a desire for a network to have consistency between the multiple games that are broadcast. Phil Adler,  who did audio mixing for CBS Sports for more than two decades, told me that the network only has a mandate that the announcers’ volume level be between 4 and 6 dB louder than the field sound, but everything else is subjective to the mixer.

Aldous believes that Fox’s consistency endures because of weekly phone meetings, adding that while the meetings are not mandated, they do offer a forum to share ideas, philosophies and give “ownership” to the mixers.

Given that the sound variables, which include microphones, venue characteristics and technical facilities are somewhat equal, then the real difference is that the sound is the artistic and subjective interpretation of a sound mixer. You can not underestimate the range of subjective interpretation of a single sport from a group of audio practitioners that bring the consumer 16 consecutive Sundays of NFL football. 

Experience Counts
As with everything in life, experience is the difference. It is hard to understand how unpredictable live sports can be, and how much of a challenge it is for the mixer to control, manage and tame the sound. 

An inexperienced mixer tends to use too much compression to control the wide swings in the sound. Under compression/limiting can lead to the sound distorting through the signal chain while over-compression can be equally unpleasant with the audio pumping up and down.

An inexperienced mixer may not understand why the transmission signal flow was problematic when the networks went from mono to stereo and then to surround. What about immersive? Even though there is little talk of football in immersive sound, it is going to happen, and the learning curve will impact the sound of the show. 

Finally, sound reproduction to the consumer is a moving target as well. Stereo, surround, immersive, soundbars, headphones, TV speakers—my head hurts. Sound has been equal parts evolution and innovation and maybe a little sound voodoo. What draws viewers’ attention to a game, even if they are half asleep? The sound! What can carry an entire show without pictures? The sound! 

The audience can finally hear a difference and sound is a differentiating factor with broadcast brands. Some of my interviewees commented that some of the broadcast sound today is difficult to listen to. 

NEW YORK—While there continues to be some debate about the health of the NFL’s television ratings in the post-Colin Kaepernick era, it is generally agreed that both the video and audio elements are continuing to evolve. That is particularly true when it comes to mixing audio for the gridiron.

Fred Aldous and Gary Trenda work on opposite ends of the audio thread. Aldous serves as senior mixer and audio consultant for Fox, for whom he mixes the “A” NFL game of the week. He has snagged a mere 23 Emmy awards and is a member of the Sports Broadcasting Hall of Fame. Educating the next generation of audio specialists is critical to Aldous, who helped build the audio curriculum taught at CRAS, an audio recording school in Arizona.

Trenda is an audio and RF technician who provides technical services to a variety of industries. He works on a wide range of wireless audio system projects, including the Latin Grammy Awards and Super Bowl Halftime Show. Trenda is also a member of the audio staff at Lam-beau Field where he supervises a team of specialists who provide audio for the Green Bay Packers games.

IMMERSIVE, THE NEXT STEP?

The audio portion of the Green Bay Packers game day presentation breaks down into several components, according to Trenda. “One engineer has the job of mixing sound for the main bowl of the stadium, another mixes for the rest of the facility,” he said. “The difference between the two is pretty easy to understand. If a fan leaves their seat to go into the concourse to get a hot dog, we provide audio that includes the local radio broadcast so they can stay in touch with the play by play action. We call that our ‘back of house’ mix. Obviously, play by play audio is not required for fans who are inside the bowl watching the action.”

Where does Aldous think we are in the evolution of sports broadcasting to the home market? “The next step will involve more immersive audio, specifically Atmos [adding height to the viewer experience].” he said. “This will give the viewer a better ‘in stadium’ experience.’

Aldous has mastered 5.1 over the years, which brought a whole new dimension of the in stadium experience from stereo and Aldous expects the move to Atmos will do the same.

“In my opinion specialty events will incorporate this before regular sports season events,” he said. “Over the years we have relied on Sennheiser products to help us do the job that requires a high level of confidence. They are very good at creating innovative products that satisfy the needs of our industry.”

Are audio mixers waiting for video technology to get to the point where the viewer can choose from a number of visual perspectives (the 50 yard line on a football field, say) to develop techniques that will match sound to picture in a number of different streams simultaneously? “With VR on the horizon I believe that we will be able to send more specific audio along with picture,” says Aldous. “It doesn’t make any sense to do so now, as the perspective of the field of play remains in front of the viewer at all times-for now!”

GAME COORDINATION

Trenda’s team coordinates with the broadcast crews that the networks send in. Each home game is different. The crews who handle audio for NBC’s Sunday Night Football or Monday Night for ESPN tend to remain the same year after year. The personnel who cover the other games can change based on which TV truck is sent.

“We send these crews our stadium audio elements—the referee microphone, for example. Depending on their needs, we can also send them the material that goes into the bowl-player introductions, the stadium announcer giving down and distance, that sort of thing. Each crew decides what they want to use from the stadium elements.”

If LeBron James is dribbling up court, or a half back breaks through the line and sprints 40 yards to the goal line, will mixers demand that microphone and console manufacturers provide gear that will allow him/her to match picture exactly? That day is upon us, says Aldous. “We already have that technology. What restricts us now is access to players with mics that we can broadcast in real time. We are very mindful of language and the possibility of something going indiscreet being sent over the air. We do record a lot of mics, and edit content for playback once it is sanitized.”

Will we get to the point where automation syncs audio to the moving image in real time? “Unfortunately I think we will get there at some point—what will be lost is the finesse of the mix. Automation cannot recreate the detail that a human can provide. We add a lot of different elements to a mix that are not camera specific to make the mix realistic.”

An intercom connection ties together Gary Trenda’s team and the broadcast truck. If, for example, a television producer wants to broadcast the player introductions, the TV crew can take audio from the Packers’ feed and can cue the start of the introductions via the intercom.

Audio delay is also something that needs to be accounted for. “There can be a significant delay between the live action on the field and a TV or radio broadcast,” Trenda said. “Rather than taking the broadcast audio feed from a radio or TV tuner, we’re able to get feeds directly from the TV truck and home radio booth. These direct feeds allow us to sync the audio with the action on the field.”

RF CONCERNS

Repercussions from the FCC sale of chunks of the radio frequency spectrum continue to impact sports broadcasts.

“The most recent FCC TV Band auction included the sale of much of the 600 MHz range, and we’re in the midst of another TV station repack," said Trenda. “Any TV stations currently broadcasting on channels 38-52 will be repacked to a lower channel number, which will increase crowding in TV channels 2-36 and make it more difficult to find space for reliable operation of wireless systems. This includes important game elements like the referee mic. As the RF spectrum gets more crowded, people will consider using wired microphones where they can.

“We currently use Shure Axient analog wireless microphones for the referee. One way manufacturers are responding to the loss of RF spectrum is with microphone systems that can be more spectrally efficient. Shure Axient Digital, for example, has a high-density mode that allows the user to fit more transmitters into less space. When the time comes to replace our current system, we’ll definitely consider new technology like this to address the challenges of a crowded RF environment.”

The reduction in frequency range has left production crews to make some tough choices. It can be difficult to know what area of the RF spectrum will be available in different cities. Some equipment will continue to be legal to operate, but others will need to be replaced entirely.

“In some cases, there’s no good upgrade path,” Trenda said. "We have a few systems that will simply need to be replaced to comply with the new FCC rules. It’s important to understand the changing RF environment and have a comprehensive band plan for your entire suite of wireless equipment.”

Top photo: Master control at Lambeau Field, home of the NFL’s Green Bay Packers