Broadcasting came of age in the analog era, but it has registered seismic expansion in the last several decades almost entirely from the migration to the digital domain. The lone exception to this digital migration has been transducers, specifically microphones and speakers. Microphones certainly are the last vestige of the analog broadcast world.
Microphones and speakers are the soul of the audio universe and the direct connection to our brains by way of our ears. Basically, microphones capture sound from moving air and convert that movement to electrical impressions.
This fundamental principle is accompanied by the fact that microphones capture the tonal characteristics of sounds, but tone (the sonic characteristics of a microphone) will vary with design, construction, materials and certainly with placement.
Stadium Sound Specs
Listen to college football: Each week, there are about a dozen college games across six different networks and they all sound different. Why? Let’s investigate.
Most field sound is captured with parabolic microphones, which capture sound with about the same frequency content. However, the frequencies and the tone of the crowd make up the biggest difference. Naturally, indoor stadiums like those the pros use and outdoor stadiums will sound completely different, but why do the crowds at outdoor stadiums sound different from one broadcaster to another?
In large spaces, microphones tend to be omnidirectional, so placing the mics at different distances from the crowd is the essence of sound design and sculpting. By combining the different microphone sounds and textures, you are sculpting a soundscape to give a balance of close, middle and distant perspectives.
Microphone placement is the secret sauce of sound design. Where these microphones are placed depends on the sound designer or mixer’s taste, experience and the cable and mounting for the installation.
Sculpting the Soundcape
In my early days of NASCAR, we would climb to the top of the scoring tower and place microphones more than 100 feet above the ground. Although it was a very scary climb, the sound was perfect for that long, back-stretch camera shot. Another example of how distance sculpts the sound is at an outdoor football venue where it is common to put shotgun microphones on top of the roof, pointed across the field.
The distance from the microphone to the sound source impacts the frequency and intensity of the capture, and improper microphone placement can destroy the desired sound-capture characteristics. An unacceptable and common practice in sports is to place a shotgun microphone flat on a camera lens (Fig. 1). Not only does this placement change the mic’s capture/rejection pattern, but also its frequency and sensitivity.
Probably the most hideous-sounding audio is from the on-camera podcaster. When you choose to use your computer’s built-in microphone, you will get bad-sounding audio, and if I were the producer, I would reject audio that sounds like you’re in a trash can. I don’t just blame the producer for accepting bad audio, but the technical department for not putting out specifications and equipment recommendations—it’s an easy fix for a few hundred dollars.
Home Studio Hacks
In addition to using a good microphone fed directly into the computer, some basic application of acoustics will also help your sound. Everybody does the shot in front of books. Move those books to different depths to help diffuse the sound.
Or, you could use fabric over the walls to absorb sound. Any trick will improve the sound and not detract from the visuals. Also, the on-camera subject should wear earbuds or headphones, so as not to inject sound from the computer.
Drama, sitcoms and variety programs are recorded on soundstages where unwanted audio is controlled. Generally, the acoustics are good, and with movies, dialogue is rerecorded and soundtracks are created. Broadcasting inherited the microphones and techniques from the film and movie production industry—an industry that once upon a time would “fix it in post.”
No doubt gaming significantly impacted broadcast sound, and particularly sports sound, with John Madden’s “Madden NFL” video game series. It was Madden himself who fought for high-quality sound and convinced the NFL players’ union and owners to change their minds about microphones.
Big events like the World Series are spectaculars, where sound designer Joe Carpenter rolls out the highest level of sound capture possible with microphones in the bases, along the outfield, on the boundary poles and even arranged at various spaces around the stadium to capture the spirit and perspective of the sport.
Big events showcase big sound, but big sound is possible for all events if there is a willingness to cooperate towards a suitable solution. Even though an athlete may object to wearing a microphone, it is the fans and the owners who pay their salaries.
The physical limitations of microphones should not be amplified by mistakes and misunderstandings. Audio production for broadcast is subjective and sometimes tricky, but should always be entertaining and bigger than life.
