In Part 1 of this series, we discussed the importance of isolation, or emphasizing the desired audio as compared to the ambient noises.
We also discussed how the directionality of a microphone, as defined by its polar pattern, affects the audio that is emphasized. In this 2nd article we will focus on how to capture better on-field audio.
There are three keys to capturing better on-field audio.
- Using more microphones
- Locating microphones closer to the action
- Using more directional microphones for better isolation
While these three keys may seem rather obvious the application may not be. Let’s begin by examining how the networks typically capture audio at a baseball park.
Baseball – Typical Network Setup
For a typical, high profile baseball game the networks will utilize the following:
- 2 or 3 parabolic microphones on stationary mounts behind home plate to capture the crack of the bat, the pitch hitting the catcher’s mitt, and the umpire calls if their wireless mic should fail,
- 2 microphones on the dugout cameras, usually shotgun microphones,
- 3 parabolic microphones, manned by operators, in the outfield stands,
- several shotgun microphones in the bullpens,
- shotgun microphones along the dugout walls, and
- wireless lavaliere microphones embedded into the three bases.
I attended an MLB All-Star game where both a 100-channel primary mixer and 48-channel sub-mixer were using every single channel.
The diagram below provides a graphical representation of how the pickup pattern of the primary microphones cover the field.
For games with regional coverage, the setup may be as simple as 2 shotgun mics behind home plate, and a shotgun mic on each of the dugout cameras.
You will notice that a parabolic microphone was used in this scenario. A parabolic microphone is different than any of the other microphones we discussed in part 1 of this series.
A “parabolic mic” is an electronic microphone element (sensor) inside a parabolic collector. A parabolic collector reflects all the sound energy coming from the front of the dish onto a single point, where the microphone element is located. The “collection of the sound energy from a large area onto a single point provides a significant amplification. The amount of amplification is determined by the dish diameter.
A 26-inch diameter parabolic mic can capture a conversation from 500 to 600 feet in quiet conditions while a 9-inch diameter parabolic mic can capture a conversation from 30 to 50 feet in quiet conditions.
The adjacent diagram illustrates how the special shape of the parabolic collector focuses the sound energy onto the focus point.
While parabolic mics are used frequently behind home plate for baseball games, they may not be visible as they can be located behind a mesh fabric imprinted with a logo or used as green screen for advertising. When used on a temporary basis, such as a playoff game, the parabolic mics are also often mounted inside enclosures to protect the players, and the parabolics.
Baseball – Very Low Budget Setup
When the budget is very low, a single camera-mounted shotgun mic can be used to cover both home plate and first base. The diagram below shows the pickup pattern of a typical shotgun microphone pointed toward each base. Notice how the cardioid pickup pattern extends outside of the playing field. This will allow crowd noise to be captured at a level equal to the play on the field.
Using a small parabolic microphone instead of a shotgun on the camera reduces the level of crowd noise that is captured. The diagram below shows the conical pickup pattern of a typical parabolic microphone pointed toward each base. Notice how the pickup pattern does not extend beyond the playing field.
Tom White created a video comparing a high-quality shotgun mic and parabolic mic in this situation.
Baseball – Low Budget Setup
Two camera-mounted microphones provide better coverage of the batter as well as both 1st & 3rd base. Either a shotgun or parabolic mic can be used in this setup. The diagrams below show the pickup pattern in this setup.
Baseball – Just Slightly Higher Budget Setup
A mid-size parabolic mic can be added to capture the batter as well as the infield. The two original microphones, shotgun mics or small parabolic mics, can be used on a camera or hard mounted in the dugout area near 1st & 3rd base. The diagram (right) should illustrate this setup.
Baseball – Medium Budget Setup
If funds allow, three mid-size parabolic mics can be used to provide greater coverage of the infield. When required for important games, additional parabolic mics can be rented for the outfield.
In Part 3, I will share typical setups for other sports.
Paul Terpstra has more than 35 years of engineering and product development experience. He founded Innalytical Solutiong, Inc. in 2004, to provide a wide range of engineering services including forensic engineering, Finite Element Analysis, electomechanical design, machine design, and machinery repair. Paul was recently granted his eleventh U. S. Patenr.
In April of 2012, Paul and Patrick Santini, an Innalytical Solutions customer, created Klover Product, Inc. Previously in 2011, thay had jointly dveloped a paabolic microphone for Fox Sports when Fox audio engineers grew disatisfied with the available products. That original test unit turned out to be the first prototype of the microphone that would latr become the Klover MiK 26. The Klover MiK 26 parabolic microphones have been used exclusiely by Fox Sports for football broadcasts since 2012.