TECH TIPS


Multi-Channel Surfing
Tips for Modern Sound Effects Recording
story and photographs by Rob Nokes, MPSE


Rob Nokes conducts listening test of gunfire during shooting of James Mangold's 3:10 to Yuma.

With the advent of so many digital audio recorders today, it makes sense that the art of sound effects recording is advancing along with the accessibility to inexpensive, high-quality hard disk and flash recorders. The list to choose from is seemingly endless (Zaxcom, Sound Devices, Fostex, Aaton, Edirol, Sony, M-Audio, Marantz, Tascam, Zoom, etc.), thus making it possible to work with multiple recorders at one time.

I had shot with a pair of two-channel Fostex FR-2 digital flash recorders for a couple of years, and wasted a lot of time syncing the recordings. So when the time came to purchase a new recorder, I looked at four-channel models and realized that I would need to purchase multiple recorders to record cars or other vehicles––and still be faced with synching my recordings. Hence, I stepped up and purchased a ten-channel Zaxcom Deva V.

While a Deva V is probably far beyond the needs of most sound editors, the recording shoots that I am often faced with include labor, rental, props, location and donation costs that run into the thousands of dollars. If, for example, I am renting an airstrip for $1,000 and two planes for $5,000, it makes sense economically to record each plane correctly the first time so that it does not have to be re-recorded again. With eight microphones onboard, you are certain to get several excellent channels, along with an opportunity to explore microphone selection, technique and placement––while still ensuring that the sound editors are delivering recordings.


Set up shows a Deva 5 Hard Disk Recorder in bag and three Neumann 190/191 Stereo microphones shooting at 100 degrees X/Y.

For example, on board a plane (in this case a T-6 Texan and a 1941 Stearman biplane for the 2005 Korean film, Blue Swallow), you want to place your main microphones in locations that do not have wind hitting the microphone. However, that can occur in a location that is far from the engine. As an experiment, try placing a microphone outside, next to the engine, yet behind some steel so that no wind hits the microphone directly. With traditional recorders, it would be too expensive to experiment like this.

Yet, with a multi-channel recorder, you can try several permutations and find that sweet sounding spot.

Another benefit of multi-channel recording is the elongation of time. For Doppler sounds that move quickly past a microphone, I suggest using an array and capturing the sound at multiple positions over time. Array mics do not need to be expensive; they simply need to capture a sound for the brief moment that it passes that point in the array. Whether it’s water bubbles rising to the surface or horses, cars, swimmers, etc., if it is a Doppler-like sound, it can be captured from multiple locations and mixed together to form a sound many times longer than if it was recorded with just one microphone. For external POVs, I use three Neumann 190i mics; for underwater, I use two DPA-8011s and five custom-made scientific hydrophones, which are a tenth the cost of the DPA-8011, and sound better to me.


Mounted under the hood of a Prius for the 2007 release of Michael Lehmann's Because I Said So are two Sennheiser E835s dynamic microphones and one fingernail-sized Countryman Lavalier mic.

For ice-skating and horse hoofs, recorded for Miracle (2004) and Seabiscuit (2003) respectively, significant speed is involved, and that results in wind noise on the microphone if you shoot a close onboard perspective. The best sounding perspective is an external one that lasts about four seconds. As the ice skater or horse passes by, the sound actually lasts longer but it gets lost in arena reverb or background noise. By using a mic array, it is possible to capture those four seconds repeatedly to create a constant recording of the best perspective for the skater or horse.

With eight microphones, it is possible to capture multiple external points in time so that a Doppler sound effect can be captured and combined to create a much longer external sound.

Underwater sounds are another great example of how multi-channel recording can be made bigger and better through additive synthesis, the basic layering of recordings. A single channel recording of a bubble going from the bottom of a pool to the top passes by quickly and is at one very short moment loud as it passes by the hydrophone. Using a vertical array, the bubble passes six hydrophones that are layered together to create a loud recording of bubbles rising to the surface, and then the last two channels can capture the sound of the bubble popping on the surface.

With guns, it is possible to record a close perspective, a medium perspective, a bullet-by perspective, and a distant perspective. On 3:10 to Yuma (James Mangold’s upcoming remake of the 1957 Western), we used two close microphones next to the barrel of the gun or rifle, and a 360-degree array with a stereo channel facing the shooter (100 feet away), and two stereo channels facing into the mountains from which the report and decay would emanate.

After having mastered the gun recordings from 3:10 to Yuma, I would record the same series again with two close microphones (boundary and dynamic), a medium-close stereo microphone (100 feet away), and two very distant microphones several hundred feet apart and some 400 feet from the shooter.


Dodge Viper showing "fishing pole" Sennheiser E835s in both the draft position and strapped to the bumper.

On cars, it is critical to have external onboard microphones that are not impacted by wind as the car moves. In order to achieve this, I like to back a car up onto blocks and tuck microphones into the underbody out of the wind’s path and away from the constant whine that most car tires make. Low frequencies seem to build as they emanate away from the muffler, so I like to get very close to the muffler with a dynamic microphone, fairly close with a boundary microphone, and medium close with a dynamic microphone affixed to a shock-absorbing fishing pole.

As the low frequencies from the muffler expand and reflect off the car and paved road, the microphone on the fishing pole captures a different perspective than that off the close muffler recordings. It is important to note that the drafting position of the microphone on the fishing pole should be tested so that the microphone is not directly pounded by the wind. Depending on the car, I find that most cars draft about 24 to 48 inches away from the back bumper.


Recording set up mounted on the undercarriage of Toyota Prius for Michael Lehmann's Because I Said So, using Sennheiser E835s wrapped in a zeppelin cap and wind sock to reduce wind on mic.

Onboard interior car microphones are much easier to place. However, make sure they are securely attached to parts that do not become hot and ensure that the cables run safely through to the recorder inside the car. On muscle cars, the air intake perspective can often produce great sweetener sound effects that make chase scenes more exciting.

With all these microphones and recording technologies, it is important to stress the obvious: Find the best sound to record before you take the time to record it. A poor sounding object or environment is not going to sound good no matter how well you record it, whereas a great sounding object or environment will still sound good despite the recording technology or technique employed. Find a good sound and then record it as best as you can. That is the best advice I can offer.

Rob Nokes, MPSE, is Supervising Sound Editor for the TV series Bones as well as a Sound Designer/Recordist for major motion pictures. He is also the founder and owner of Sounddogs (www.sounddogs.com), a leading supplier of online sound effects and production music.

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