[Written by Ric Viers for Designing Sound]
Recording sound effects on a stage is much like eating at a fine restaurant. You know the fancy kind with fresh baked bread and a different piece of silverware for each course. Recording sound effects in the field is more like hunting for food with a rock and then eating your kill in the middle of the woods raw with your bare hands. One method is obviously preferred. However, not everyone can afford fine dining.
For Christmas this year, we gave away a free copy of the Sound Effects Bible Hard Drive to the winner of a video contest we held. Michael Chobot’s video “Sound Hunter Promo” perfectly demonstrated what field recording is all about. In the sound effects world, sounds are not handed to you on a silver platter. Sometimes you have to get your hands dirty and go primal with your microphone. Let’s discuss some hunting techniques.
Hunters head out into the woods wearing camouflage to blend into their environment and not be seen by their prey. Recording is the opposite. When recording, you want to camouflage the background noise or acoustic environment so that it can not be seen (heard) by your microphone. In my experience, the single biggest challenge in field recording is isolating the sounds.
Here are a few examples and tips to help you bring home the bacon.
Turn the lights off!
Recently we were recording net swishes in a basketball court. The sound itself is fairly quiet, so we needed to make sure that room was quiet. The problem we encountered was the buzzing light ballasts overhead. So, we recorded in the dark – a little tricky when trying to make a basket, but very effective for isolating the sound. It’s a good idea to bring a work light and a flashlight to locations where you anticipate turning off the lights.
Turn everything else off!
Last month, my team and I headed out to “Marvin’s Marvelous Mechanical Museum” to record an insane amount of arcade games, including some rare antiques from the turn of the century. This place was a gold mine! They had ski ball, vending machines, change machines, candy machines, antique bells, phones, even an ATM machine. The problem was there were too many machines making noise all at once. So, we cut the power to the building and worked in the dark. But, we needed to run power to each machine we were recording. To do this, we kept one breaker on and used a hundred foot extension cord to supply power to the machines.
Turn off the heating / air conditioning!
Nothing will spoil your perfect take of an office phone ring than the low rumble of heating and cooling systems. Instead of recording in an office, it now sounds like you’re recording in a hallway aboard the Starship Enterprise. Some buildings have zoned systems which will allow you to turn off the heating and cooling systems for the area where you are recording. Other buildings work on a single system that might not allow you to do this. You can try closing the vents in your area as well as stuff blankets or other items in front of them to stop air flow. In a pinch, you can use low cuts on your recorder, but this will affect your recordings.
Sound blankets (a.k.a. furniture moving pads or “furni pads” for short) are wonderful tools for damping reverb in a room, reducing vibrations from a rattling object or to even catch the shells being ejected from a gun while recording. They’re pretty easy to get a hold of (www.markertek.com/Acoustic-Materials/Sound-Blankets/VAN-PAD-BLACK.xhtml) and can be very useful problem solvers. Mic stands with boom arms can make nifty stands to hold your sound blankets if you turn the boom arm perpendicular to the ground, forming a “T” shape. Spring clamps can also be helpful for mounting sound blankets in difficult places.
Use a shotgun mic!
Shotgun mics are my personal favorite mics to use in the field for isolating sound. Their polar pattern allows you to point the mic at a sound source and virtually focus only on that sound. When recording at a location with distant traffic, positioning the mic in the opposite direction of the traffic can greatly diminish the noise produced by the cars. Once you arrive at a location, turn on the mic, put on a pair of headphones and point the mic in every direction. Sound comes from 360 degrees, so don’t forget to point the mic up and down as well. This will help you determine what directions to avoid when recording.
Loose the shotgun mic!
Like all superheroes, shotgun mics have their weakness. Reverberant rooms can create weird and unpleasant artifacts when using a shotgun mic. If this is the case, swap the shotgun out for a cardioid mic. Your recordings will sound more natural. Use your ears to make this call. Sometimes, shotguns can work well indoors. With recording, there are no absolute rules, just guidelines.
Get up close and personal!
The inverse square law is your friend! This mathematical formula basically states that sound pressure level is reduced by half (-6bB) every time you double the distance of the source to the microphone. In practice, this means that your sound source will be louder if you place the microphone closer – common sense, right? The benefit of doing this is that you are increasing source level and therefore reducing the background level. The drawback is that if you get the source too close to the mic, you will get the proximity effect (an artificial increase of lower frequencies). This can be a good thing and a bad thing depending on your sound source. Paper movement miked too close can produce enough low frequencies to rattle your fillings loose in the edit suite. In these cases, you’ll need to roll off the low end to make the sound effect seem more natural.
Point the mic at the sound source!
Duh! But, it’s not always as obvious as you might think. When miking a drawer, don’t point the mic at the handle. Instead, point the mic at the source of friction, which is where the sound is actually coming from. If you can mic the drawer from underneath, as with some desks, you’ll achieve better recordings. With other drawers, such as dressers, you’ll need to mic near the side corner that exposes the track that the drawer is riding on. The same technique can be applied to door squeaks. The hinges of the door are what usually produces the squeak. With some doors, you might find that there is one hinge that is more vocal than the rest. So, point the mic at the noisiest hinge and not the door itself. This falls into my “listen with your ears, not with your eyes” mantra. When deciding mic placement, experimentation is key. Find the sound. Don’t assume where the sound is coming from.
As humans, we quickly adapt to the acoustics of the environment that we’re in. It only takes a minute of being in a noisy environment before our brains begin to tune out the background and focus on certain things. This is why bars and restaurants get away with playing obnoxious music on Friday nights. People go to these establishments to socialize – to communicate with each other. This is possible because after a few minutes, the music becomes less intrusive on their conversation. Of course, they’ll wake up the next morning with hoarse voices from shouting all night. It’s easy to get lulled by the background noise or acoustics of the location where you’re recording. It’s important to take a moment at the beginning of the session to really analyze your location with headphones. What do you hear? What can you change? It can be a bummer to record for several hours only to come back to the studio and notice background problems in your tracks.
It all comes down to trial and error. With practice and lots of experimentation, you’ll start to get the hang of it. The secret to becoming a good field recordist is to keep recording. Record everything! Then listen to what you’ve recorded. What could you have done differently? Learn from your mistakes. Its one thing to read about recording to get the basics, but it’s another thing to put those basics into practice in the field. Who knows, you might even come up with some cool tricks to share with the rest of us!