"Sound Speed"- 5 Audio Mistakes To Avoid On Set
Audio and film go hand in hand and having high quality audio in your productions is a must, whether you’ve considered that or not. Most will tell you, less than stellar visuals but great audio will keep fans engaged but poor audio quality will pull anyone out of the scene. In my travels, I’ve found a few pain points on set that people will overlook or outright bypass, resulting in poor audio quality that could easily be avoided. Below are a few tips you can use to help make your productions stand out and give a higher likelihood of success.
Mistake #1: Improper Boom Technique
When it comes to working on set, the go to mic choice for any production will be a boom mic. These mics, also known as Shotgun Mics, are designed with an extremely tight polar pattern which helps to reduce extraneous noise and focus how the mic picks up the audio. These mics are perfect to capture clear and quality sound if approached with a few simple ideas in mind. Often the biggest mistake is proximity to the talent, which at times can't be avoided when not having a dedicated sound mixer on set. Being too far away adds too much room tone/ambiance and may make the audio sound out of place in context of the scene, however, you can use this to your advantage at times to add realism to the scene. If you don’t have a dedicated sound mixer on set, you can try to put a stationary mic stand over the talent to try to capture the audio in closer proximity, mimicking the role of a sound mixer on stage. It might be a bit tedious to set the stand sup and move around in the context of different shots and blocking, but the audio quality will be much better overall. Another common issue is where your pointing the mic, such as towards the sky or scaling. Doing so will add far more extraneous noise by picking up everything behind your talent. Pointing to the floor or ground helps to better acoustically isolate your talent and keep reflections off walls down, background noise to a minimum and help top keep down the sounds of airplanes, cars or traffic. Certainly, these items may show through in the audio, but we can minimize the effect by ore diligent placements and technique.
If you don’t have access to a Shotgun Mic, a good quality dynamic microphone, such as a Shure SM57, can be substituted but the polar patters are much wider and will pick up more extraneous noise
Remember that most Shotgun Mics are Condenser Mics and require Phantom Power to operate
When recording ADR, it’s a great idea to use the same mic that was used on set to keep with audio consistency
Mistake #2: Improper Lav placement
Lav microphones (Lavaliere or Lapel Mics) are excellent to combine on set with a Shotgun Mic. The Lav mics are close proximity and help to create the sense of intimacy, clarity and allow you have a blend between more room tone and close proximity. Lav mics can be hidden with ease and provide high quality audio while on set. However, several issues do arise when working with them on set, most noticeable is clothing rustling noise. When materials rubs against the Lav element, it will pick up and make rustling, crunching or other unpleasant noise. A super easy way to combat this issue is to use The Sandwich Technique:
Install the Vampire Clip to the Lav in order to pin the mic to the talents clothing
You’ll need two pieces of gaff tape and fold them into two triangles, sticky side out
Sandwich the Lav cable between the two pieces of tape. Pay attention to not cover up the Lav element
Using the Vampire Clip, clip the lav element to the talents clothing and stick the tape sandwich to the inside and outside clothing to hold the Lav in place
Add two loops of slack to the talents side and secure above and below with tape. In case the talent makes any reaching or sudden movements, it’ll apply the slack instead of tearing off the Lav
This technique yields great results by helping to reduce material noise and rubbing by effectively isolating and decoupling the Lav element and acting as almost a makeshift shock mount. If the client isn’t wearing any under shirts to pin two, you can pin to the outside layer and stick the tape to the skin. Just let them be aware when they remove it.
Mistake #3: Not Capturing Room Tone
An often-overlooked component to working on set, I always recommend capturing at least a minute of ambient room tone for each you shoot. This comes in handy during editing when there may be some continuity issues with audio in context of the edits. Having room tone on hand can help the mixers inset those tones back into smooth those edits out as well as help to capture the organic feel of the scenes. If the audio quality is good and the room tone is appropriate, nothing’s better than using the real thing. I always recommend keeping those tone son hand to build a library of room tones you can call up for a verity of uses. Personally, I’ve recorded room tones for my entire house and use them on projects often.
Ideally, you’ll want to capture the tones with no one present and complete quiet on set. Situations where you have complex ambiance, like outdoors or near busy streets, are tricky in regards to continuity of editing tones so capturing as much as you can with as much quality will help create that sense of realism. Outdoor shoots have their own set of challenges, wind, engines/motors and other issues can creep in but at times, can be useful to create more realism. If its at all possible, a second sound person on set or stationary mic to capture ambiance as lines are being delivered can help if there are instances of traffic passing left to right and keeping with the realism of the scene.
Mistake #4: Gain Staging for Video
Another common issue is improper gain staging for the audio. In essence, gain staging is understanding in your signal flow, how many points there are to adjust gain going into the camera or recorder. The goal is to record with good enough level to capture the best quality audio and reduce the equipment self-noise and increase signal to noise ratio. Self-noise is the inherent amount of noise the collective equipment will add to the signal due to the components used to build the gear. Higher end mics and recorders tend to add less, but a good rule of thumb is to ensure you’re recording song levels but not clipping the signal. It seems obvious, but in the rush of getting a scene shot these can go by the wayside. Signal to noise ratio is simply how much level for your input signal vs the noise in the signal. If you record too quiet and we try to boost up the audio after, not only will we increase the audio level, but any noise and junk recorded with it comes up too. It’s much better to need the mixer to turn the audio down and maintain quality than it is to try to fix it after. Fixing it in post shouldn’t be in your vocabulary, capture it right the first time.
Mistake #5: Diminishing The Value of Sound
A final point is the often-diminishing value of audio in the project. Sure, picture is king when it comes to film but I assure you, the most visually pleasing project with garbage audio will get you nowhere. Spend a little more for a quality audio person and post work to give your projects the quality they deserve. Sit with your audio crew, both on set and post, and create a plan of attack to ensure everyone’s in the loop on the scenes and how the layouts/blocking look. Give them opportunities to tour the sets in order to point out potential problems that can be addressed before getting on site. The more prepared we can be for your audio needs, the better and faster we can capture the audio with more quality. A little extra patience and investment to your audio will yield enormous dividends on on ensuring were achieving your vision or your project. Giving cleanly defined direction on your audio goals and needs will help all of us reach your visions faster. Be open minded to suggestions on how we can make the audio that much better but realize we understand this project is yours, we just want to make it as great as we can.
I hope with a bit more insight here, you can get a better picture of the audio process on set and in post. I hope this will guide your habits in the future to aid in better quality work which will in turn, save you time and money on the post process. Invest in your audio as much as your visuals and I guarantee your project will be even better than you can imagine. The goal is simple, help you to create and achieve your artistic visions and goals with our skills. In the end, were all striving to create partnerships and relationships and our skills are how we reach those levels. Share your thoughts on your experiences, tips and techniques below!