We all know the tried and tested mantra of the best way to ruin good video is with bad sound. This article will help us cover the routine practices you’ll need to consistently capture good audio and to avoid problems before they appear.
A long time ago in a childhood not so quite far away, I remember watching outtakes from “The Mummy Returns,” with one particular scene featuring the antagonist flinging people across the set. Except, in this case an airplane very visibly and audibly flies through the top of the shot. The cast at this point loses it and starts laughing. That forever etched itself in my brain as an example of what you don’t want in a shoot, even if it was a chance occurrence.
From here on we will go over some simple steps to help you achieve a good level of accuracy in your audio that does not sacrifice quality, intelligibility or cause undue distractions.
What you want
By this point you should have in your possession a good set of pre-production materials and an idea of your location.
Decide how portable you need to be. Will you be part of a bigger crew with a production sound mixer, boom operator and assistant engineer? Or are you a one wo(man) band?
Test all your equipment and bring spares along, whether they are cables, wireless receivers, connectors, batteries, backup recorders or spare headphones. Try and get test levels both before and when you arrive on set. I will probably mention this several more times over in the next few sections.
Watch: Using a Field mixer to Get Better Audio
Good Signal and Levels
I assume that by now we are all recording digitally in the field and not lugging around tape machines. The cardinal rules, however, still apply: You want to get your average level to hover around -12 to -9 dBFS. You can go a little higher if the situation requires, but these are generally good recording levels because they provide a good noise floor and dynamic range. There is no coming back from an overcooked signal that has gone over 0 dBFS.
What You Don’t Want
This will include sounds and situations that you don’t want to or cannot fully resolve during post. The best policy, avoid them altogether.
- Equipment Woes
- Great take, bad cable is not your happy place! The same goes for the following:
- Dead batteries
- Wrong sample rates
- Bad microphone(s)
Test your equipment, regardless of quality. It never hurts to know that something works before you use it. Getting a level test is a good chance to give everything a dry-run.
Plosives, Sibilance and Clarity
Pop filters and windsocks are great tools for reducing both plosives and sibilance; the windsock helps to lessen the impact of the higher sibilance frequencies. If caught in a pinch, a pencil taped to the front of a microphone can server as an impromptu pop filter. Your choice of microphone can be just as effective with reducing sibilance, so pay attention to the frequency response charts and learn your toolset. Worst case, there are multiple de-esser plug-ins out there and included with major DAW’s.
Your choice of microphone can be just as effective with reducing sibilance, so pay attention to the frequency response charts and learn your toolset.
Add to this that you generally want crisp and unmuffled dialogue. Make sure that your target sound is always on-axis. Shotgun microphones have incredibly diminished off-axis pickup, other microphones will also color your sound if used off-axis.
Is moving or changing direction an option? Always try and minimize your exposure to the wind. You should hopefully be only having to deal with moderate wind, unless the director is trying to destroy the lead’s fancy hairdo.
Otherwise it’s all in the name: A windsock is your first stop when absolutely having to confront wind noise.
Use your inventory. Will a lavalier microphone be better shielded? If so, you should considering using it.
Background Noise and Generally Unwanted Sounds
The reason I have brought up windsocks so many times in the last three sections is because they are physical high-cut filters. The alternative is the low-cut filter option on most recorders and sound boards. These are are accepted starting points when trying to get rid of rumbles and hisses in the background.
Here is a list of sounds that you want to avoid:
- Car and traffic sounds
- Construction noise
- Clear and audible background conversations
- Interior noise or structural sounds
- Wind and rain
In certain cases you might want to run some specific equalization to target certain sounds. All's fair in love and war, as long you don’t negatively impact your target sound.
Equipment, Signal Flow, and Ambience
Assuming you already have an audio recorder — you can refer to our sound recorder buyer’s guide if not — the next step will be monitoring. Closed-back head headphones are the best starting point on account that they are low leakage isolating headphones. AKG produces a good entry with the K271 MKII that is equally at home in the studio and in live applications, while allowing you to still remain cognisant of the outside world.
There is also the lingering issue of noise cancelling headphones and whether they are suitable. My arguments against this approach is mainly one of price, connectivity and practicality. Most of these models are significantly more expensive, are moving towards wireless connectivity, are battery dependent, and most of all, impractical. Being able to survive regular daily use is one thing; the rigors of on and off set use requires something a little hardier. Wireless means Bluetooth and compression, you don’t want to be dealing with compressed signals during a recording and monitoring workflow.
Testing your recording for faults can be done in two steps. First make sure all of your equipment is working as it should in a controlled environment, for example at home or at the studio before you even get on set. Remember to bring backups!
Once on set, make some test recordings and find a quiet spot to play them back on your headphones. This will give you a baseline that you can compare against. This will help you avoid the mindgames associated with trying to pick apart ambient sound from your current recording.
Careful listening and following the above tips and precautions should give you more than acceptable audio to work with. Knowing what you want and what you don’t want — and knowing how to listen for it is the first step in recording better audio on set.
Sidebar: Monitoring Live Sound
Most live acts out there live and breathe by the quality of their monitor mixes. The Monitor Engineer reports to the Front of House Engineer (FOH) and is responsible for managing the stage monitor mixes. You can quickly find these mixes growing in scope from a simple blend of everything to bordering the complexity of a full on FOH mix, but instead your audience is a collection of in-ear monitors. It’s actually pretty fun!
A key difference is whether you will be dealing with monitor wedges and having to balance a separate yet very physically present stage mix or if you’ll be working with in-ear monitors. The big difference being one is audible and interacts with the environment while the other is beamed directly into to the recipient’s ears.
If you’re working with monitor wedges the key tools in your arsenal are spectrum analyzers and Graphic EQs, preferably a stereo unit. Once your stage and FOH are ready the next step is to track down where you are likely to trigger feedback. Using your Graphic EQ start sweeping up through each frequency to where you hear feedback building and then reduce that frequency by a few decibels. Use your judgement when deciding how much to take out, you don’t want to cut your mid frequencies out to the point where everyone sounds like they have a cold.
Your spectrum analyzer will provide a constant live feed and visible indicator of your aural landscape.
From here you can start setting up your individual feeds, reverbs, and delays. These simple starting points will make the difference of how much targeted sound you can deliver and how comfortable the act feels on stage. The better the monitor mix the better the performance. After all, you can’t sing in tune or play on time if you can’t hear yourself or everyone around you.
Blag spends his time between web development, IT, and audio. His background is oddly enough in the same things. Blag works in IT and is a contributing editor at Videomaker where he mainly focuses on audio.