Importance

Taking extra care to make your audio excellent will help immerse your audience in your video, impacting how clearly your message comes across. 

Target Audience 

• Videographers and Photographers 

How-To  

Audio Capture 

• Choosing location: Make sure the location you are filming in is as quiet and non-echoic as you can. Loud white noise or unwanted background sounds and conversation distract from what you want your audience to hear. Think about the time of day you will be filming as well—a space that’s quiet during a location scout might sound different during a passing period or if nearby construction starts up again. 
• Microphones: There are multiple options for types of microphones to capture your audio based on what you’re trying to accomplish. Generally, getting your microphone closer to your subject will give you cleaner, richer audio with less background noise, even if your microphone is just a smart phone placed just outside of a shot. Most cameras will record in-camera audio; avoid using it in your final mix if possible. In-camera audio, or scratch audio, can be very useful for syncing your better audio to your video if you record it separately. 
• Shotgun microphones: Shotgun microphones are a good choice for interviews and picking up targeted sounds because they are very directional, meaning they reject sounds outside of their pickup patterns. They capture a large range of frequencies, resulting in natural, well-rounded audio. If possible, place your microphone around 2-3 feet away from your subject and point it at the subject’s collarbone to capture words clearly without getting excessive mouth sounds and plosives. 
• Lavalier microphones: Lavalier microphones are small and are usually clipped onto the subject around the collarbone area. They are a good choice if your subject moves around or the framing of your shot is really wide since they are unobtrusive and can be wireless. They can also be a good choice if the wind or other background noises are a factor as they are closer to the speaker than shotgun mics. The main downside to this type of microphone is that depth, richness and overall quality are not quite as good as other types of microphones. 
• Studio microphones: Studio microphones work best if you are recording in a studio where seeing the microphone in the frame isn’t an issue. They can be a good choice for recording podcasts, podcast-style lectures or voiceover. To get the best performance out of a studio microphone, you want your subject to speak directly into the mic around an inch or two away. 

Recording 

• Listen as you record: One very important part of recording audio is listening to the audio as you get it. There are all kinds of things that can go wrong that might not be obvious if you’re not listening—rustling from hair against a lavalier mic, interference from the channel you select on a wireless mic, wind noise,  etc. It’s much easier to correct a big problem during recording than it is in post-production. 
• Capture audible audio: The other most important part of recording audio is making sure what you’re capturing is audible. Recorders vary, but keeping the main part of your mix between -18 to -12 decibels is a good range to aim for. You never want your mix to peak at or above 0 dB, which is the point where audio “clips” or distorts. 

Dialogue Editing 

• Programs: Most of the tools and functionality needed for audio editing exist within video editors already. However, there are options if you’re looking for an audio-only editor. Here are our top couple of free recommendations: 

• • Adobe Creative Cloud: Adobe Creative Cloud is available for free for all faculty, staff, and students at Illinois. This includes leading video editor Premiere Pro and audio editor Audition, among other things. 
  • DaVinci Resolve: Resolve is a robust video editor with most of its features available for free. It has especially advanced color tools. 

• Fix inconsistencies: Once your audio is synced to your shots and your video is put together, you’ll want to listen to your dialogue track and identify anything that stands out to you. Maybe there’s a breath in an awkward spot, maybe there’s a crash in the background, maybe there’s a gap with no audio that sounds jarring because the rest of the mix has room tone that suddenly disappears. Many problems can be fixed by trimming/extending audio, adding fades from one clip to another or replacing a small section with something else entirely, such as room tone from a different time in an interview or the first syllable of a word from a different take. This takes some practice and patience, but leads to a much cleaner-sounding video in the end. 
• Reduce background noise: Sometimes background noise is unavoidable. Most editing programs have in-house denoisers to help remove room tone, pops and clicks to varying degrees of success. If the in-house tools don’t seem to be working for your situation, there are a few plugins available for purchase with more advanced algorithms that tend to lead to better results. We’d recommend: 

• • Clarity Vx from Waves 
  • iZotope RX Elements from Native Instruments 

Music 

• Most videos benefit from background music to reinforce the tone and mood of the piece, but finding the right song at an affordable price can be tricky. Here are a few options for university employees: 

• • Storyblocks: The university has an enterprise license with Storyblocks that includes all kinds of music and sound effects (among other non-audio related things).
    
  • Universal Production Music: Strategic Communications and Marketing has a license with Universal Production Music that is available for U. of I. employees. However, only StratCom has the ability to download from the site. If you find songs on this site you’d like to use, please contact videoservices@illinois.edu and someone from the Video Services team will download the music and send it to you.
    
  • Public Domain: Any song in the public domain can be used by anyone for any purpose. Note: Public domain is not the same as “royalty-free.” Royalty-free music is not usually free. 

Audio Mixing/Mastering 

• Mixing: Mixing is the process of balancing each audio element to work alongside one another as a cohesive piece.
  
• Balancing volume: Start with the track you want to be the loudest, which is usually the dialogue track. Adjust the volume levels on each clip of your dialogue track until they sound consistently good the whole way through the video. A good range for dialogue peaks is usually between -12 to -6 dB, with the very loudest peaks definitely under 0 dB to avoid distortion. You’ll want to adjust your other tracks, such as music levels, off of this main track. A good starting point for music levels might be around -20 dB or so, but will vary greatly depending on the mood of the piece, the types of instruments in the mix and the complexity of the song. Keep tackling additional tracks until you’ve gotten through all the audio.
  
• Compression: Sometimes an audio element might get too loud or too quiet and its peaks might not fit in the decibel range you’re aiming for. In that case, you’ll want to reduce the dynamic range of the spot or the whole track with compression. If there are only a few spots to fix, it’s simple to do this manually, with keyframes changing the volume or gain of the problem spot. If there are many spots to fix, you’ll want to look at the in-house compression tools of your program to help reduce the dynamic range of the whole clip or track. Compressing can allow you to go back and adjust volume balance by giving you more headroom to work with if you otherwise wouldn’t have been able to turn the levels up without clipping.
• Equalization: An equalizer is a very powerful tool that allows you to adjust the volume of individual audio frequencies. Within the frequency spectrum, human hearing ranges from about 20 Hz to 20,000 Hz and different sounds and instruments exist in different frequency ranges within this spectrum. There are many applications for this tool, but here are a few of the most common for Illinois videos:
  • High-Pass and Low-Pass Filters: If you have a very low rumble or a high-pitched noise in your audio that doesn’t overlap a frequency you want to keep, such as a voice, you can use these types of filters to get rid of the problematic parts of the spectrum while allowing high or low frequencies to pass through.
  • Creating Space in Music: When you want to increase the level of your music but are worried that the dialogue will become muddled, adjusting music equalization can be the answer. Typical lower adult voices have a fundamental frequency from 85 to 155 Hz and typical higher adult voices have a fundamental frequency from 165 to 255 Hz. Lowering the volume in the corresponding spot of your music’s frequency range removes some of audio that the voices are competing with, allowing you to increase the volume of the music without muddling the vocal range.
  • Sweetening Dialogue: Sweetening involves subtly boosting frequencies that sound nice and subtly cutting frequencies that are overpowering. Editing programs will often have an in-house tool such as a vocal enhancer that will make its best guess as to what needs to be sweetened, but you can also do this manually for a more customized mix. Listen to your track and identify what you’d like to hear more of. In general, boosting lower frequencies can add depth and richness to a voice, boosting mid frequencies can add warmth and boosting high frequencies can add clarity. Each voice is different and small changes go a long way, so experiment, keep subtlety in mind, and keep listening to your track as you go. 
• Mastering: Mastering is the process of balancing the whole mix after mixing is complete. One of the main purposes of this step is to make sure that your video will be consistent with other videos, as well as across different platforms and sound systems. This step used to be much more critical when there were more technical barriers for distribution mediums. If your mix is already in a good spot, you might not notice that much of a difference if you skip this step.  Mastering also involves EQ, compression and volume, just applied to the entire mix instead a single clip or track.
• Loudness: One key difference is that mastering also takes into account loudness through LUFS. Loudness is based on how our brains perceive sound, which includes volume, but also other elements like how different frequencies sound to the ear. LUFS measures average perceived loudness across a mix, again taking into account more than just volume. Using the average of the mix gives you a way to see if your video’s loudness falls  within a good range. If not, you can continue tweaking your settings until everything sounds the way you want it to sound.
  • Streaming platforms have standard LUFS normalization levels so that jumping from one video to the next isn’t jarring. If your video doesn’t fall within the standard, the platforms will adjust your audio so that it does. 

Tips and Tricks: 

• Wind noise can ruin outdoor audio capture. Bringing along a “dead cat” or another type of windscreen for outdoor shoots can make your life much easier.
• Different microphones and different environments all have different sound profiles. Keep in mind that switching between something like a tinny microphone and a super bassy microphone might be jarring to audiences.
• When mixing your audio, it can be really helpful to listen to your mix at different volumes on your computer. If you turn your computer volume down to almost nothing and still hear music, but also hear what is being said clearly, the mix will probably be pretty clear for someone listening at any volume on any device. 

Contact 

Video Services, Strategic Communications and Marketing, videoservices@illinois.edu