28. 04. 2022 Charles Callaway Documentation

Making Your Own Video Tutorials, Part 8: It’s All About That Audio

So your video shooting and editing skills are at a high level now, and you’re comfortable and even confident appearing in your videos. You’ve acquired a good quality microphone, greatly improving the resulting audio. But down deep you know there are still some things about the sound you could improve.

I’ve already written a bit about audio, both its general role and giving some general audio recording advice. But here I want to go into more detail about how to improve the quality of your audio.

If you’re in the business of sound production, say for making professional music tracks and film audio, you’ve probably got a budget to match and an acoustic engineer or two on hand for whenever they’re needed. They’ll probably give you great advice, something like “It’s all about that bass”.

Of course for our simple home-grown YouTube tutorials, we just have a modest budget. But we also have some great learning resources available on the internet, and for free! Let me introduce you to some of it, with an eye towards as much gain with as little pain.

And all right, it’s about more than just that bass. It’s also where the bass is going.

Acoustics and Room Setup

Just as you may want to have a dedicated space to shoot your videos, you may also want to have a dedicated space to record the audio for them. Having two separate spaces works out if you’re never onscreen, but if you are, then they really need to be one and the same space.

Fortunately you can do both at the same time. Setting up the space (“treating” in audiophile speak) basically means eliminating two types of sources of noise: external and internal. External noise comes from outside the space, and you want to block or absorb it. Internal noise instead comes from the inside, and you want to reduce it by eliminating reflections of sound waves that can hit the microphone more than once.

The first is often called sound proofing, and it turns out that your options are limited: you can add a lot of mass to the walls to absorb noise, or put a lot of distance between you and any sources of noise. Both are rather impractical and get exponentially more expensive the more you try to isolate your recording space.

Nevertheless you can find some “solutions” like mass loaded vinyl to buy online. A better bet is to find the quietest place possible, and record during the quietest time possible, then either do multiple takes until you get one without any intrusions, or else edit out anything bad that does get through.

You have a lot more control over the interior surfaces, and here the name of the game is softening anything that is reflective and will produce echoes. This includes windows and doors as well as floors, but also other hard and smooth surfaces like the tops of desks and plastic flooring.

So here’s one case where the 1970’s may actually be more technologically advanced. If you’re like me you may remember shag carpeting, overstuffed chairs and pillows, and thick heavy drapes.

That all works, but more modern purveyors of “audio treatments” have their own vocabulary including terms like bass traps, monitors, and acoustic panels and diffusors. And they have a lot of (opinionated) ideas about what works and what doesn’t.

I’d like to also note that both approaches are sensitive to the frequency of the noise, where higher frequency sounds are easier to filter out and low bass sounds are very hard to stop.

There’s too much to go into any more detail here, so instead I’ve just outlined the general concepts above and given you a bunch of links so you can go as far down the rabbit hole as you desire. Be careful though, everyone in this space seems to want to sell you something.

Audio Recording

Once the room/space is ready, you can divide up the technologies and processes into two parts: preparing for the recording, and doing the actual recording itself.

In addition to going down the audio treatment rabbit hole, you can also go down the microphone rabbit hole. To keep up with our musical metaphors, Audiophiles gonna audiophile audiophile audiophile. (Perhaps I need to work on my lyric-writing skills…)

There are many different types in terms of construction and in terms of how they pick up different sounds in different places. Where sounds are picked up better or worse is determined by the microphone’s polar pattern. In general the best type for recording a single person talking is cardioid.

If you trust these people, then for best results you should also position the microphone about 6 inches (15cm) from your mouth and use a pop filter since cardioid mikes are especially sensitive to high frequency sounds from consonants like “p” and “t”. After you’ve positioned the microphone, try to keep your distance uniform, since moving closer to or farther from it will change how loud your voice sounds.

If you do decide to use a standalone microphone, be sure that the audio and video are synchronized during recording. It’s really, really difficult to try to align it later. I usually record with my external microphone hooked directly to the video camera. This automatically synchronizes the two, and you should double check a video camera has this capability before you buying.

The last preparation step is to make a test recording using your full setup. Then listen to it in silence with over-ear headphones to make sure the audio quality is what you expected. If not, make adjustments until you’re happy with it.

When you record, remember to check your volume levels and don’t speak so loud that it causes distortions in the audio. It’s also a given that you’ll make mistakes in anything longer than 2 minutes of speech, so be prepared ahead of time on how you’ll deal with it. The problem gets more difficult the more mistakes you make: you can’t tell just from looking at the audio waveform what’s a mistake and what’s a good take.

People who know more than me (but I’ll support them from my own experience) recommend that when you make a mistake, pause for a few seconds. This lets you easily see that something’s up just by looking at the waveform. I’d even suggest you create a fixed pattern, for instance, snapping your fingers twice near the microphone after a good take, and three after a bad take. It really speeds up the post-editing process.

Suppose though you may have made a mistake, but you’re not sure in real time how bad it was. You could either do a retake, or let it slide and fix it in post-editing. The issue here is which approach is more efficient. From my experience, it’s very cheap to do a retake, so that’s what I always do. After a certain number of retakes though (say 5), it becomes better to erase what you know are bad takes so you won’t have to sift through all of them later.

My final piece of advice is that if you don’t have a permanent recording space (we’re back to our modest budget here), then you’ll have to set up and tear down for every recording session. So before you tear it down, listen to your entire recording to ensure you’ve got everything you need, ideally with no post-editing required.

Post Editing

As you’ve probably guessed by now, I’m not a fan of audio post-editing or the expensive software you often need if you’ve got a lot of it to do. I prefer to use only the simple tools like muting out unwanted noises and breathing sounds, and fading in and out music and sound effects.

So the total amount of time I spend in post-editing is maybe 5 minutes per finished minute of video. Unless you’re a glutton for punishment, you should shoot for the same goal by using the advice in the sections above to eliminate any problems before they even make it to this stage.

Conclusion

So remember that our continuing assumption of a modest budget prevents us from doing a lot of fancy things to produce perfect audio. But we can still make some simple changes to our space that will produce major improvements, and we can still make some simple changes in how we conduct the recording session that will produce major improvements.

In this case you should remember the old 80/20 rule, which states that in general 20% of the causes contribute to 80% of the effects. If we take it to it’s logical conclusion, we can use just 20% of the work (as long as it’s the most important and relevant 20%) and still get 80% of the way to producing perfect audio. You can’t ask for much more than that on a modest budget.

Oh, and by the way, I’m sorry in advance.