Tommy can you hear me…or is my audio broken? How to get better sound on your Zoom calls from your home office.
It’s not a secret that I’m a huge audio nerd. My (non-virtual) Zoom background is a bunch of album covers, a record player (so I can play the albums that used to be in those covers), my
baby electric guitar and bass guitar. Oh and also a Lego Batmobile, because, again, nerd.
Audio is quite important for demos, but harder to manage than video. The main reason for this is that we can see our video in real-time while on a Zoom call, so we know what we look like – we can adjust if the lighting is bad, if the camera placement isn’t where it needs to be, or for any number of other potential issues that come up on video. But for audio, you’re relying on the person on the other side of the call to tell you if something is wrong, which they may or may not do.
For this article, we consulted with audio engineer and graphic designer (and a hell of a bass player) Brooklyn Fraser to get some tips on how to set up a room for the best possible sound.
First, let’s talk the physics of sound
We’ll get to the how, but first, let me give you some science behind why managing sound in a room is difficult.
Sound is a wave (in physics, not like the ocean or what happens randomly in the stands at baseball games), as is light – and can be measured by amplitude and wavelength. Amplitude is the size of the wave, and it impacts the intensity (volume or brightness) and wavelength is the length of each of the waves measured from the top of each wave (how much “information” is in each wave).
Let’s take a look at Nirvana’s Smells Like Teen Spirit:
This is just a few seconds, but you can probably get a sense of what’s happening. At the very beginning, it’s quiet, so the waves are smaller (amplitude) – and you can see exactly where Dave Grohl starts hitting the drums.
Let’s go even closer to a VERY (1/10 of a second) short clip, starting at 25.68 seconds:
On the left you can see Krist Novoselic’s bass line, and there’s more space between the tops of the waves (a longer wavelength, which is what you would see if only the bass is playing). But right when Kurt Cobain plays the 2 note guitar part before the lyrics, the wavelengths get shorter as there are higher notes (and there’s more “information” in those waves as you have bass, guitar and drums).
There’s a third concept which plays a part here, and it’s called attenuation. Attenuation is the reduction of the signal intensity, aka when it no longer becomes visible/audible. Signals with longer wavelength carry less information, but take longer to attenuate. For example, think AM/FM radio. FM radio waves have shorter wavelengths, which is why FM radio sounds better than AM, but it’s also why the signal doesn’t go as far. AM radio has a longer wavelength, so while there isn’t as much “information” in the signal (it sounds worse, particularly for music), it travels a lot farther – that’s why you can sometimes get AM radio signals from other cities at night.
As we see in our example, the bass line has a longer wavelength than when all 3 parts are together, which means that, when played through a speaker, the bass is going to be heard at a farther distance than all 3 parts. It’s the same reason that, when driving next to a car with a loud stereo and the windows closed, or when your neighbors have the music on too loud, you typically hear the bass but not much else – the bass signal goes farther before it attenuates.
Sound waves? Attenuation? What does this have to do with the sounds on a Zoom call or a home office?
We’re getting there.
Let’s compare lightwaves and soundwaves. Controlling light is not only easier because you can see it, but also because light interacts with surfaces differently than sound does.
Light interacts with whatever color object it comes into contact with – dark colors absorb light, light colors reflect it. Ever touch a dark car on a sunny day? The car is hot because the dark color is absorbing the light and converting it into heat. But ever have trouble looking at a snowy surface on a sunny day? White reflects light and doesn’t convert it to heat. This is also why darker color rooms tend to look “smaller” – the walls are absorbing the light.
How can you reduce those echoes on a Zoom call in a home office?
When we asked Brooklyn about reducing echoes for your Zoom calls (or any other recording), here’s what she told us: “Any time a flat surface is disrupted, it will either diffuse or absorb sound, depending on the material.”
Sound reflects off of pretty much any smooth surface. A quick science experiment – start playing music on your phone, and
drop it gently place it into an empty bucket. It’s going to get much louder, because the smooth surfaces in the bucket are reflecting the soundwaves. The bucket is echoing the sound. It’s also why echoes can be heard in a cave or a canyon – the sound is bouncing over all of the surfaces.
And, just like that cave, your office is also creating echoes. Walls, windows, picture frames, whiteboards – the more reflective the surface, the more the sound is going to bounce off of said surface, meaning the more echoes are going to be created. Those echoes are less noticeable to the human ear, but your microphone is going to pick up all of them. The key is to “deaden” the sound as much as possible.
Step 1 How to get better sound on your Zoom calls from your home office: Use what you already have
You probably have stuff in your house or apartment that could be great sound absorbers, you just have to place it all in your office (or wherever you’re having your calls).
Brooklyn’s advice – “Books, records and curtains are great sound absorbers. Thick curtains behind your desk will also help a lot.”
Have a closet with sliding doors? You’re one step closer to improving your sound. “If you keep both slides slid to the middle, so there are gaps on both sides, the closet will act as a bass trap.”
Step 2 How to get better sound on your Zoom calls from your home office: Get some sound absorption
Once you’ve exhausted your options for what you have, get some foam.
“Sound absorption panels on the walls and corners will help with mixing. You can get large packs of sound absorption foam on Amazon for cheap. 1 inch should be fine – 2 inches is probably overkill for most home offices. If you want something more professional looking for your video, there are tons of decorative panels on Etsy, which is more expensive but also really cool art.”
“To figure out where to place the foam – play some music with loud bass and walk around the room. That will help you find the right spot.”
Even before walking around the room, there are some spots that you will definitely have to cover.
“Put some foam behind your speakers to absorb the bass reflection from the wall. Square rooms can be tricky, and you want to make sure to add foam to each parallel wall so the sound is as balanced as possible.”
Step 3 How to get better sound on your Zoom calls from your home office: If you’re still getting an echo, cover the ceiling
“I used to use a piece of foam insulation, and attached 1in sound foam to it. It’s super light, so you can hang it with finishing line. You can also put foam directly the ceiling – either way, put it above your head at mixing position. Something like this (the Roominator Starter Kit from Auralex Acoustics) is the idea:”
Step 4 to getting better sound on your Zoom calls from your home office: Make a booth
When COVID first hit, lots of podcasters, particularly professional ones who are normally in a studio, talked about how they were now in a closet. From a pure acoustics perspective, you’re probably not going to find a better recording space in your house/apartment than a closet – it’s small, but your clothes absorb pretty much all of the sound.
It’s not great for visuals, but can do wonders for audio calls.
If you’re just looking to record better audio, you can make a small recording booth:
“For voiceover recording, you could set up a booth with blankets. That’s what I used to do. A small, 3 walled blanket booth made of nice stands. It’s not the most elegant solution and it’s not permanent, but it works.”
How I redid my own home office for better sound on my Zoom calls:
Taking Brooklyn’s advice, I got some sound absorption panels (they were cheap – $45 for 48 panels, plus some 3M command poster strips to hang them) and put them on 3 walls in my office, plus the corners.
The main wall, which is behind me when I talk (and behind my speakers), is now mostly covered with foam:
The closet on the right is now a bass trap, and there’s also some foam above the door (especially as that part of the wall is a bit recessed, which can make it an echo chamber).
The left wall has some foam as it’s across from the closet, and there’s some foam in the corners. Also, you can see the scribbles on the whiteboard that were put there by a toddler who thought that the whiteboard is amazing.
The back wall didn’t need much – just that foam in the corner.
That’s it – just a few easy steps and your Zoom calls will sound better
Keep checking back for more tips on home office setup and remote demoing. Soon I’ll talk about the desk and everything I did there (ring light, monitor stand, standing desk riser, etc).
And, of course, if you want advice for your own home office, or you just want to talk about demos (or snacks), don’t hesitate to get in touch.