• Tom Kelly

6. Room Reverberations and Why They're More Damaging to your Podcast Than You Think



I've said it over and over and over again, your audio is mainly defined by your microphone technique and your recording environment. Last week we recorded mic technique, so here we are with the environment!


Most podcasters know that reverberations aren't good for your podcast, but a lot of the knowledge ends there, and a ton of myths and bad information fills in the rest of the gaps.

Spend 5 minutes in any Facebook group, any forum, and podcast related sub-reddit in existence and you'll come across phrases like "make sure to podcast in a small space" and "throw some pillows behind your microphone to create a vocal booth". Let me be the first to tell you, this is pretty bad information that stems from only understanding 5% of the problem.


Reverberations are caused when a sound (ie. your voice) bounces off your walls over and over again, hundreds of times a second, and each time it bounces off the wall, you hear that instance of the sound, and again milliseconds later when it bounces back, and milliseconds later when it bounces back again, etc. True, smaller rooms will create a shorter reverb tail, but it doesn't necessarily create less reverb. And a pillow might absorb SOME sound, but it's neither dense enough, deep enough, or voluminous enough to really make any kind of audible difference.




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The problem with reverberations in your podcast is three-fold.



It doesn't fit the medium

Think of any podcast that objectively has high production value: NPR, Gimlet, most of Relay FM, it's a dry sound, meaning no reverberations. Most of broadcast is. That's just the space we exist in.


It makes it harder to hide edits

When your reverb tail takes half a second to decay, it's REALLY hard to edit the "um*mouth click*" out of "andummmmm*mouth click*it's not a big deal. We're going to be cutting off the reverb tail of the "um" which causes a harsh edit, and the reverb tail from the mouth click is going to trail into the "it's" even after removing the click itself. You'll hear these weird artifacts of sounds that once were tailing into the sound you want to stick around.


It makes it harder to mix the audio

The problem I had with my cohosts audio of my other music podcast Reminiscent was he lined up a bunch of coat racks and hoodies and all kinds of "soft" objects all around where he recorded, but it did nothing for the very low frequencies of his voice. We ended up with a pretty boom 125Hz reverberation problem that a made his voice muddy, but when I tried to EQ out that frequency, we lost all the depth and the warmth of his voice. If I tried to keep the warmth of his voice in, the reverb made it muddy. There was no middle ground because the reverberations and early reflections were short enough to sum themselves with the direct sound of his voice, making it impossible to distinguish and separate the two.


I touched on it a little bit, but these pillows, 1" foam panels, and other free "hacks" simply aren't working because the laws of physics are unwavering. Different frequencies have different wavelengths, meaning cycles of compressions and rarefactions, or high and low pressure segments over time, and the low frequencies are INSANELY LONG and take a huge amount of energy conversion to fully absorb them. When it comes to wedge foam panels, the sound is absorbed by converting the sound pressure waves into minuscule amounts of heat. Since energy can neither be created nor destroyed, we have to change it's form, and once it's converted to heat, the energy is dissipated and won't be sent back to the microphone in the form of a reflection. 1" foam panels are nether dense enough or deep enough to capture any sound below 800 Hz or so, and the human voice actually possesses a lot of power below 800Hz. So if we cover the walls of our walk in closets with 1" foam panels, 2 things happen. Only the higher frequencies are absorbed, essentially throwing a high pass filter on the reverb, but these smaller rooms (think of a small room as 10ftx10ft and under) have an incredible way of boosting the low frequency response by a phenomenon called "modes", which are essentially a summing of wavelengths that causes a boost in certain frequencies, depending on the room volume and shape. So when we're in a small space with a high pass filter on our reverb, we end up with a SUPER boomy environment that's going to overwhelm the hell out of your listeners ears.



So what do we do? We need broadband absorption. At the VERY LEAST, upgrade to 3" wedge foam panels, but the better option is to build or build acoustic panels, which are essentially fabric wrapped insulation. More on this at a later date, but these will absorb frequencies as low as 100Hz and are much more effective at absorbing sound as a whole.


The best way I can put it is if you're a 190 pound man who's looking to jump from a a tree into a pile of leaves, you'll break your tailbone if you think you can cannonball into a 1 foot tall pile of leaves. You may need up to 5 feet of leaves to absorb your downward momentum as you jump from the tree. Now, a 40 pound child could jump from the same brand and maybe only require a 2 foot pile of leaves because they contain significantly less mass than the grown adult, therefore requiring less "stopping power" to absorb their fall. It's the same with lower frequencies. While a 9,000 Hz frequency has a wavelength of only 1.5 inches, a 120 Hz frequency takes about 9.5 feet complete a cycle of compression and rarefaction. THAT'S why lower frequencies are so hard to control. When you're designing a studio space for music production and you have to worry about 20Hz, good luck with that 56.5 foot wavelength!


So where do we go from here? Really think about investing some money into your room. It's easy to dream about spending $450 on a brand new Shure SM7b, but I promise if you only had $450 to spend, I'd buy a Shure SM58 for $100 and invest $350 into treating your environment. You'll spend the same amount of money, and you'll sound WAY better with the $100 mic in a great sounding room.


If you've listened to the podcast and you want to learn even more about the topic, check out the video I recently put out that covers some of the same issues but in a different light.


Links:


My YouTube Video on Reverberations

What is Reverberation?

Relay.fm

Haas Effect

Frequency Range of the Human Voice

Wavelengths in our Room

Noise Reduction Coefficient Charts

Room Modes

My YouTube Video on Phasing

Room EQ Wizard


Closing Song:

Broad by David Cutter

http://www.davidcuttermusic.com/ @dcuttermusic




My Signal Chain


Hardware:

Audio Interface: Apogee Ensemble

Microphone: Shure SM7b

Mic Stand: Rode PS1A Boom Arm

XLR Cable: Handmade...


Software:

IzoTope RX6 De-Mouth Click

FabFilter ProQ3

Waves LinMB

Waves Vocal Rider

IzoTope RX6 Voice De-Noise

Waves L2 Limiter

Waves WLM Meter

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For more info, or to ask any questions, check out my website and reach out to hello@cleancutaudio.com


Full transcript:



Hello friends! My name is Tom Kelly, this is Clean Cut Audio, and this week on the podcast, we're talking about reverberations, why they're so much worse than you think, and why nailing those moving blankets to the wall isn't doing a single thing. All right Let. Us. DO IT!


Alright, so we're kind of doing this podcast in a linear progression of the fundamentals. What do you need to know in order to achieve a great recording? I really want to go after the low hanging fruit and teach the principles that are required for capturing great sound. Because again, you can have an $18,000 microphone but if your technique and your room is bad, it's going to sound just as bad as any other microphone in those situations.


A $25 microphone, while not recommended, will sound better in a well-treated room with proper mic technique than a very expensive microphone with bad technique in a bad room. Got it? Good. Never forget it. It is the most important thing when it comes to producing great audio.


Last week we talked about microphone technique, so it's only fitting that this week we really get into the environment, specifically reverberations. I did a 32 or so minute video on my YouTube channel youtube.cleancutaudio.com that's going to parallel a bit of what I'm saying in this episode. It's going to have a little more visuals in the video, but either way, this episode is going to be supplemental to the video. You can get something unique out of both. We're going to do some listening exercises and I'm pretty excited for it because a lot of people think like, oh, a little reverberation isn't that bad, not that harmful. But it is so damaging and most people don't realize it, and they don't realize that the things they are doing to try to fix the issues absolutely are not working, and can in fact make matters worse. That's going to be the last topic of this episode because we need to build in order to get there.


So the very first thing we need to talk about is what is reverberation? In the simplest of terms, it is your voice coming out of your mouth, some of that hits the microphone, but your voice travels in every direction all the time. It doesn't come straight out and it goes everywhere, and a lot of that is bouncing off the walls, and then it's bouncing off another wall, then it's bouncing off another wall, and it just does this. And a couple things affect how long or how pronounced this reverberation happens: room size and absorption. And there's a couple myths in both of those that we will be busting as well, but reverberation in your podcast happens when your voice goes straight into the mic. Let's say it bounces off a wall once, some goes into the microphone some of it will bounce off another wall, and then some of that will go into the microphone. But some of that second bounce will then have a third bounce, and then some of that goes into the microphone. And this happens like hundreds or thousands of times a second because of the speed of sound, which is 330 meters per second, something like that. So this is happening very quickly and it happens a lot so we need to mitigate this in our environments with absorption methods.


But the first thing about reverberation is it lowers the intelligibility of your podcast. The louder the reverberation is, and the longer the reverberation lasts, the intelligibility goes down. We're doing these podcasts because we have something important to say that we want people to hear. And again, the responsibility comes on us, the podcasters, to provide our listeners with the easiest to understand audio possible. We are asking them for an enormous amount of their time. Other media outlets would kill for five minutes of someone's attention. And oftentimes we're asking for 20, 30, 60, 90 minutes of someone's attention a week. We want to make sure that we make it as easy as possible for them to pay attention. If your audio isn't very intelligible, meaning it's hard to understand, they're going to tune out, or they're going to miss some of the information as they're trying to decode what is going on in your audio. And that's why this is important.


It would be like if a painter just finished their oil painting and as you were on your way to look at it and really explore its beauty, and the depth, and all the color, and really get a good look at this painting. And then they took their hand and just smeared the whole thing top to bottom. Now we'd still have some of the same colors, maybe a similar composition. We might be able to tell what was happening depending on how big of a smear it was or how hard they pushed their hand into the painting as they smeared it. But you can already see that you're losing a lot of the information. You're losing a lot of the beauty unless this is some weird performance art piece, which I've never really understood anyways, but we want this painting to be as clear as possible so they can really understand how much work went into it, understand the content, really get as much value out of it. We don't want to be smearing our audio with reverberations, and that's really kind of what is happening here. You're just muddying up the whole thing.


Not only is it bad for the intelligibility, but there's three other things that it affects. Three other reasons why it's bad. One, it makes it much, much harder to transparently edit a signal that has reverberation in it. We're going to listen to some examples. It makes it very difficult for an edit to go unnoticed, and again, a good edit is one that people don't even know exists. The second thing is it actually makes mixing very, very difficult. We run into problems with these lower frequencies. We're going to go into a little bit of the science of that along with some examples, but that is a big one as well, and it's one that most people don't think of, and it's also something that people don't typically hear because that is something that happens with very short reverberation times and early reflections. And these are extremely damaging.


And it's a very little known thing and it's something that I didn't realize my cohost had an issue with for years until my brain started working one day and I realized what's really going on here. There's a deeper root to all of this. And we couldn't fix it with a different microphone, we couldn't fix it with any gear, it had to be an environmental change that needed to happen.


And the last thing is it just doesn't fit the genre. I mean, think of your favorite podcast that's produced well: anything coming from NPR, anything coming from Gimlet, or Relay FM, one of my favorite networks. That's just not the way podcasts are.


I mean, if we're recording music, sure, we can have a little bit of reverberation to build an environment, to build a space for all these instruments to live in. There needs to be some distance in order to separate things. But since this is just one voice, maybe two, three voices. We don't want space. We just want a clear signal.


You want it to be dry, and what is dry? It just means lacking reverberation or lacking anything added to it. So if someone says, "Oh, that sounds really wet", it would be a really reverberant signal. Reverberant like (reverberant signal) this where it trails on forever and ever. It's a very wet sound.


Alright. And when it comes to editing, you know, I'm a professional editor. That's what I do for a living. edit podcast for clients. Some people just don't really want to put the time and attention into the audio, and a part of me gets it. Because they're... Well, I get it, but I'm fighting against it at the moment. I think there are no set standards. It's a big trope that audio doesn't really matter, so just put it out there, put it out to the world. The world needs to hear it. They'll listen. They'll suffer through it because your content is so good. I'm trying to change that as gently as I can. I don't want anyone to feel bad about their audio quality because it's iterative. I mean, you can always get better. I can get better. I can get tremendously better, but I don't want anyone to feel bad if their podcast is reverberant. We're trying to fix that. I'm glad you're here. If you're here, I'm glad you're here. If you're trying to figure out a solution. That is the best display of humanity I can think of is just trying to get better. So I applaud you. If your podcast is very reverberant and you're here to try to fix it, welcome. I'm happy to help you out.


Alright, we're in the stairwell and we can already hear a significant change in the audio quality. This is the really fun intersection between microphone, technique, and your environment. I've mentioned it before, but I record on a Shure SM7b , which after doing the transcriptions of this show, I realized, I keep saying "shore" it's a Shure SM7b, but ideally we want to get pretty close to this microphone.


And we can hear that if I back up about three inches off the mic in the way that I was doing the mic technique episode last week, it changed the tonal quality of the sound a little bit. But when we are in less than ideal recording environments, the further you get from the mic, the more present, the louder all of these bad reflections get. Because when you're nice and close to the mic, the amplitude of your voice kind of overpowers it. It masks a lot of the room sound. I mean, it probably sounds a lot worse to my ears than it does in the recording, but again, if we back up about a foot, this is like how bad the room actually sounds. And when you're in a bad environment, you're going to have a bad sound. I'm using all the same equipment that I do in the normal recordings. All I did was take a hundred foot XLR cable and start walking through the house. I mean, we can really hear the difference in this quality.


But a lot of these people will send me audio, I've had up to like a half of a second of a reverb tail. And reverb is different than delay. Some people confuse the two. Delay is like echo, echo, echo, echo echo, echo. Where it's repeating the transient, it's repeating the whole phrase, but a reverberation would be, think of a hallway where it's like, echooooooooo. And it slowly fades out over time. It's a time based thing and that's how you separate the two notions of reverb and delay. And then there's other parts of reverb that we're gonna touch on, but not a ton.


But I'll have these half second reverb tails and what makes this so difficult is if they want me to edit out their ums, and their mouth clicks, and "like, kinda, you know, um, yeah, you know, I think, ah, well for me it's kind of like, well, when, you know" all of that stuff, if you want me to get rid of it, there's not a long enough pause between what I'm removing and the stuff that needs to stay in. So when we have a reverb tail, that is bleeding into the next word. So if I cut a mouth click and it tails into the next word, you're going to inherently just have some reverb tail from a mouth click, that doesn't exist anymore, that is cutting into the beginning of your word, and it's going to create a really kind of jarring sound that's going to be noticeable. Listeners will hear it, and it's a huge problem because I can't really do anything about it. I can try to make a longer crossfade so it's not so loud, but it's a really difficult thing to get rid of.


I'm going to play an audio sample of what was in my YouTube video right now to demonstrate how easy it is to edit a dry signal versus a wet signal. tIf you want to see the whole video, it is at youtube.cleancutaudio.com. The video is called Rreverberations are Ruining Your Podcast, and Why it's Worse Than you Think." All right, I'm going to be editing this signal that was recorded dry, and then we added some reverb to it. And by we, I mean myself. I don't know why I just said that, but you're going to hear how much easier it is to edit the dry signal than it is the wet one. And how much more obvious it is that there was a weird edit in the wet signal. Let's listen. Here's the dry before and after.


(Editing example) And um, it's not a big deal. And it's not a big deal.


And here is the wet before and after.


(Editing example)


And it's not a big deal.


So you heard in that little sample there that, especially those mouth clicks, they roll into the next word and it's hard to work around that. If you have a dry sample, when you cut the word, you cut everything. When you cut the mouth click, it's all gone. There is no residue, there are no artifacts left over from something that once was. And if you're editing your show, you should always be editing for the most seamless and the most natural sound possible. I'm going to do an episode on the ethics of editing because I truly believe that a lot of people, probably most people, myself included at one point, over edited. And I don't want that to be a thing. But if nothing else, I don't want you to be able to hear edits. When you have reverberations, you are cutting off your reverb tail short, which causes a very noticeable edit point. And there's got to be an edit point when that reverberation tail from a cut word is now entering the scene unannounced, and artifacting itself all over the rest of your speech. It makes it very difficult to edit.


And the next thing, this one is kind of subtle. It takes a very keen and a very trained ear to figure out what is happening with early reflections and muddy reverberation. It's easy to tell when it's a very long reverb tail. It's easy to separate the source signal from the reverberations. Let me say that again. Reverberations. I'm trying to work on not mumbling. Gosh, I'm not a presenter, but anyway. There is something called the Haas Effect. It was discovered by Helmut Haas in the late '40s, and it's essentially when two signals are happening so closely to each other, but still slightly out of time, that it's like beyond the time difference that your brain can differentiate and it sums itself together as one signal.


Now with reverberations, we have the early reflections. Like I said before, some of your voice is got to hit the wall once, come into the microphone. Some's going to hit twice, come into the microphone, some's going to hit three times, come into the microphone. There's those very early reflections. Most things in audio are very literal. Those very early reflections are sometimes harder to manage when we don't have proper absorption tactics and materials, and they're also hard to hear because your brain tends to sum them together.


Now my cohost, I love this dude to death, and he works so hard, so bloody hard to get a signal that I'm happy with. And every week he's trying out something new. He takes my criticisms so well. But basically we're both kind of balling on a budget and he doesn't have the proper sound absorption, so he's trying to improvise with what he has on hand. He has t-shirts, and sweaters, and pillows all around his microphone. He has coat racks against the wall to try to absorb some stuff, but it's just not dense enough and it's not thick enough to absorb everything, especially the low frequencies.


It does chop off a ton of that reverb tail, but we still have the early reflections problem. And what's happening is he's absorbing and scattering some of the high end in his voice. And again, the frequencies, a very high frequency is think of, I'm going to boost some of the highs of my voice right now. So it's kind of this airy, higher pitched stuff that was like, pitch, it's a frequency spectrum. And then a very low frequency, I'm going to boost the low frequencies for just a very small amount because it gets fatiguing.


So it's easier to absorb high frequencies than low frequencies. And I keep saying this, we're going to talk about that in a little bit, but what we have is his low frequency, early reflections are summing together with the sound of his voice. And what I'm left with is kind of a muddy in a very boomy signal. Now you could say, Tom, just EQ that out, right? Just cut some of those lows, cut around 120 hertz and you should be good to go. And that's what I do every week, but the issue, is the reverberations are boomy and muddy, his voice is not. So when I cut 120 hertz, I want to just get rid of the reverb that's in that range, but I'm actually now cutting a lot of the power out of his voice. And it's been very, I mean, it has been extremely difficult to find an EQ curve that I'm happy with because if I cut as much of that reverberation as I want to, I'm losing a lot of the depth of his voice. And if I leave the depth of his voice, and now I have the boominess from the room. And I can't use IzoTope de-reverb on this because the reverb is not bad enough to be captured by that plugin. It's summing together into what just sounds like his voice, but I know from years of ear training that there is an issue with the low end of the early reflections.


So we have reverberations that are damaging to mixing and editing. So what do we do about it? I mean, we need to have a way to get rid of these things, and this is the unfortunate part. I see a lot of podcast gurus, I see a lot of randos on Facebook saying, "Eh, just put a pillow behind your microphone, or nail some moving blankets to the wall, buy some of that 1" foam on Amazon that's like 50 cents for a one foot by one foot sheet and you're good to go. I'm very sorry to announce that you were not good to go. This stuff is not going to be effective, and let me explain why. We have to talk a little bit about the math and the physics of acoustics. It's going to be so low level that I know you're all going to comprehend it.


As I mentioned earlier, we have a frequency spectrum. We have the very low lows and the very high highs. The average human hearing range is 20 to 20, meaning 20 hertz to 20 kilohertz. As we get older we start hearing less of those high end ranges, so it might be closer to 14kHz. Those are those beeps, raise your hand, raise your right hand if it's in your right ear. Some of them we can't hear because our hearing just kind of degrades over time. I mean, being a human is a degenerative process, so we lose our hearing over time. Take advantage of it while you have it, kids. But the thing is, in order for sound to be absorbed, we need two things. We need depth and we need density.


So what does means is sound travels as a wave. It is a series of compressions and rarefactions, high pressure and low pressure waves that move through, in our case, air. It has to move through a medium, that's why there's no sound in space. There's no air particles to move with the energy, the pressure waves coming from your mouth.


So in order to absorb this, we need, let's talk about the wedge foam. For example, I have 48 square feet of three inch wedge foam on my walls. It's not ideal, it's not perfect, but it's doing a much better job than the one inch foam because of the depth. We absorb sound in these open cell panels, these wedge foam panels, because if you look really closely, there are tiny holes covering every inch of the surface area of these panels.


What happens is the pressure wave of your voice that's moving these air particles, they are being caught in these little open cells and there's nowhere for them to move, and then it's converted into heat because again, energy can neither be created nor destroyed, it can only change forms, so we have to turn air pressure into heat.


And these higher frequencies, they're easier to absorb. It's a much smaller wavelength, so if we have a series of high pressure and low pressure, these happen over time, cycles per second. The lower end of the frequency spectrum, the 20 hertz range. The wavelengths are about 15 to 20 no, I think it's like 35 feet long. They are insanely long. It takes 35 feet for this signal to complete a full cycle, a full wavelength from compression to rarefaction back to compression. I can't possibly get into all of this in this episode. I will post a link in the show notes to something that can better explain this. You can find the show notes at cleancutaudio.com/podcast/6, but just know that lower frequencies are insanely longer wavelengths and it takes way more to deaden in these because there's so much energy, and they're so long that a one inch panel, it's going to bounce right off that. It might take a little bit of a hit, but it's basically going to act like that panel is not even there. Now, 20 kilohertz, this is a very, very short wavelength and the depth of a one inch foam panel is longer than the wavelength of 20 kilohertz, possibly even longer than the wavelength of five kilohertz. I'd have to look that up, but basically the thicker, the deeper these panels are, the lower frequency they can absorb because it is closer to the frequency of that wavelength. We can also talk about quarter wavelengths. We're not going to, but, basically, you don't need a 35 foot foam panel to capture a 35 foot wavelength of 20 hertz or whatever.


Hey, I'm just breaking in after the fact here. I wanted to clarify that a 20 hertz wavelength is 56.5 feet. I was thinking of 30 hertz, which is 37.7 feet. All right, back to the show.


But with these one inch foam panels that everyone recommends, we have to talk a little bit about the noise reduction coefficient. What this means is what percentage of this frequency is absorbed by this panel. I'll have some charts in the show notes for this episode as well, but, with more depth, you have a higher noise reduction coefficient or NRC, so three inch wedge foam is going to be able to absorb up to 60% of like 250 hertz, whereas a one inch foam panel will absorb maybe 5% or 10% of that same frequency range. Same material, just two inches thicker than the other foam.


Now we don't have like an enormous amount of 250 hertz in our voice, but there is some. And like what happens with my buddy's audio, it's being bounced off and it comes back, and it combines with his signal, and it gets muddy. It gets way muddier than it needs to be, and than it would be if we had proper absorption in the room. But alas, we do not, because he's hanging up sweaters and stuff. And most sound is going to pass right through a sweater. It doesn't care. It's not enough of a barrier. So when we're nailing our moving blankets to the wall, it's not really doing anything. It's going to capture those very high frequencies and the higher frequency reverberations are easier to hear. So to our ears, it might sound like it's doing a lot, but it's really not in the grand scheme of things.


We need broadband absorption. And this is going to be Owens-Corning's 703 fiberglass insulatio, or Roxul, the Rockwool Fafe and Sound in a fabric panel, or much, much deeper wedge foam. This is going to capture more of those lower frequencies, just more of everything in general, not just the lows, but everything. It's going to do a much better job. The other part of this is there's a myth that if you go into a smaller room, you will have less reverberations. It's kind of a partial truth, but it is so partial that it doesn't even matter anymore.


So, here's the thing about a smaller room. We might get a shorter reverberation time, but it doesn't mean that we'll have less reverberation. The second thing to this is we talked about phasing on a YouTube video a couple of weeks ago, and basically what you have is, as these signals are coming from your voice, bouncing off the wall and they meet again in the middle or wherever else, they interact with each other. And some of these waveforms are causing cancellations of frequencies and others are causing a boost in frequencies, and a boost is called a room mode.


Now, in a smaller room, our room mode changes into a frequency of, let's say 120 hertz. If your in your closet, you're going to get a very big boost of low frequencies around 120, 150 maybe 200 hertz, and this doubles the damage when we're putting one inch foam panels in a room that's already boosting the low end.


Now we have panels that are cutting the high end, which means even more low end so we're boosting the low end and cutting out the high end, and we're left with a very, very boomy sound. And your t-shirts in the closet aren't going to do a lot of good. They'll do something, but it's not going to capture a lot of the low end. And when you're in a small room, I heard someone say they recorded in their bathroom because they heard someone say you want to record in the smallest room possible. And this was such a half truth that it caused them to capture some of the worst audio I've ever heard because they went to a small room. And if you've ever said "hello" in the shower, you know how weird it sounds in there. It is a travesty that someone was led to believe they would get a good sound in their bathroom because it was the smallest room in the house.


So to kind of sum this up, it's really hard to talk about this stuff I'm finding without visuals. So again, there is the YouTube channel, but lower frequency is have a much longer wavelength that require a deeper material to capture, to absorb it. I mean, it's like, think of it this way. If you are 190 pound man and you want to jump out of a tree into a pile of leaves, the amount of leaves it's going to take to absorb the blow is going to be substantial. You can't cannonball into a one inch pile of leaves and not expect to break your tailbone. Now, if that pile of leaves is five feet tall. It will absorb you on the way down so that you don't come crushing into the ground. We can kind of think of audio this way. I just came up with that metaphor on the spot so I hope that a holds water, but we can think of... What does a child way, I don't know. I don't have kids. 40 pounds. Let's say a 40 pound girl jumps out of the tree. Her pile of leaves can be smaller than the 190 pound man because her body doesn't have as much inertia and force and energy hurdling towards the earth. So the pile of leaves can maybe be two feet deep so that she doesn't break her tailbone on the earth. But the 190 pound man is going to need more depth in order to kind of absorb the blow.


You can kind of think about it that way. Again, that's not the full picture, and I don't have a master's degree in acoustical engineering, so I don't want to speak on a level that is significantly beyond my understanding, but just know that we need dept, we need density, we need broadband absorption. We need a material that can absorb all of these frequencies. Because if you have too small of a panel, you're just EQing out the high end. We need something that can turn the volume down entirely on these reverberations.


Now you've heard my stairwell, we've all become intimate cause you've heard the rooms in my house, you feel like you're here with me, we're about to put on some popcorn and watch a movie. But I hope that you take this knowledge and this understanding into whichever environment you are in. We need depth, density, and one thing I didn't mention is surface area. So more panels on the wall, more absorption. But really take a look around your room. I mean, there are some free tools that do require some equipment, called Room EQ wizard, and you can get a spectral analysis of your room to hear how your room is reacting to the sound and also how long it's taking for every frequency to decay. It's really, really fascinating. It requires very finely tuned microphones to do this. You cannot do it with your podcasting microphone. A very specific type of microphone, and I will be doing a video on that in the future. Oh my gosh, I'm so excited to get Roome EQ wizard in my room and really show what's going on in a room and why all these little nuances matter.


But for right now, know that reverberation is bad. It's not just something that would be nice to get rid of if you could. It is something that is extremely damaging to the intelligibility of your podcasts, so you can potentially lose listeners, or your listeners won't be as engaged as they could be because they're not capturing 100% of what you're saying, because they also have to do the mental processing of filtering out all these extraneous sounds in your show. It's really bad for editing, for getting a good edit on your signal. It's really bad for mixing when you get those room modes that are in an audible audible frequency in relation to podcasting, and those one inch foam panels, the bed sheets on your wall, the one or two pillows behind your microphone are not helping, and can in fact be making matters worse.


So check out the show notes for this episode, cleancutaudio.com/episode/6 to find some more resources on room absorption. I can't possibly do it all in one day, but there'll be some cool links for you to check out there and discover more about how to make your room sound great so that your podcast can then sound great.


That's it for this week. Thank you all so much for being here. Make sure you're subscribed to the show, and if you are not already subscribed to the YouTube channel, make sure to go to youtube.cleancutaudio.com and check that out and I will see you all soon. Bye everyone.