Soundproof Your Studio

Wilson Harwood

I teach you how to build a soundproof studio. Even if you know nothing about soundproofing or construction I go in depth to turn you from a total beginner into a soundproofing master.

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231 episodes
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Episodes231

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Aug 7, 2023 · 23 min
Why Room Ratios Don't Work...most of the time
Free Acoustic Treatment Guide - www.soundproofyourstudio.com/acoustic If you are reading this, you may be facing some room ratio madness yourself. If you are trying to find the perfect room ratio, reading obsessively about room modes and genuinely feel like you have gone down a rabbit hole then you are in the right place. In this article I will ease your stress around room modes, and room ratios and hopefully send you back out in the world with a plan for your home recording studio. 1) Why Room Ratios Don't Work...most of the time Room ratios were created to give acoustic designers (aka you) the ability to design rooms with relatively small volumes that will still sound "good." I write good in quotes because we can never achieve a perfect room. Even the best room ratios will have flaws that need to be addressed. This said you may have jumped on a few room ratio calculators on the internet and found that with your ceiling height the room ratio given leads to a very small room. This is a common problem with using room ratios in basement, bedroom or garage home studio designs. We are always held back by our ceiling height because the ratio is based off of ceiling height to width to length and a low ceiling height means smaller length and widths to meet the ratio numbers. Meaning, if we can't raise up our ceiling height we can't get a big enough room to do our work in. Totally maddening...I know! So what is the solution. Well let me tell you, but first let's learn what makes a room "good" to begin with. 2) What Makes A Room Sound "Good" There has been a lot of research on what makes a room sound pleasing or good to the human ear. This is a subjective term and has been argued over the years by some of the world's top acousticians. One thing that makes a room sound good is having what is known as an even distribution of modes. (Now I am not going to get into what a room mode is in this article, but if you don't know, take a break and google it real quick.) Okay great, so an even distribution of modes means that modes are spaced evenly through each 1/3 octave frequency band. The human ear perceives sound based on a logarithmic scale and acousticians have plotted frequencies based on this scale. The key here is to know how to read it, not try to fully comprehend the science. Next, another thing that makes a room sound "good" is to never have modes fall on top of each other. This means two different types of modes (axial, tangential, oblique) line up at exactly the same frequency thus causing that frequency to ring out more in your room making your room sound "bad." To do this I am going to show you a really good room ratio and a very very bad room ratio. This will help you see what an even distribution of modes looks like and what the lining up or coincidence of modes looks like. 3) Arguably, The Best Room Ratio Arguably, one of the best room ratios is Sepmeyer's first ratio of 1: 1.14 : 1.39. Now, we will see in a moment how best can be misleading, but stick with me here. The image below is from the AMROC room mode calculator. It shows Sepmeyer's first ratio with a ceiling height of 15 feet. Now we don't really need to look at anything above 125 Hz. The reason is that we can easily treat those frequencies with velocity based acoustic panels. What is harder to treat are room modes below 125 Hz. Now what we notice first is that in the lower frequencies we have a relatively even spacing of room modes. That is good! In a second you will see what big gaps will look like. We also want to look at the Bonello chart. It shows a smooth increase in modes per 1/3 octave. That is also considered "good." If that number goes up then drops down, then your room will not sound as good. 3) Size Matters! I know I hate seeing that statement too, but in room acoustics the volume of our room also matters. You could use that awesome Sepmeyer ratio, but if you have an 8 foot ceiling it will not sound as good. Let me show you why. Below is another screen shot from the same Sepmeyer ratio we used on the 15 foot tall room. However, this chart shows the room modes for an 8 foot tall room. At first glance they look the same, right? But wait! The relative distribution, meaning the spacing between the modes is the same, but where the modes fall on the musical scale has changed. In a smaller room those same modes have been shifted up in the low end. This means we have more problem modes in our audible bass frequencies than we did with the larger room. Notice how the first mode in our 15 foot room started well below 30Hz - barely in the audible spectrum of hearing, while that same mode falls at 50Hz in our 8 foot room, right in the middle of your kick drums thump! This is why bigger rooms meaning taller ceilings are better for music spaces. Because the problem modes get shifted lower and lower. This means treating our room becomes easier and less expensive because we have less low modal issues we need to smooth out. 4) A Truly Crappy Room Ratio The worst room you could possibly build is a cube. If the dimensions are 1:1:1 then your room will sound bad. Your room will also sound bad if you use even multiples like 1:2:3. So for the sake of learning how to read the AMROC calculator let's now look at that dreadful cube room. Gross! I mean that is just repulsive looking. Okay I kid, but yes this room will definitely sound bad and will be difficult to acoustically treat. Why? Well, first we have large gaps between those modes in the low end. Notice how our 8 foot tall room above has more lines in the low frequencies. Well, that is a good thing and we want them spaced evenly. Next, the Bonello criterion shows that we have a drop in modes from 3 to 1 and then a huge jump to 12. Considering ideally we want those numbers slowly increasing or at least staying the same, this is also a problem. Lastly, we didn't talk about this yet, but notice how there are a lot of bunched up lines that are red, blue and purple in the Sepmeyer rooms? Notice also how they start bunching together at lower frequencies than the cube? The bunching of lines is what we want. That actually makes the room sound more smooth and even. The big gaps make the room sound wonky because certain notes are louder than others or they may disappear completely depending where you stand in the room. Ideally, our low end would have a ton of lines too, but we just can't get that due to physics. Bummer I know! So, a good room will have those bunched lines start clumping together as low as possible. This is known as the Schroeder Frequency. That is just a fancy term that states when your sound waves stops behaving like waves and act more like rays. We want the sound in your room to behave like a ray at as low a frequency as possible because it is easier to treat with velocity acoustic panels. So, all you need to know is that the lower the Schroeder Frequency the better. Simple! Okay, sorry if I lost you there, but all you need to know is: bunching together good. Bunching together at lower frequencies good. The more bunching the better and bunching evenly is the best! Yay! Lastly, in our cube room several of the modes in the low end happen at the same frequency. Remember these are bad and will mean certain notes in your room will ring out more leading to an uneven listening and recording environment. Ahhhh but, Wilson, I am still reading and you have not offered me a solution yet. I know, but I need to teach you how to read the calculator so you can move beyond the room ratios. More on that in a second. 5) What About That Pesky Bolt Area? You may have noticed a little box labeled Bolt Area in the bottom right of the diagrams I have shown you. You may also have noticed that none of the rooms I have shown you fall in the bolt area. First, The Bolt Area was a diagram created by Bolt (acoustician dude) who wanted to make it easy to find good room ratios. Before computers you could look at his graph and pick some room ratios that fit your design and would just hope that the room modes were evenly spaced. The problem is that people have found many room ratios in the bolt area that really are not so great. This lead to other graphs being created. Here is a super handy tool you can use to dive deeper on room ratio graphs. This link - https://www.acoustic.ua/forms/rr.en.html The link above will show you where your room ratio falls according to the Bolt Area, The European Broadcasting Recommendations and the IEC Recommendations for room ratios. On top of that the acoustician Trevor Cox did an analysis of rooms and found out some more cool stuff. He says that if your room falls in the gray or black area of the graph then you will have a nice room. If it falls in the white area then things will go south for you. Dang! Notice that the calculator has a drop down menu for "room cubing." Make sure to set that number to your rooms volume. So for our situation it should be at 100 cubic meters not 50. Let's take a look at our 15 foot Sepmeyer room on this calculator. Now it's hard to see, but I think we fall on a grey area. However, we really don't fall within any of the other recommended areas. You can see how this is all maddening. Remember, these calculators are meant as tools and a guide. The best room for you will be one that has as smooth a mode spacing as possible, has a slowly rising mode count per 1/3 octave band, and most importantly is big enough for you to do the work you need to do in there. Conclusion - So What Now? I have just taught you how to read these calculators and diagrams. What I propose you do is put in your ideal dimensions and adjust those dimensions slightly to try and get your room to meet the criteria I mentioned. Stay away from 1:1:1 and 1:2:3 ratios. Another little trick if you have bad dimensions, say 8x8x8, is to increase and decrease two dimensions by 5%. So you could decrease the width by 5% and increase the length by 5% and your room would be much better. (Myth: Modes and Room Ratios: “I Have Too Many Modes! I Need a Better Ratio to Get Rid of Them” - Soundman2020 - Studio Design Forum) If you can raise your ceiling height do it. If you are building from scratch choose the first Sepmeyer ratio and move on. Or you could look at Louden, but don't get too hung up on it. If you use a room ratio you are light years ahead of most home studios. You could also choose to plot a room on the dark area of the Cox calculator. Then you could check it on AMROC and see how the mode separation looks in the low end. Then you could make sure it meets Bonello's Criterion. The goal is to do the best you can with what you have and not lose sleep over it. There is no perfect room. I repeat, there is no perfect room. Your design must use these tools and still meet your needs. My advice is to pick a room size as best as you can and move on. Don't waste weeks and weeks calculating room sizes. In the end you will still need acoustic treatment no matter what. One last thing...don't build a cube. Works Cited Room Sizes Compliance With International Standards and Recommendations. www.acoustic.ua/forms/rr.en.html. “Amroc - THE Room Mode Calculator.” Mag. Andreas Melcher, amcoustics.com/tools/amroc. Myth: Modes and Room Ratios: “I Have Too Many Modes! I Need a Better Ratio to Get Rid of Them” - Soundman2020 - Studio Design Forum. digistar.cl/Forum/viewtopic.php?t=557. Everest, Frederick A., and Ken C. Pohlmann. “Modal Resonances.” Master Handbook of Acoustics, McGraw-Hill, New York, 2015.
Jul 31, 2023 · 10 min
Pressure Vs. Velocity Acoustic Absorbers
Free Acoustic Treatment Guide - https://www.soundproofyourstudio.com/acoustic When acoustically treating a room we have two major forms of acoustic treatment. The first method is using velocity absorbers and the second method is using pressure absorbers. To fully treat and balance a room we need to use both tools for two different purposes. In this article I will go over what each absorber is and how to use them. 1) Velocity Absorbers Velocity absorbers are what you most likely think of when you think of acoustic panels. They use insulation and an air gap to absorb sound waves and reduce reflections back in your room. Velocity absorbers also include foam panels which absorb sound through transfer to heat much like fiberglass insulation. 2) How Are Velocity Absorbers Used Velocity absorbers are great and affordable for treating your room, however they do have limitations. They are great at absorbing higher frequencies above 125Hz, but do very little at absorbing frequencies below 125Hz. The key attribute all velocity absorbers have is a porous composition. The air space within the material is what turns sound energy into heat because the fibers vibrate and create frictional resistance, which is then transferred to heat energy (Everest, Pohlmann 191). 3) Effect Of Thickness With Porous Velocity Absorbers According to The Master Handbook of Acoustics, "there is little difference above 500Hz as thickness is increased (Everest, Pohlmann 195). However, there is "considerable improvement below 500 Hz as thickness is increased" (Everest, Pohlmann 195). A four inch thick fiberglass panel of 3-lb/ft3 density has nearly perfect absorption over the 125-4k Hz region (Everest, Pohlmann 195). 4) Effect Of Airspace Behind Porous Acoustic Panels Adding a three inch airspace behind panels will increase its absorption. It is a best practice to leave an air gap between the fiberglass and your wall. In general the farther the panel is placed from the wall the lower frequencies it should absorb. As a general rule with velocity based traps a panel placed a 1/4 wavelength from the wall is where absorption is greatest (Everest, Pohlmann 195). For example, if we estimate the speed of sound to be 1,125 ft/second in our room then a 100 hz wavelength = 11.25ft (1,125 ft/sec / 100 Hz). A quarter wavelength of 100 Hz is then 11.25/4= 2.8125 feet. This would mean your velocity panel would need to have a nearly three foot air gap behind it to maximally absorb 100 Hz. Now most people cannot give up 3 feet on all their walls and ceilings to absorb down to 100 Hz. This is where pressure traps come in. However, before I dive into pressure traps. It is important to realize that velocity traps, although not efficient at absorbing sound below 100 Hz still absorb some in that area. This is very important because our goal as acoustic designers is to get the room as good as possible with velocity based absorbers as we can and then move to pressure based traps to sniper out some of the low frequency problems in our room. 5) What Are Pressure Based Absorbers? Pressure based absorbers also known as resonant or reactive absorbers use a different method than velocity absorbers to absorb sound. There are two main types of pressure absorbers: Panel or Diaphragmatic absorbers and Helmholtz Resonators. These two types of tools can pinpoint problem frequencies in your room below 125 Hz where our 4" thick velocity traps are not as efficient. Notice that I said pin point. The down side to pressure traps is that they have a narrow frequency band that they absorb. They can be tuned to attenuate specific problem frequencies in your room. For this reason, I always recommend that designers begin by treating their room with plenty of porous absorbers before going down the path of using pressure traps. Pressure traps are great at reducing room mode issues. Every room will have low frequency resonances that can muddy how we hear the bass in our room from what is actually coming out of our monitor speakers. In order to fix these low bass mud issues we can target a specific room mode issue with a tuned trap. 6) Panel (Diaphragmatic) Absorbers Panel traps are great at absorbing lower frequencies. They are essentially a wooden sealed box with a layer of fiberglass inside. The mass of the panel and the air spring created will absorb sound as the material is flexed and vibrates. There is additional absorption through damping by the insulation (Everest, Pohlmann 195). Another form of panel absorption are Polycylindrical absorbers, which work the same as a flat panel absorber, but have the added benefit of creating a diffuse sound field because of their semi cylindrical bulkheads. 7) Helmholtz Resonators Helmholtz resonators are cylindrical tubes much like a bottle. They absorb sound by using the air in the cavity as a spring that creates a resonant system. Just like blowing across the top of a bottle produces a resonant tone, helmholtz resonators also have a resonant tone and absorption is maximal at that resonant frequency. Helmholtz resonators can be tuned to target specific problem frequencies in your room. I will say, in my research many people have warned that Helmholtz resonators are not easy to make and small errors in construction can render them useless. 8) Conclusion Acoustically treating a room is like an onion. You start on the outside and get good results and gradually work your way towards the center getting more precise and more complicated as you go. For most DIY studios using velocity based traps will go a tremendously long way towards fixing your room issues. I also love room eq software like Sonarworks Sound ID to correct your speakers to fix issues in the low end. This can help mitigate problems when you are mixing or mastering. However, once you get your room dialed in as best as you can with velocity porous absorbers, next you will need pressure traps to reach those lower problematic room modes. To find your room modes you will need to test your room using a measurement mic and software like Room EQ Wizard. This will tell you what is wrong at your listening position and what room modes are ringing out at your listening position. From there you can build pressure traps to target those specific problem frequencies. Works Cited Everest, Frederick A., and Ken C. Pohlmann. “Absorption.” Master Handbook of Acoustics, McGraw-Hill, New York, 2015.
Jul 24, 2023 · 11 min
Should You Use HushFrame Rafts To Soundproof?
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop A member of our soundproofing community recently asked me about a product called HushFrame Rafts. I had never heard of them before so I did some research. In this article I am going over the benefit of using HushFrame Rafts, the cost comparison to other similar products and what they are. 1) What Are HushFrame Rafts I am usually very skeptical about soundproofing products. These Hushframe rafts are interesting though. They are a wood isolator used to decouple drywall from walls and ceilings using hat channels or wood channels. One of the biggest benefits to Hushfram rafts is that you can use wood as a furring channel not just metal, and you can save some space when using the Hushframe Rafts. According to their website, HushFrame rafts use Vi-Bridge Technology to reduce noise transfer through the clip into your drywall. Now that sounds like some fancy naming for a patented technology. That is okay as long as it works. According to their website they can achieve 80% noise reduction, and an STC of 66. However, we don't know what 80% noise reduction really means, especially for bass frequencies and we don't know how the wall was built to achieve an STC of 66. All this said, I would trust that these clips do in fact decouple drywall when installed correctly. So next let's look at another comparable product. 2) How Do HushFrame Rafts Compare To Other Iso-Clips Now the biggest difference in HushFrame Clips versus the IB-1 Iso Clips I used in my studio are price and the total depth of the clip. First, let's take a look at price. HushFrame Rafts are available at the ISOSTORE online for $4.95/clip. The iso-clips I recommend I found for $1.79 at Buildcorpdirect.com. The first important factor is to look at price. The A237 Resilimount Clip is $3.16 cheaper than the HushFrame Rafts. This could add up depending on how many clips you need. Most studios will need dozens of clips, so cost could be a factor. Second we want to look at the amount of space each clip adds to the wall assembly. The Hushframe Raft as you can see below uses up to 1" of space if using 3/4" wood furring or 1 1/8" if using 7/8" furring channel. Source Image: HushFrame Website Now if you are using the IB-1 or A237 Clip (they are the same with different names) then you will have a 7/8" furring channel sitting in the clip with a few 16ths of an inch below the furring channel. I am not 100% certain on that exact height but it should be around 1" to maybe 1" 1/8". Either way, I believe the space saved using the HushFrame Raft is pretty minimal. Below is a diagram of the A237 Clip: Now let's look at a diagram from the Soundproofing Company Website that shows different STC ratings using the IB-1 iso clips and 7/8" furring channel. You can see that if you use Green Glue between the layers and two layers of drywall with Green Glue on the backside you get an STC of 71. With one layer of drywall on one side and the hat channel system on the other side with Green Glue you get an STC of 67. If you use two layers of drywall without Green Glue you get an STC of 58. Those are all better than the HushFrame Rafts accept the STC of 58. However, remember we really don't know what wall system they were referring to. If you added another layer of drywall to the outside of the wall it would increase the STC regardless of your iso clip. 3) Conclusion Would I use the HushFrame Rafts in a soundproof studio build? Probably not because I can get the same STC rating using a cheaper clip and the space saved is pretty negligible. The only time I might recommend the use of Hushframe Rafts is to create a decoupled vent through your wall. I could see how using the rafts to build a custom ventilation system could be useful, but other than that I would stick with the cheaper clips and put your money on more drywall and Green Glue.
Jul 17, 2023 · 10 min
What Are Noise Criteria Levels?
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop When designing a soundproof room, acoustic designers will use Noise Criterion Curves or NC curves for short to ensure the room meets proper sound isolation guidelines. In this article I will go over what NC curves are and how to use them as a guide for your own studio build. 1) What are NC Levels Noise Criteria levels are benchmarks we can use to get our soundproof rooms to an industry standard. Here are some guidelines for NC Levels for various applications: NC 15-20: Broadcasting Studios, Concert Halls, Recording Studios and Music Rooms NC 30: Residences, Theaters, Libraries, Executive Offices NC 35: Private Offices, Schools, Hotel Rooms, Churches, Hospitals NC 40: Labs, Dining Rooms, General Office Use NC 45: Retail Stores, Lobby Areas, Reception Areas NC 50+: Computer Rooms, Print Machine Rooms Studio designer and soundproofing expert, Rod Gervais states that his goal when designing professional recording studios is to shoot for NC 20 or below and preferably NC 15 if possible. (Gervais 158) Each of these NC levels represents acceptable sound pressure levels at eight octave band center frequencies. Below is a diagram from Home Recording Studio: Build It Like The Pros by Rod Gervais. Notice for a studio to fall in the NC15 range you must get 47 dB at 63Hz, 36dB or below at 125Hz and so on. Now that you understand the concepts behind NC levels you might be wondering how to calculate these levels in your own home studio. 2) How To Calculate NC Levels NC levels are not easy to calculate without the right tools and experience. For this reason I recommend using the chart above as a guide and using your smart phone to record levels. Although, this is not a great method for professionals for the average DIY studio build getting some general ideas of how much isolation you need is helpful. I recommend using the DecibelX app. You can download it for free and can pay for an upgrade if you want. This app allows you to measure the average dB level in your room and you can see the dB range over the frequency spectrum. This will help you see where you may have potential problems in your soundproofing design. If you want a professional level test done then you will either need to hire someone with the right experience running NC level tests or rent the right gear and read the guidelines. The American National Standards Institute (ANSI) provides guidelines for getting accurate measurements. You can look those up at ANSI S1.13-1971 (R 1986) American National Standard Methods for the Measurement of Sound Pressure Levels (Everest Pohlmann 313). If you do your own measurements you will need to calibrate your SPL meter. You will also need a meter that can measure octave band frequencies and it should be mounted on a tripod for accurate results. As you can see, there is a reason professionals do this work. It must meet stringent standards to qualify as credible data. The choice is up to you if you want to try measuring NC level at all. I find the knowledge useful in understanding benchmarks for professional studio design, but probably overkill for the average DIY home studio build. Works Cited Everest, Frederick A., and Ken C. Pohlmann. “Modal Resonances.” Master Handbook of Acoustics, McGraw-Hill, New York, 2015. Gervais, Rod. Home Recording Studio: Build It Like The Pros. 2nd Edition, Course Technology Cengage Learning, 2011.
Jul 10, 2023 · 13 min
Soundproofing Your Home Studio 101
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop This week things are a little different. This video is actually the visual part of a blog article I wrote for the Sonicscoop blog. If you have not heard of Sonicscoop they are a great resources for all things home recording related. You can read the full blog article at - https://sonicscoop.com/soundproofing-your-home-studio-101/ 0:00 - Intro 1:44 - Soundproofing vs Acoustic Treatment 3:12 - The Three Pillars Of Soundproofing 5:36 - The Best Soundproof Floor 6:37 - The Best Soundproof Wall 8:14 - The Best Soundproof Ceiling 9:00 - The Importance of Fresh Air 10:07 - Soundproof Doors and Windows 12:46 - Conclusion
Jul 3, 2023 · 15 min
What Is The Ideal Ceiling Height For A Recording Studio?
FREE Acoustic Treatment Guide: https://www.soundproofyourstudio.com/acoustic You may have visited some professional recording studios and noticed that the rooms had high ceilings, especially the tracking room. Now in your home studio do you need a high ceiling? In this article I will talk about why higher ceilings are beneficial and some of the room acoustic theory behind recording studio room design. 1) High Ceilings Are Great For Drum Recording A very basic, but important reason large pro studios have high ceilings in the tracking room is to give the wave forms enough space to develop before hitting a surface and reflecting back to the microphones and your ears. This is especially true when recording drums or large ensembles like an orchestra. In most home studios an 8 foot ceiling barely gives you enough height to place the overhead mics. You will mostly pick up the cymbals in a lower studio and the reflections from the ceiling will create a "harsh" tone. This is a very practical reason for having larger ceilings, but what about the physics of room acoustics? How do room acoustics improve with higher ceilings? 2) Room Modes To really grasp why higher ceilings are beneficial in a room, we must first understand some basic room acoustic physics. All rooms create reflections where sound waves bounce off of. When sound emanates from a source, say a speaker, the air in the room is excited by the sound waves. The sound travels in all directions from the speaker and bounces of the walls, ceiling and floor. When the sound bounces off the surfaces it then returns back into the room. The reflected waves then encounter new sound waves coming from the speaker and they interact with each other. The sound waves either create a boost because of constructive interference or they create a null known as destructive interference. These peaks and nulls in the sound waves create acoustic distortions. Now, there is a slight difference in how higher frequency sounds behave versus lower frequency sounds. Sound waves above 250Hz perform more like a "ray." Meaning they travel in a direct line and don't have as much energy as sound waves below 250Hz. Sound waves below 250Hz and especially below 100Hz have much more energy and have much longer wavelengths. These sound waves create what we call room modes. These room modes or are areas of high or low pressure due to those sound waves running into themselves after bouncing off your rooms surfaces. Okay, that was a bit complicated, but it is very important to understanding why high ceilings are important. The reason is that we ultimately want larger rooms to allow for enough space for those low frequency waves to fully form or at least form as much as they can before hitting a surface. Depending on the distance the waves travel from a source (speaker) and a surface (ceiling) the room modes will change. 3) Room Ratios This brings us to the next point about ceiling height. The ceiling is only one part of the room. We must also consider the length and width of our room when designing a recording studio. Over the years some acousticians have come up with room ratios that create a pleasing acoustic environment for sound reproduction. These room ratios should be considered a starting point and are by no means the end all be all of acoustic design. You may be wondering as I did why we don't know the way to design the perfect room for a recording studio. After all, if we can measure room modes and use room ratios to reduce them why not build the perfect mathematically correct studio? The answer is that, acoustics is as much an art as it is a science. Just because one room sounds good to one person does not mean it will sound good to another. In fact, the way we perceive sound is uniquely human. We do not hear everything the way the math works out in physics. We hear how our ears and brain perceive sound in a room. This makes the job of designing your studio that much less precise, but also gives you the freedom to design a room that is pleasing and does the job you need it to. All this said, we can use room ratios to get us in the ballpark with a room that will have less acoustic problems and thus cost less to acoustically treat in the long run. Some common room ratios are from the acousticians, Sepmeyer, Louden, Volkman and Boner. Below is a diagram of some of their room ratios. 4) The Problem With Small Rooms Now you can use these ratios, but you are not guaranteed great results if your room is still small. The reason is that if your rooms dimensions are comparable to the wavelengths of audible sound then may have problems with "excessive separation between modes." (Everest,Pohlmann 261) The large separation between modes leads to unpleasant acoustic distortion in your room. To get uniform spacing between room modes and avoid coincidences (where modes pile up on top of eachother) you need more room volume. This means larger rooms are generally thought of as sounding better and are preferred for tracking rooms and control rooms. However, in control rooms the reverb time must be lower and all reflections must be treated to create a flat listening response. 5) Conclusion It is very important to remember that "there is no ideal ratio of dimensions" for a room. (Everest,Pohlmann 256). As studio designers we can only create a good starting point and then measure and analyze the room once it is built. For most of you reading this, I would assume you are working with rooms you already have or may be able to build a studio in your backyard. Either way it is important to remember that the larger the volume the better your room will sound and if you use room ratios you will have a better starting point. In a basement studio this could mean building a wall in the existing basement to create an ideal room ratio. In a studio build in a backyard it could mean building a larger studio to help with even distribution of room modes and avoiding coincidences. To answer our original question. The ideal ceiling height is probably the tallest ceiling you can afford while making sure it fits within a good room ratio for the least acoustic distortions caused by room modes. In the end don't lose sleep over this, but know that understanding room modes is an important aspect of getting your room to sound as good as it can from the start. Works Cites: Everest, Frederick A., and Ken C. Pohlmann. “Modal Resonances.” Master Handbook of Acoustics, McGraw-Hill, New York, 2015.
Jun 26, 2023 · 5 min
How Loud Is My Mr Cool Mini Split?
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop In this podcast I am using my Decibel X app on my phone to record the decibel levels at various spots in my studio while the mini split is on, off and in silent mode. The goal of this video is to give you some solid numbers and video audio to base off your decision to purchase a Mr. Cool Mini Split. In my experience the mini split is plenty quiete for recording vocals, acoustic guitar and other softer instruments. I also give you a bonus set of videos showing how loud my ventilation system is. In the end I still recommend the Mr. Cool Mini Split in most studio builds because it works and is affordable. Yes, a ducted mini split would be quieter, but would also cost several thousand dollars more.
Jun 19, 2023 · 12 min
Where To Buy Soundproofing Supplies In Europe
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop Many Europeans in our community have commented that it is hard to source the right materials in Europe. In this article I will share some resources that I recommend for our European friends. 1) What materials do you really need? If you go to most soundproofing store websites they will have dozens of soundproofing supplies. The truth is you don't need much if you are building a soundproof room. Most of the stuff they sell is not really necessary, but does make them money. Here are the supplies you definitely will need: Acoustic Sealant (Caulk) Putty Pads Door Seals Here are the supplies that you might need: Green Glue Isolation Clips Hat Channels (Furring Channels) MLV Wall Sway Bracing Clips (For Double Wall Designs) Everything else you see on their websites, in my opinion, is not needed for soundproofing a room. Pretty easy right? So in my reviews of these different online stores these were the materials I was looking for. 2) Noise STOP Systems Noise Stop Systems is based out of the UK. They supply: Acoustic Iso Clips Hat Channels Acoustic Sealant Acoustic Putty They do not have any door seals. I would recommend them as a possible choice for your soundproof supplier. 3) The Soundproofing Store They are another UK store. They supply: Reducto Clip Hat Channels Acoustic Sealant Door Bottom Seals Acoustic Putty Pads If you need to get door bottom seals I would recommend this store. They are a good option since you can get pretty much everything you need from them. 4) Acoustic Block This is, you guessed it, another UK based soundproofing company. They supply: Acoustic Sealant Putty Pads I would only go with this store if the price is right. They don't have what most people will need. 5) Soundproof Cow Now this is an American company, but they do ship internationally. However, you must call them for international orders. They supply: Green Glue Acoustic Clips Angled Acoustic Clips (for double wall assemblies) Door Seals and Sweeps 6) Mason Industries When it comes to soundproofing products Mason Industries is the highest quality. I recommend their WIC isolation clip or DNSB clip for heavier wall and door assemblies. These clips are excellent choices as a sway brace for your double wall assembly. They have dealers in Europe where you can buy their products. The main takeaway is to remember that most soundproofing stores what to sell you stuff. They can't make money off of telling you the best way to soundproof just the way that uses their materials. Be wary of any supplier saying you need a ton of materials when you know you don't.
Jun 12, 2023 · 15 min
Should You Buy A Whisper Room Vocal Booth?
Free Soundproofing Budget Calculator: https://www.soundproofyourstudio.com/calculator I recently had someone in our community reach out about the Whisper Room Vocal Booth. I was curious to do a review and see if I could help them and you with some advice on is the Whisper Room Vocal Booth a good choice for your studio. 1) What Is The Whisper Room Vocal Booth? Let's start with an overview of what this booth is and how it is made. They come in two models for isolation needed. They have a single wall model and a double wall model. The double wall model will provide more isolation and should be used for loud bands or drummers and perhaps a producer with speakers and a subwoofer. The coolest part of these booths is that they can be installed quickly and moved to different rooms over time. A soundproof construction job is permanent and cannot be moved. Each Whisper Room booth comes with a door with a window and the option for ventilation. It also comes with some 2" thick Auralex foam panels to control reflections in your booth. 2) How Well Does It Soundproof? This is the number one question and the answer is okay depending on your needs. They say on their website that their booths are not completely soundproof, but do provide "outstanding sound isolation." This is true of all soundproof rooms. The question is how well do the isolate across the frequency spectrum. On their website they have a cool calculator to estimate the transmission loss (drop in decibels) at certain frequencies. The frequencies they measure for are 125hz-4000hz. This frequency range is the common range for the human voice, but it does not account for bass frequencies from speakers, bass guitar, and kickdrums that will easily reach below 100hz. For those low frequencies we don't really know how well the Whisper Room will perform. I recommend you play around with calculator. The important thing is to measure your room with a decibel meter app on your phone and learn what the general noise floor is in your room. For most homes this will probably be in the range of 40-70dB. You want to isolate for the loudest sounds. A good recording studio will have a noise floor of 30dB or less across the frequency spectrum. For purposes of this article let's say our loudest noises in our room are around 70dB. This is the sound of a vacuum cleaner. The Whisper Room calculator says you would get the following. We can see that with the standard wall you get 27dB of reduction at 4k Hz which would mean your noise floor in the booth would be 43dB instead of 70dB at 4k. At 125Hz your noise floor in the booth would be 49dB. For reference a 10dB change is perceived as either a doubling or halving of loudness to the human ear. Now to put 43dB-49dB in perspective that is somewhere in the range of a library on the low end and a conversation in a home at the high end according to their website. Now if someone is vacuuming right next to your booth you most likely will not want to record. However, these booths probably are great for reducing isolation in an already fairly quiet environment like the inside of a control room, a TV studio or a house basement on a fairly quiet street. I don't think these booths would work well for drums, bass amps, or a studio with speakers that can easily reach below 125Hz. Lastly, they don't offer any STC ratings, which make it hard to compare to other soundproof assemblies. 3) How Much Does It Cost? This is the next logical question. They are not cheap, but neither is soundproofing a room. The Voice Over Deluxe Package is a 4ftx4ft booth with double walls and ventilation included and it costs $11,118.80. That does not include shipping or tax. To compare the cost of building your own vocal booth I am going to use my Soundproof Budget Calculator. To get the better isolation that their booths and build your own 4ft by 4ft booth I estimate is would cost $3,454.80. That is a difference of $7,664. Now, you are paying for convenience, you don't need to know how to build a soundproof booth, and you can have it delivered right to your doorstep. There is something to be said for how easy that is, but is it worth the extra seven thousand dollars? That is up to you to decide. 4) Do I Recommend You Buy A Whisper Booth For most people, no, I would not recommend you buy a Whisper Booth. The ideal person who should get a whisper booth will have a large budget, not want to do any construction or deal with any design planning, only need the booth for voice over work and ideally live in a fairly quite house already. If you are in a busy office, on a super loud street or needing to isolate against lower frequencies then I don't think the Whisper Booth will do the trick. I think the Whisper Booth is a solid product with decades of experience, but it is a premium price on something many of you could do DIY and get potentially better results. Lastly, I think another downside to the booth is how it looks. If you don't like the look of their product then you don't really have a choice. If you build your own booth then you get the freedom to design it exactly how you want it.
Jun 5, 2023 · 11 min
Is Your Soundproof Studio A Health Hazard?
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop If you don't build your soundproof studio correctly you may be introducing some health hazards into your space. In this article I will discuss three common issues with a soundproof room that many DIY builders forget to do that can lead to headaches, fatigue, fire risk, and mold sickness. 1) Firestops When I work with my soundproofing clients I often find that they have not thought about fire stops. Fire stops are an important part of a soundproof room built using the double wall design. Without fire stops your double wall system acts like a chimney. A fire could start in the walls and expand up into the ceiling within seconds without anyone in the room even knowing there was a fire. The fire could then jump to other rooms in the house or building very quickly. To prevent this from happening we install firestops at the top of the double wall assembly to block the smoke and flames from entering other parts of your structure. The diagram below shows a typical firestop design. Notice how the compressed rockwool and fire caulk create a sound barrier from the wood stud and 1/2" drywall. The drywall sits across both studs and seals the 1" air cavity between your two walls. When done properly a firestop will prevent flames from moving into your ceiling. 2) Ventilation When you build an airtight room you must ventilate it with fresh air. To properly soundproof a room it must be airtight. This means that fresh air from outside the room does not enter into your soundproof structure. Mini Splits and home HVAC units do not provide fresh air unless you install a fresh air intake system. When building your soundproof studio it is very important to install some sort of ventilation system to provide fresh air (ideally from the outside) to your soundproof room. The reason we need fresh air in an airtight room is that there is a build up of C02 that accumulates in soundproof rooms. When we exhale we breathe out C02 and the build up of C02 has been shown to cause: headaches, dizziness, restlessness, a tingling pins and needles feeling, difficulty breathing, sweating, tiredness, increased heart rate, elevated blood pressure, coma, asphyxia, and convulsions. (Wisconsin Department of Health Services) Now, the amount of C02 directly impacts the health risk. In most soundproof rooms you would need to go to the bathroom before it became deadly. However, the fatigue, headaches and drowsiness are a real issue at much lower levels. Let's take a look at these numbers from the Wisconsin Department of Health Website: The levels of CO2 in the air and potential health problems are: 400 ppm: average outdoor air level. 400–1,000 ppm: typical level found in occupied spaces with good air exchange. 1,000–2,000 ppm: level associated with complaints of drowsiness and poor air. 2,000–5,000 ppm: level associated with headaches, sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present. 5,000 ppm: this indicates unusual air conditions where high levels of other gases could also be present. Toxicity or oxygen deprivation could occur. This is the permissible exposure limit for daily workplace exposures. 40,000 ppm: this level is immediately harmful due to oxygen deprivation. (Wisconsin Department of Health Services) In my studio I have a CO2 reader. When I first built my studio the levels would easily reach into the 1,000-2,000 ppm range when it was just me in the studio. When we had 3-4 people in there for a couple hours levels would reach around 2,000-5,000 ppm. This is all to say that you don't want stagnant stale air in your studio that leads to headaches, sleepiness and poor concentration. 3) Humidity Lastly, an often overlooked concern is mold growth from high humidity levels. According to the North Carolina Department of Health and Human Services: mold will almost certainly grow if relative humidity stays at 70% or higher for extended periods of time (NC Department of Health and Human Services). According to Rod Gervais in his book Home Recording Studio: Build It Like the Pros, ideal relative humidity levels for comfort and your musical instruments should be in the range of 30-50% with 45% being ideal relative humidity (Gervais 136). When designing your soundproof studio it is important to think about how you can mitigate mold growth. The first way is to properly size your HVAC or mini split unit. An oversized unit runs on shorter cycles making it less efficient at pulling excess moisture out of the air. This will lead to high RH in your studio and home. The second way to remove excess water vapor in your room is to install a dehumidifier. I have a dehumidifier in my studio and it works great, but it is loud. During sessions I have to turn it off. A better solution is to install your dehumidifier in a separate room and connect the rooms using a baffle box. This way fresh dehumidified air can enter your soundproof room without the noise of the unit. Conclusion When building a soundproof studio it is important to design for fire safety, healthy air and healthy levels of humidity. If you do not follow these guidelines then you run the risk of introducing serious fire risk, the potential for headaches and poor concentration as well as the risk for mold toxins in your studio. Now that you are aware of the risks make sure to design firestops, ventilation systems and humidity regulation in your studio. This way you will ensure you have a comfortable, safe and healthy environment to create music in. Works Cited: “Carbon Dioxide.” Wisconsin Department of Health Services, 29 Mar. 2023, www.dhs.wisconsin.gov/chemical/carbondioxide.htm#:~:text=Exposure%20to%20CO2%20can,coma%2C%20asphyxia%2C%20and%20convulsions. Public Health, Epidemiology. “Mold.” NC DPH: Occupational and Environmental Epidemiology: Conditions That Promote Mold Growth, epi.dph.ncdhhs.gov/oee/mold/conditions.html#:~:text=If%20there%20are%20no%20cold,mold%20will%20almost%20certainly%20grow. Accessed 29 May 2023. Gervais, Rod. Home Recording Studio: Build It Like The Pros. 2nd Edition, Course Technology Cengage Learning, 2011.
May 29, 2023 · 11 min
How To Properly Caulk A Soundproof Wall
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop Acoustic Caulk is a key material in soundproofing. It is used to seal all possible air gaps in your soundproof wall design. The internet is full of lots of ways to do this, but what is the best way for your soundproof wall? In this article, we will dive into how to properly caulk your soundproof wall assembly so that it is airtight and will not fail when you finish your soundproofing build. 1) Why Use Acoustic Caulk and Not Regular Caulk or Silicone? Let's start with why we use acoustic caulk in the first place. Regular caulk or silicone hardens when it drys and is prone to cracking. Acoustic caulk, on the other hand, remains flexible even once it has dried. This means the airtight seal you need will remain many years down the road. Using regular caulk to save money means you risk having small air leaks in your soundproof room that could lead to less isolation over time. 2) Which Acoustic Caulk Should You Buy? When it comes to soundproofing people have some very strong opinions. I used Green Glue's Noiseproofing Sealant (this is not Green Glue Noiseproofing Compound). I think it worked well. Now some other brands you can research are TMS Acoustic Caulk, Auralex Acoustics STOPGAP, and Tremco Acoustical Sealant. Don't lose sleep over which brand to choose. I might recommend the cheapest so you save some money. They all are acoustically rated and will do the job you need them to do. 3) Caulking Your Bottom Plate Now, there are a lot of different recommendations when it comes to caulking your wall. In my studio I did not caulk underneath the bottom plate and it was totally fine. However, according to the The Soundproofing Company and Everkem Diversified Products (sealant manufacturer) you should use three beads of acoustic caulk under your bottom plate, one under your first layer of drywall and one under your second layer of drywall. (The Soundproofing Company, Matt Everkemp Products). Below is a diagram from the Soundproofing Company Website that demonstrates this design. *From the Soundproofing Company Website Now, I used rigid sill plate gasketing, which is a fancy word for foam that protects your bottom sill plate from moisture and rot. This can help decouple a bit too although that is all theoretical and not lab tested. We could have added acoustic caulk under the sill plate gasketing to add an extra layer of air tight sealant, but I don't think it was necessary in my build. I build my studio on a single concrete slab and am not worried about noise coming up through the earth, the slab and into my studio. However, if you are worried about noise transfer through your floor or slab then I would add the extra acoustic caulk just for good measure. 4) Should You Leave A Gap Where The Wall and Floor Meet? This is a common question I see on the internet. In my opinion it depends. Again, in my studio I was not worried about resonances from my slab to my drywall, so we put the drywall right onto the slab and used acoustic caulk along the entire perimeter where the drywall meets the floor. I think this is totally fine in this scenario. However, if you are worried about flanking noise paths from the floor to your inside wall then I would employ a different method. To get maximum isolation from your floor flanking paths I recommend leaving a 1/4" to 3/8" (6-9mm) gap between the drywall layers and your floor. Put backer rod under the drywall to fill the gap and then seal it fully with acoustic caulk. This will help reduce vibrations from the floor to your inside wall and will ensure your gap is airtight. You should do this on your outer wall too. 5) Should You Leave A Gap In Your Corners The next question you might ask is, should my corner drywall panels touch. The answer, you guessed it, is it depends. In my studio I didn't worry about leaving a gap in my corners because the room is a standalone structure in my backyard. However, if you are worried about vibration from one wall that may have a lot of sound behind it transfering to other walls then creating a gap could help reduce the transfer of sound from wall to wall. To do this you should leave a 1/4" to 3/8" gap (6-9mm) between your first layer of drywall. Then add backer rod and acoustic caulk to the gap. Next, add your second layer of drywall and leave the same gap. Add backer rod and acoustic caulk to this gap as well. This will ensure the drywall is not touching and transferring sound, but that the gap is airtight and not letting sound through. 6) Should You Leave A Gap Where The Wall Meets The Ceiling? This is a good question too. If your ceiling is built off your inside wall and is what I call an "independently framed ceiling" then you do not need to leave a gap. The reason is that the frame your drywall is attached to is not connected to the roof or floor above. This means no sound will transfer. If however, you are using ceiling hangers or hat channels for your ceiling design then I think it is a good idea to leave a 1/4" to 3/8" gap (6-9mm) between your wall and ceiling drywall. Do the same design we did for the corners. Hang your first layer of drywall on your ceiling. Then put backer rod and acoustic caulk in the gap. Next, hang your second layer of drywall and put backer rod and acoustic caulk in the second gap as well. This will ensure that sound vibrations traveling from your wall will not connect to the ceiling and sound from the ceiling will not transfer to your walls. Below is a diagram from Home Recording Studio: Build It Like The Pros by Rod Gervais. (Gervais 264) Conclusion Caulking your perimeters and beneath your bottom plates is a good idea. If you are worried about flanking paths and noise traveling from your floor to your walls, your walls to your ceiling or your ceiling to your walls then you should leave a 1/4" to 3/8" gap (6-9mm) and fill it with backer rod and acoustic caulk. I hope this article helped clarify this confusing topic about properly caulking your soundproof walls. Works Cited: The Soundproofing Company. "Soundproof a wall: Best (Level 3)." The Soundproofing Company, 24 May 2023, https://www.soundproofingcompany.com/soundproofing-solutions/soundproof-walls/spc-solution-3-double-stud-wall. Matt. "SIMPLIFYING SOUND REDUCTION: FLANKING NOISE AND ACOUSTICAL SEALANTS." Everkem Diversified Products, 9 Oct. 2017, https://everkemproducts.com/sound-reduction-flanking-noise-acoustical-sealants/. Gervais, Rod. Home Recording Studio: Build It Like The Pros. 2nd Edition, Course Technology Cengage Learning, 2011.
May 22, 2023 · 12 min
Humidity Problems In Your Home Recording Studio
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop HVAC is certainly the hardest part of building a soundproof home recording studio. An often overlooked part of your heating and cooling system is humidity control. In this article we are going to go over the best practices when designing your HVAC system to keep your relative humidity in the ideal range. 1) What is the ideal relative humidity? This is a debatable topic, but most books I have read and websites I researched said that 30-50% relative humidity is ideal. (Lennox) 2) Why do we use the term "relative" when talking about humidity? You might be wondering why we use the term "relative" when talking about humidity. The reason is that humidity is the amount of moisture air can hold at any point in time. The amount of moisture air can hold is not constant. It is dependent on the temperature and air pressure. However, the amount of water in a room does not change with temperature and air pressure. For example, when you blow up a balloon you put both air and some water vapor from your mouth. Now if you put that balloon in the freezer the balloon will shrink because the air is colder, but the amount of water droplets in that ballon will not change. This is similar to how relative humidity works in your studio. 3) Where does humidity come from? So most humidity issues will come from people exhaling in your studio and fresh air being brought in from the outside. In the winter months your studio may be too dry and in the summer months your studio may be too wet depending on your climate. 4) How do you get the right humidity in your room? This is the main question and there are a couple answers depending on your HVAC system. First, let's learn about sensible cooling loads and latent cooling loads. Sensible cooling loads: measure the ability of your unit to cool the air in your studio. Latent cooling loads: measure the ability of your unit to remove moisture from the air. Now calculating those loads is best left up to an HVAC specialist or contractor with experience in HVAC installs. However, you still can ask if the latent cooling load with be adequate if you have an ERV pumping in X amount of air per minute and X amount of people in your studio. Some contractors will oversize units either to make more money or simply out of ignorance and this can cause problems with your latent cooling load. The reason is that a unit that is too big for your home or studio will run in short bursts. This starting and stopping of the system does not give the unit enough time for the coil to reach dew point and for the air to have enough time to cycle the room through complete air exchanges. (Gervais, 139). This means the air will not pass over that coil and drip into the drip pan removing moisture from the air unless the unit runs for a long enough time. All in all, it is important to communicate with your HVAC tech or even a couple different ones to get opinions on how big your unit should be to properly remove moisture from your house/studio and keep the relative humidity between 30-50% year round. 5) What about mini-splits? I am a big fan of mini-splits and energy recovery ventilators working together to heat, cool and provide fresh air in your studio without adding any unwanted noise. The downside to this system is the humidity control can be a bit tricky. Now, my Mr. Cool mini-split does have a "Dry" mode, which does help remove moisture from the air. In dry mode the unit will end up cooling your room a bit more to help control humidity. This can be great, but I have found that sometimes the room feels a bit too cold to get down to lower humidity levels. The ERV will bring in fresh air from the outside, but on super wet days here in Nashville that air is still fairly humid when it enters the studio. 6) Use a dehumidifier It might seem overly simplistic, but you can use a dehumidifier to help with any extra humidity problems you may be experiencing. Yes, these units might not be whisper quiet, but they can run at night or when you are not recording. You can also design your studio to have an air exchange room where the room next to the studio has a dehumidifier and air conditioner in it and the air is then sent into your studio room. This is not always possible, but it does allow for quiet in your studio at all times regardless of humidity issues. Conclusion Humidity can be an issue depending on your climate and time of year. The main goal is to keep relative humidity between 30-50% year round. Remember to properly size your HVAC unit to achieve proper latent cooling loads. If you need some extra help you can always run a dehumidifier when you are not recording to help remove moisture from the air. Works Cited Gervais, Rod. “Chapter 7: HVAC Design Concepts.” Home Recording Studio: Build It like the Pros, Second Edition, Course Technology PTR, 2010. “Three Signs Your Home Has Poor Indoor Humidity.” Lennox, 3 Mar. 2020, www.lennox.com/lennox-life/comfort-matters/getting-comfortable/three-signs-your-home-has-poor-indoor-humidity#:~:text=The%20ideal%20relative%20humidity%20for,of%20moisture%20it%20can%20contain.
May 15, 2023 · 13 min
How To Build A Soundproof Shed - Part 2
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop My contractor, Henry Thompson has been working on a soundproof studio here in Nashville that is built within a prefabricated shed. This is part two of the build series and it will go over the double walls, insulation, hat channels, drywall and installing the window. If you want to see part 1 of the series you can watch it here: https://www.youtube.com/watch?v=fuDgG2Wre9g 1) Double Walls In part one we talked about adding mass to the outside wall. In this lesson we are going over the double wall system. Henry and his team built out a seperate wall 1 inch from the existing structure to soundproof all the walls. He used special acoustic clips called IB-3 clips to attach the inside wall to the existing structure. These clips are specially designed to reduce sound transmission traveling from the existing structure to your inside walls. 2) Spray Foam Now spray foam does not help with soundproofing, but it does help with moisture issues. Because the roof is not vented Henry opted to use spray foam on the entire existing shed walls and ceiling. This allows proper insulation so the ceiling does not have condensation build up. This also helps tremendously with ensuring the roof system is airtight. Traditionally a cathedral style ceiling like this one would need soffits to vent properly. The problem with this method is that it means your ceiling doesn't get the double wall system you need for proper soundproofing. 3) Putty Pads and Insulation After the spray foam was installed, Henry and his team installed putty pads around all outlets and electrical boxes. This ensures that sound cannot easily transfer through the boxes behind light switches, outlets and overhead lights. Next, the team installed regular pink insulation in all of the wall and ceiling cavities. This is an important part of the soundproof wall design and the spray foam is not enough for proper soundproofing. 4) Hat Channels and Loft Floating Floor Henry and his team installed hat channels and IB-1 acoustic clips on all of the ceilings in the studio and along the beam supporting the loft. The hat channels decouple the two layers of drywall from the ceiling making it soundproof. The loft posed a difficult soundproofing problem. In the end, Henry floated the loft floor using some U shaped auralex floor pads. These are not usually something I would recommend, but in this situation we had to improvise some to soundproof the loft as best as possible. Henry added mass to the loft floor to help isolate it from the entryway below. 5) Drywall, Green Glue and Acoustic Caulk Once the insulation is in and the hat channels are installed the next step is adding the two layers of 5/8" drywall with Green Glue in the middle. The two layers of drywall add the needed mass to soundproof our walls and ceiling and the Green Glue helps stop lower frequencies and increase isolation due to damping. Once the drywall is in place they caulked the floor to wall, wall to ceiling and all corners with acoustic caulk to make sure the entire system is airtight. 6) Barn Doors The shed came with two barn doors. This also posed a challenge to our team because the doors are large and not very heavy. Henry came up with the solution of adding two layers of 5/8" drywall with Green Glue to the back of each door. The doors will not be soundproof until the project is complete, but this will add some much needed mass to the front door system. 7) Mini Split (Heating and Cooling) For heating and cooling needs, Henry and his team installed a Mr. Cool mini split on the back floor joist under the loft. This also allows plenty of space for the piping to run through the walls and out to the condenser. Remember, mini splits offer quiet heating and cooling, but they do not offer fresh air. For that you need a separate ventilation system. 8) Window Lastly, Henry and his team installed a large outside window on the front wall. This window is made of laminated glass and is thick to help stop sound. Henry created a frame for the window to sit in and then sealed any air gaps using DAP AMP, which is an all weather sealant. This sealant is important to keep the window airtight. Once the sealant was in place, Henry installed the outside trip around the window using a nail gun.
May 8, 2023 · 7 min
How Much Fresh Air Do You Need In Your Soundproof Studio?
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop If you have been following my youtube channel, emails or podcast for some time you may know that I am a big fan of having ventilation in your soundproof recording studio. The reason is that when you soundproof a room correctly the room will be airtight. This means you will not have any fresh air circulating in and out of the room. Contrary to popular belief, mini-splits and home HVAC systems do not provide fresh air unless you have a fresh air system in place. Most older homes do not have fresh air systems because they were not necessary. Older homes tend to have so many cracks and small holes that the air from outside can make its way in. Newer homes on the other hand are build tighter, meaning they are similar to our soundproof rooms and need fresh air systems incorporated into the design. 1) How Much Fresh Air Do You Need According to Rod Gervais, the author of Home Recording Studio: Build It Like The Pros, a good rule of thumb is to provide 15cfm per person. CFM stands for cubic feet of air per minute. This is equal to 0.42 cubic meters per minute for my metric friends. Now the best way to provide fresh air to your home is to use either an ERV or HRV. This article will not go in depth into what they are, but just know that an ERV (Energy Recovery Ventilator) will help recover moisture and heat during ventilation while an HRV (Heat Recovery Ventilator) mainly helps recover heat during ventilation. So when you are buying your ERV or HRV you need to know what size you unit you will need. 2) Buying the Right Size Ventilation System So for my studio I am usually the main person working in my space. I occasionally will have clients and studio musicians in the space, but this leads to a total of 3 people max. I would there for want an ERV that delivers around 45 CPM to satisfy my ventilation needs. Now if you have a studio that has full bands in the live room or control room you will need a larger unit. For example, five people would need 75 CFM of airflow. 3) Sizing The Unit When you are looking for the right ERV or HRV for your home studio build make sure to begin your search by sizing the right unit. If we go back to our example before, I would look for an ERV that provides 75 CFM. Just doing a quick google search I came up with a unit that would work for this example. The Fantech AEV80 provides 80 CFM and would adequately provide enough fresh air for 5 people. I have a Fantech ERV and it has worked wonderfully. Conclusion So, it is not so complicated, but you do want to remember that each person in your studio will need 15CFM of fresh air. By incorporating a fresh air system into your studio design you are setting yourself up for success and lasting health in your soundproof studio for years to come.
May 1, 2023 · 17 min
Is SONOpan Good For Soundproofing?
FREE Soundproofing Workshop - https://www.soundproofyourstudio.com/workshop It seems everyday a new soundproofing product is introduced to the internet. Some of these products can be helpful for soundproofing, while many others are simply a waste of money. Today I will go over a popular soundproofing product called SONpan and let you know if it is worth installing in your soundproofing project. 1) What is SONOpan According to their website, SONOpan is made from 100% recycled wood and 100% natural binders.I am not sure what the natural binders mean, but it might be the glue or adhesive that holds the wood pieces together. The company who makes SONOpan is MSL and they are a Canadian based manufacturing company. 2) How is SONOpan Used According to their website, SONOpan is used directly on the studs of your walls and ceilings or over your existing drywall to "soundproof" your room. They also have a product called SONOpanX which is meant for floor installations. They claim it mostly helps with impact noise such as footfall noise or bowling balls dropping on a bowling lane, but not so much with airborne noise. 3) How does SONOpan stop sound transmission Okay here is the real question. How does this stuff work and does it work? Again, according to their website they have trademarked the term "Noise Stop Technology." This means nothing technically, but is a good marketing tactic. Based on everything they say on their website it looks like SONOpan is really good at absorbing sound. This is similar to fiberglass insulation which has high absorption coefficients across the frequency spectrum. Here is how they say their panels work: "SONOpan has over 17,000 impressions in both sides of the panel resulting in a varying density throughout. When it comes to soundproofing, each frequency range has a corresponding sound wave where the peaks and valleys of that range are a certain size. The peaks and valleys in SONOpan are what make it extremely effective at soundproofing." - SONOpan Website Here is where they lose me. Soundproofing is not the same as sound absorption. Soundproofing involves adding mass to your walls, making sure they are air tight, using insulation in your walls, and making sure your walls are decoupled from the outside structure. SONOpan does none of those things. SONOpan may be good at helping the acoustics in your room, but I don't understand from simple physics how it could help with soundproofing. Next, fiberglass insulation can absorb frequencies down to 125hz. However, to absorb frequencies in a room below 100hz you need pressure based absorbers like helmholtz resonators or membrane absorbers. A piece of thin wood fiber will definitely not absorb low bass frequencies. "The peaks and valleys in SONOpan" are what help with high frequency absorption most likely above 500hz. Again, this product may be a good alternative to acoustic panels in your studio, but I would not use it for soundproofing. 4) What are the SONOpan STC ratings STC or Sound Transmission Class ratings are a way to compare different soundproofing assemblies with each other. The higher the STC rating the better that assembly is at attenuating sound between 125 hz and 4000 hz. This is roughly the frequency spectrum of human speech, but it does not account for frequencies from low bass, kick drums, trucks driving by, airplane rumble, helicopters buzzing, or lawnmowers nearby. So when we look at STC ratings claiming to soundproof a room we need to be aware that low bass frequencies are not being accounted for. The best way to attenuate low frequencies is to add mass to your assembly. The best way I recommend soundproofing a wall is to use what I call the double wall assembly. Here is what SONOpan says they get from: 2 layers of 5/8" drywall>wood studs> R13 insulation> 1" air gap > R13 Insulation> wood stud> SONOpan> 2 layers of 5/8" drywall. image source: SONOpan Website Notice the STC rating is 68. As a side note, I did not find any lab test results for their STC ratings, which means we are taking their word for their data not an independent third party lab. When I reached out about their lab tests, they responded by telling me SONOpan is not yet available in the United States, which did not answer my question. Now let's look at the same wall STC rating without SONOpan. Notice the same wall design without SONOpan gives you an STC rating of 63. Now can you hear the difference of 5 STC points? The answer is not really. STC ratings are not a perfect example of how we perceive soundproofing either, so small differences in numbering at not as noticeable as say an STC of 45 versus 68. Next, here is another STC chart from a company called The Soundproofing Company. This diagram is from the Soundproofing Company website. This wall assembly is essentially the same design as the previous two accept that it includes two layers of Green Glue between the two layers of 5/8" drywall. As you can see the STC rating for this wall assembly is 73. This is better than 68 and 63. Again it would be best to double check these STC ratings with the verified lab test data just to make sure the data is accurate. The key takeaway is that the main thing "soundproofing" all three of these walls is drywall, the airspace, the insulation and making sure it is airtight using acoustic sealant. The Green Glue and SONOpan may add a few STC numbers, but it is not earth shatteringly different. Conclusion When it comes to soundproofing there really isn't some secret technology that will suddenly make your sound go away. The design of your walls and ceilings and floors really comes down to some fairly simple design concepts. The use of additional soundproofing products like Green Glue and SONOpan may help a tiny bit, but consumers should really ask themselves if it is truly worth the added cost. The main cost of soundproofing your walls is going to be the cost of lumber, drywall and insulation. These materials will soundproof your wall if you build it correctly. Adding SONOpan seems like a waste of money to me. As of right now SONOpan costs $29.63 per 4ft x 8ft panel. 5/8" drywall costs $17.87 per 4ft by 8ft panel. I would always use 5/8" drywall over SONOpan because it adds mass. At the end of the day mass will help way more with soundproofing than anything else. Lastly, SONOpan has very little mass compared to 5/8" drywall. 5/8" drywall weights 70.4 Lbs whereas SONOpan only weighs 26 Lbs. To be completely honest, I don't see how SONOpan soundproofs at all. I could believe that it absorbs sound, but remember absorption is used for room acoustics not soundproofing. I would not recommend using SONOpan and I hope you now have some solid science and facts to prove why you should say no to some flashy soundproof marketing with SONOpan.
Apr 24, 2023 · 12 min
Do You Need Extreme Soundproofing?
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop There are times when the most powerful soundproofing techniques are needed. In this article I will go over the techniques that yield the most isolation for your soundproof design. These techniques may be needed if you have an especially loud source, like drums, you need to isolate or if you live near an especially loud neighbor, like an airport, and need to keep those sounds out of your studio. 1) Let's Review The Basics To understand the best isolation techniques we need to revisit the fundamentals of sound isolation. To soundproof a room we need three things: a) Mass b) An airtight room c) decoupling from our outside structure Mass involves adding lots of weight to our floor, walls and ceiling. It really is as simple as that. The more weight your assemblies have, the better your sound isolation will be. The single most useful tool for increasing isolation is to add mass. Next, we have air. For a room to be soundproof it must be airtight. This means every possible hole must be filled with acoustic caulk, acoustic putty pads, or special acoustical seals around doors. Even a small hole will let in sound, so we must ensure the room is sealed completely. Lastly, it is important to fully decouple the outside structure from the inside structure. This is the common term "a room within a room." For extreme soundproofing we are going to use the best decoupling techniques to ensure sound does not travel through our structure into our soundproof room. 2) Extreme Soundproof Floor The best soundproof floor is easy. It is a concrete slab poured over earth. Yup, no second stories here. For the best most extreme soundproofing you need to stay close to the ground. A concrete slab poured over earth will off you the best sound isolation period. Done deal! 3) Extreme Soundproof Walls If you need to keep out the sound of a kick drum, an electric bass amp, or the rehearsal of a heavy metal band you are going to need some powerful walls. Now you may have heard a term STC. It is helpful, but misleading. The reason? STC only measures frequencies down to 125hz. The most complained about noises are always bass or low frequencies below 125hz. I know, this is a total bummer. It means we have no way of knowing for sure if our soundproofing will fully work in the low frequency range. Yup, it sucks and I wish the labs would measure lower, but I believe the reason is they cannot guarantee accurate results sub 100hz. Don't quote me on that, but I did read it on the internet and it would explain this issue with STC ratings. So, the best you can do is build the most soundproof wall within your budget and available space. Here are some ideas for a super soundproof wall. A) Two Concrete Walls with Compacted Sand Now, this is extreme but you could build two concrete block walls filled with dry compacted sand and achieve very high isolation. It is important to put fiberglass insulation between your two walls to achieve maximum isolation. The minimum distance recommended between the walls is 1", but you guessed it, the greater the air gap the greater the isolation. So, if you had the budget and space you could put a 1 foot air gap and really attenuate those low frequencies. B) A Double Walls System With 4 Layers of Drywall and Green Glue Now, this is hardcore! We know that a double of mass will increase isolation by about 5dB. It may not seem like much, but it does help, since we hear a halving of sound at 10dB. That's like turning the volume knob on your room. Here is the plan. Notice on the chart below that the best STC rating is the two walls with an air gap and two layers of drywall on each side with fiberglass insulation in the middle. To get even better isolation we can add two more layers of 5/8" drywall to each side. Now to go crazy, we can get even more attenuation by adding Green Glue in between the two layers of drywall on each side. Just like our concrete wall we can increase the air gap and achieve even more isolation. I am very confident that this would really deaden the sound of drums, loud band rehearsals and most of the low frequencies. *A Word Of Warning - Soundproofing is not perfect. You could spend $150,000 building a concrete bunker and maybe still here 40hz. The goal is to turn down the volume of sound in your studio to an acceptable level for your neighbors and you. 4) Extreme Soundproof Ceiling Now that our floor and walls are super soundproofed we need to tackle the ceiling. The best way to soundproof the ceiling will be to frame it off the inner walls. So, with our concrete blocks you can build a frame off the inner block walls and with the wood walls you need to frame of the inner wood wall. Now, it's best to consult with a professional if you don't know how much your new framed ceiling will hold. You guessed it, we are going to layer 4 layers of drywall on our ceiling to match our wall mass. Add that Green Glue for good measure if you like. It is important to remember that with soundproofing we are only as strong as our weakest link. This means we want our mass to be consistent on all four surfaces of our room and outside walls and roof. That said, the air gap and mass on your ceiling also applies here. We want to not only add four layers of drywall to our ceiling, but ideally have the same mass, air gap and fiberglass insulation above our ceiling as well. This could be in the form of an upstairs with extra plywood layered on the floor. You could add 4 layers of drywall under your upstairs floor, but either way the consistency is key. If it is a roof above you, then you can add mass to your roof. Conclusion As you can see Extreme Soundproofing is, well, extreme. It takes some drastic measures to stop low frequencies from entering and exiting your room. The key take away from this article is that you have two levers to pull to increase isolation. First, you can tug on the mass lever. This means just beefing up all your assemblies with more weight. 5/8" drywall is the typical choice for ease of use and budget, but really anything with mass will work. Second, you can increase the air gap. By moving your interior wall away from the exterior wall you will increase isolation. I did those in order on purpose. The mass lever is by for the more powerful of the two. Start with mass and then add air space between walls if you can.
Apr 17, 2023 · 8 min
What Is A Reflection Free Zone?
FREE Acoustic Treatment Guide If you do some research on acoustics, chances are you will come across the term Reflection Free Zone or RFZ. In this article we will earn what it is and how to implement one in your own home recording studio. 1) What is an RFZ? The reflection free zone is an area in your room where you reduce all the first reflection off your side walls and ceiling, so that you get as clear of a listening field as possible. This concept really only applies to control rooms or home studios where you record and listen back in the same room. You can see in the image below from my own home studio that I have created an RFZ by hanging panels on both side walls and hanging an acoustic cloud directly above my head and slightly in front of me to absorb reflections off the ceiling. 2) How do you set up a reflection free zone? Once you have dialed in your listening position and your speaker placement then you are ready to treat the side walls and ceiling. To do this you will need a mirror and a friend to hold the mirror as you sit in your listening position. Because sound and light will both reflect off surfaces based on their angle of incidence, you can use a mirror to see where the sound waves will reflect on your side walls. Here is the process for finding where to hang your acoustic panels. 1) Sit in your listening position facing your speakers. 2) Have your friend hold the mirror directly against the wall in the front right corner. 3) Now have your friend move the mirror slowly along the wall towards the back wall. 4) Look at the mirror and wait until you see the front of your right speaker show up in the mirror. 5) At that location have your friend mark a pencil line on the wall at the left edge of the mirror. This is where you will hang your first acoustic panel. 6) Now have your friend continue moving the mirror along the wall until you no longer see the front of the right speaker in the mirror. 7) Mark the right edge of the mirror on the wall with a pencil. This will be the end of your acoustic treatment. Repeat this same process for the left wall. 3) Hang Your Acoustic Treatment Now you will have a space on both side walls between your two pencil lines that will need to be filled with acoustic panels. I like to build my own panels. If you want to build panels, here is a great tutorial on how to make high quality affordable panels: https://www.youtube.com/watch?v=bWqoRYnYlqE Once you have bought or built your panels then you want to hang them so that the middle of the panel falls at your ears height when you are sitting at the listening position. 4) Hanging Your Acoustic Cloud Lastly, we want to reduce the reflections from the ceiling. To do this we need to hang several acoustic panels over our head. The lower you hang the panel the more low end attenuation you will get. You will have to decide how low you want to hang your panel for aesthetics and ease of use in the studio. Make sure to hang your panel from your ceiling studs to hold up the weight. Conclusion That is the theory and application of a reflection free zone. if done properly, it can greatly improve the clarity of your stereo field. If you are looking to acoustically treat your own home studio then download my FREE Acoustic Treatment Guide to get a full overview of how to treat your own studio.
Apr 10, 2023 · 8 min
Do Not Angle Your Recording Studio Walls
If you are interested in learning more about how to acoustically treat your recording studio, download my FREE Acoustic Treatment Guide to dial in your home studio acoustics. Yes, you read that right. This is a very controversial topic out on the internet and I wanted to confront it head on. Everyone, and I mean pretty much everyone, wants to angle their studio walls. However, it is a myth that has been perpetuated through the ages. In this article I will give you all the science behind what angling walls really does. 1) It Will Not Fix Room Mode Issues Splaying walls will not eliminate room modes, but it may shift them slightly and help a little with diffusion. (Everest and Pohlmann 257) Everest and Pohlmann also cite a study by Van Niewland and Weber in their book that shows that room modes in non-rectangular rooms are in fact still there, but are harder to predict. This means that choosing a rectangular room using a room ratio that falls within the range of some of science's best acousticians: Bolt, Boner, Volkmann, Sepmeyer and Louden, will give you a room that has a more uniform distribution of modal frequencies in a room. (Everest and Pohlmann 254) This means you can predict the room modes and more easily treat them with room acoustic treatment. 2) You Will Lose A Lot Of Space In Your Room This may be the main reason not to splay your walls. First, let's be clear you can angle walls in a control room after the initial rectangular shell is created. This can be done using smaller framing timber and creating what is known as a reflection free zone around your speakers. It is important to note that even when a studio seemingly has angled walls, the true soundproof wall behind the inner studio is still rectangular. Now, angling walls will help with one thing and that is flutter echo. Flutter echo occurs when sound bounces between two parallel walls. It is the pinging sound you hear when you clap your hands in a room. It is also not desirable for recording studios. However, you can easily treat flutter echo in a room using acoustic panels. It is far cheaper to hang panels then to angle a wall. If you are dead set on angling your walls then you must angle them the right amount. According to the Master Handbook of Acoustics most walls are splayed "between 1ft in 20ft and 1ft in 10ft." (Everest and Pohlmann 257) This means if you splay one wall in a room that is 20ft long you will lose 10 square feet of space. I don't know about you, but that space is really useful and expensive to build. It's also important to note that in a control room you cannot just spaly one wall. You want symmetry in your room, so you would need to splay two walls losing even more space. You can see that splaying walls is not really ideal for any studio and especially a home studio. Conclusion There is not really much benefit to angling your walls in a recording studio. The cons far out weight the pros. One of the biggest factors in good room acoustics are using correct room ratios to start with and having rooms with large volumes. Splaying your walls will make it so you do not know the room modes and may actually make your room sound worse, and it will decrease the volume of your room, also making it sound worse. All problems with flutter echo and diffusion can be solved using carefully placed acoustic panels. You do not need to waste money and space angling walls. Works Cited: Everest, F. A., and Ken C. Pohlmann. Master Handbook Of Acoustics. 6th ed., McGraw Hill Education, 2015. pp. 257-259.
Apr 3, 2023 · 10 min
You Cannot Build A Soundproof Studio For Less Than $10K
Download my FREE Budget Calculator: https://www.soundproofyourstudio.com/calculator Want Soundproof Consulting: https://www.soundproofyourstudio.com/consulting Many potential clients reach out to me saying they have less than $10K to build a studio. The problem is that unless your studio is a 8x10 square foot room or smaller, chances are you will need to spend more money on your soundproofing project. Next, if you add in the cost of properly acoustically treating your studio, you are looking at another couple thousand dollars as well. In the video above I go over several different studio sizes and different budgets and show you with my soundproof studio budget calculator, exactly how much a soundproof studio will cost both if you build it from the ground up or inside an existing structure. To download the soundproofing budget calculator simply click this link: https://www.soundproofyourstudio.com/calculator.
Mar 27, 2023 · 14 min
How Soundproof Is My Studio?
FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop In 2020 I built a soundproof studio in my backyard. I had no prior experience building studios and I primarily used Rod Gervai's book, Home Recording Studio: Build It Like The Pros and the advice from The Soundproofing Company to design and build my studio. In this article I want to show you how soundproof my studio actually is, so you know what level of soundproofing you can achieve with these methods. 1) Taking SPL Measurements Before you build your studio you can take SPL measurements as many times as possible each day for 7 days to see what the highest reading you get is. This will be the SPL reading you need to soundproof against. In my studio I recorded an SPL of around 26dB. I took this measurement at 9:17am on a Monday morning. I then went outside and measure the ambient SPL of my neighborhood right outside the front door of my recording studio. The peak readings I got while outside was 57.6dB. So my transmission loss, or TL for short, was 31.6dB. Now it is important to note that not all frequencies have the same TL. So low bass frequencies will pass through my soundproof structure more easily than higher frequencies. Our goal with soundproofing is to try and reduce the sound outside as much as possible, while also reducing the loud sounds in our studio from coming out into the neighborhood. The best way to do SPL measurements for your studio is to take as many as possible at different times of the day. For example if you hear a siren passing by, pull out your SPL meter and record the level. This will help you get an idea for peak SPL levels in your studio. 2) What About Loud Music In My Studio? So in this test I did while playing my monitors, I reached an SPL of 87.6. When I closed my door while the speakers were still blasting the SPL outside dropped to 48dB. That means there was a TL of 39.6db. We also know that 48db was the ambient SPL of my backyard, so essentially my studio blocked out all the sound of the speakers at a very high listening level. I would never mix or listen back as loud as I was playing them. For drums there would certainly be a higher SPL in the studio and thus maybe a higher SPL right outside. I will have to do that experiment the next time I have drums in the studio. 3) Okay, so what do I hear in my studio? After working in my studio for 2 and a half years I can say that a take has never been ruined due to outside sound. That is not something I can say for my home studios previously. I can also say that when we play with drums or a full band in the studio the neighbors have never complained. I do not use the studio at all hours of the night, but I am confident it would not be a problem. Now I do hear some noises. Super powerful sub bass from cars in the apartment complex behind my house will enter the studio, but only in very low frequencies like 40hz and below. That is annoying, but you can EQ that off in most recordings. It is also fairly rare. I can hear thunder, but again it is only the low frequencies and it really doesn't come through much. I cannot hear rain at all. If a helicopter is flying really low I might hear some of its lower frequency energy, but it is not super loud. Lastly, if they are mowing the lawn, it really doesn't matter unless they drive the lawnmower right by my door or directly up against the back wall. 4) How My Studio Could Improve Soundproofing My door...oh my door. What a headache it has been. It has cost me so much time and money. If I could do it all over again I would have designed a communicating door system with Zero Industry seals going around each door. I also would have used the JH Brandt method of door construction not Gervais's. I would have used Corning 703 wrapped in fabric between the doors to increase transmission loss. One day I plan on adding a second door and better seals, but my budget currently does not allow for it and honestly it doesn't affect my work. It is more of a nerd and ego thing to make my door as soundproof as possible. This said, I am confident that I would hear even less if my door had been built better the first time through. I hope you have found this article insightful and helpful in understanding how soundproof a studio can be and how soundproof my studio is. Remember, you cannot eliminate all sound, but you can reduce it to an acceptable level for professional level recording.