Soundproof Your Studio

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. 

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: 

Here are the supplies that you might need: 

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. 

Noise Stop Systems is based out of the UK. They supply: 

They do not have any door seals. I would recommend them as a possible choice for your soundproof supplier. 

They are another UK store. They supply: 

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. 

This is, you guessed it, another UK based soundproofing company. They supply: 

I would only go with this store if the price is right. They don't have what most people will need. 

Now this is an American company, but they do ship internationally. However, you must call them for international orders. They supply: 

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. 

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. 

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. 

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.

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. 

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. 

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. 

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. 

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:

(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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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)

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. 

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. 

This is a debatable topic, but most books I have read and websites I researched said that 30-50% relative humidity is ideal. (Lennox)

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. 

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. 

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. 

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. 

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. 

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.

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

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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.

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. 

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. 

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! 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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.