Soundproof Your Studio

FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop

How To Build Soundproof Windows: https://youtu.be/JQiozaQcTkk

If you have ever wondered why soundproof windows are designed the way they are then this lesson is for you. This is also a great article on what acoustic holes are in windows.

Mass-air-mass resonance is when sound hits the outside pane of glass which then translates to the airspace between the two panes of glass. The air space acts like a spring and translates that sound to the second pane of glass. This transmission of sound waves causes a dip in the transmission loss of the window at a certain frequency. 

The frequency where that dip occurs depends on the thickness of the glass and the airspace between the two panes of glass. 

In the diagram below from The Master Handbook Of Acoustics, you can see how increasing glass thickness and increasing the airspace between the glass panes will decrease the frequency where the mass-air-mass resonance occurs. The goal is to get that frequency as low as possible for your recording studio design. 

In the next diagram of my own recording studio windows you can see that I used thick pieces of glass with a large air gap to reduce the frequency at which the Mass-Air-Mass resonance occurs. 

The second type of acoustic hole that happens with glass is known as the coincidence effect. This phenomenon occurs when the speed of the sound wave moving through air matches the speed of the sound wave already in the glass. This will cause an acoustic hole at that specific sound wave speed also known as the frequency. The acoustic hole will cause a dip in transmission loss letting that specific frequency through at a greater volume than other frequencies near by. 

The figure below from the Master Handbook Of Acoustics shows that with two panes of 1/8" thick glass with a 1/4" air-gap the coincidence frequency happens at 4k. This means sound at 4k will travel more easily through the window than frequencies above and below 4k. 

The formula for estimating the coincidence frequency is:

f=500/t

f= the coincidence frequency 

t= the thickness of the glass

If we look at my two studio windows the coincidence frequency of the 1/2" pane is 1000Hz and the coincidence frequency of the 3/8" pane is 1333Hz. 

The two dissimilar panes of glass make it so the coincidence frequency of one pane of glass cannot make it through the other and vice versa. This is a solution to preventing an acoustic hole in your soundproof window. 

Standing waves occur when two wave forms collide with each other head on either increasing the amplitude of the two waves, decreasing the amplitude or completely cancelling the wave out. Standing waves occur in the airspace between to panes of glass and can increase the resonance at certain frequencies thus causing acoustic holes. 

To combat standing waves, we put glass fiber on the inside our windows in the air space to absorb the sound waves that bounce around inside the airspace. This will help with some of the standing waves inside your window airspace. 

I hope this article has helped you understand why we build the soundproof windows the way we do. If you would like to learn how to build a soundproof window like I did in my studio you can check out this video: https://youtu.be/JQiozaQcTkk

FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop

How To Build Soundproof Windows: https://youtu.be/JQiozaQcTkk

I have been asked is it is better to use single pane or double pane windows when soundproofing. In this article I will go over which type of window is best and what I recommend for your soundproof recording studio. 

Single pane windows also known as single leaf or single glazed windows are what most residential windows are. They are not good for soundproofing and should be avoided. 

Single pane windows only offer an STC of 25, which is far below the ideal recording studio window that would have an STC of 50+. 

It is important to note, that if you do have to use a single pane window then the thicker the glass the better. As you can see in the graph from The Master Handbook of Acoustics, the sound transmission loss increases as the glass thickness increases. 

Lastly, if you can fully seal a window, meaning you can't open it, then your transmission loss will increase by another 3-5db. 

Double pane windows also known as double glazed or double leaf windows are better at soundproofing, but still not ideal. A readily available double pane window from your window retailer will only have an STC of 38. This is still far less than needed for a recording studio. 

For this reason I highly recommend buying a soundproof window from a commercial acoustic window supplier like Overly or Soundproof Windows Inc. 

You can also build your own soundproof windows. Here is a link from my youtube channel on how to build Soundproof Windows: https://youtu.be/JQiozaQcTkk.

In the figure below you can see how differing thickness of glass can improve your double pane window design. 

Remember, don't waste money buying "normal windows." To keep your room soundproof you must use a commercial soundproof window or follow my video and build your own. 

FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop

Soundproof Ceiling With Hat Channels: https://youtu.be/tnNu9bFD4ck

You can significantly increase the isolation of your ceiling or floor by adding a layer of concrete onto either your floor of your recording studio or the floor above the ceiling of your recording studio. In this article I will explain the method for doing this and compare the STC ratings of different designs with and without concrete. 

In my studio we used IB-1 isolation clips and 7/8" furring channel attached to our ceiling joists to decouple the drywall from the outside structure. We drilled two layers of 5/8" drywall into the furring channel to isolate the ceiling from the roof above. 

Below is a diagram of this design. 

You can increase the sound isolation of this design by adding a layer of self leveling gypsum concrete or cellular concrete to the floor above your soundproof ceiling. This will especially help with impact noise and low frequency transmission from kick drums and bass. 

In this diagram below from The Master Handbook Of Acoustics Sixth Edition we can see that adding a 1.5" layer of cellular concrete with a density of 105-120 lb/ft3 will increase your STC Rating and especially help in the low frequency spectrum. 

For comparison, a recording studio wall can get as high as STC 63 so to keep your floor roughly in line with that wall an STC of 59 is much better than an STC of 49. Remember, any weak link in your room will compromise the STC of the entire room. So having walls with a rating of 63 is only as good as your floor, door and window STC ratings. 

In this diagram we see that having access to both the ceiling below your floor and the floor above will give you the greatest isolation. If you live in an apartment with only one floor this may reduce your ability to isolate your floor and ceilings using this design. 

In this diagram from The Master Handbook Of Acoustics we can see that when both systems are using resilient channel, but one has the concrete on the floor above the concrete floor performs better across the entire frequency spectrum. 

From this diagram we can see that the resilient channel and 5/8" drywall gives you an STC of 47 while the added concrete above with the resillient channel and drywall gives you an STC of 59. Notice how you get 10db of added transmission loss at 125 Hz with the concrete. You also get 15db of added loss at 500Hz and 20db at 2KHz and above. 

There is a huge benefit in adding mass to your floor above to get greater isolation. 

First, we learned that adding mass in the form of concrete to the floor above will increase your STC ratings across the frequency spectrum. We also learned that to get the maximum isolation you ideally would have access to the floor and ceiling below. Lastly, it is important to consult with a structural engineer before adding the concrete to ensure your floor can handle the extra load.  

FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop

Soundproof Ceiling With Hat Channels: https://youtu.be/tnNu9bFD4ck

There are several options when it comes to soundproofing your ceiling. In this article I am going to explain the isolation hanger method. This will give you superior results when compared to the hat channel system, but may cost more and requires doing some basic math before diving in. 

Let's take a look at how to build an isolated hanging ceiling. 

The basic way this soundproofing method works is that the hanger when activated with the right amount of weight will isolate your ceiling from the rest of the structure. You can see in the diagram below how the isolation hangers hold up 2x4's that span your room and then you drill in two layers of 5/8" drywall into the 2x4's. This way your ceiling is completely detached from the floor above. Sound does not travel through the hangers thus making your ceiling soundproof. 

In his book, Home Recording Studio: Build It Like The Pros, Rod Gervais recommends using Mason Industries WHR Hangers.  These hangers come in different colors based on the weight of the ceiling you are hanging. 

A way to calculate the amount of hangers you need is to look at the weight load in a 4ftx8ft area of your ceiling. Drywall comes in these dimensions so it makes the math a bit easier. Now if your current ceiling joists are placed every 16" OC then you will likely need four hangers per 4ft by 8ft area of your ceiling. This means we need to calculate the weight of the wood holding our drywall plus the weight of the drywall to determine the total load on our hangers. Here is the math:

Two sheets of 5/8" Drywall = 140.8Lbs

Two spans of 2x4 at 4' in length = 9lbs

The total load for that 4'x8' area = 149.8lbs 

Now that we have the total load let's divide that by the load per hanger. To figure that out we simply divide the total load by 4 and get 37.5lbs per hanger. 

If we look at the mason industries website we know we will need to buy the Green hangers with a maximum capacity of 60lbs per hanger. 

Building the ceiling is relatively straight forward. You want to hang your clips in the middle of each bay using 1/4" hook bolts. (See the diagram below to get a visual). Next, attach 1/4" hook bolts to your new 2x4 ceiling joist and attach it to the WHR Ceiling Hanger. Add insulation to both the underside of the floor and in the new cavity of the hanging ceiling. Lastly, attach two layers of drywall to the hanging ceiling joists. Finish up by using acoustic caulk where the ceiling meets your walls to make the gap airtight. 

Overall this is a great soundproof ceiling design. The main things to think about are how much ceiling height you are willing to lose with the hangers and how much isolation you need. This design will probably deliver better isolation than the hat channel style design I used in my studio. The downsides are potential added cost and the extra work of calculating the total weight of your ceiling. 

FREE Soundproofing Workshop: https://www.soundproofyourstudio.com/workshop

Owens Corning: https://www.buyinsulationproductstore.com/owens-corning-703-fiberglass-acoustic-board-2-3/

If you want to save some money and can't build a concrete floor then this budget floor option is for you. 

Now, I know soundproofing and the term "floating floor" are almost synonymous, but the truth is that a floating floor is not always the best option. In fact, a concrete slab will always be the best way to soundproof a room. 

The reason is that concrete has a ton of mass and will do a better job of isolation across the entire frequency spectrum. For this reason I always recommend you start with a concrete slab. However, sometimes a concrete slab is just not an option. 

If you are building on a second story, on top of a crawl space or simply don't have the budget to pour a concrete slab then a floating floor is for you. 

1) Use Rigid Fiberglass

First, lay down a layer of rigid fiberglass insulation across your entire floor, but leave a gap between the wall and your fiberglass. I like to use Owens Corning 703 and I would use the 4" or two layers of the 2" to giv you the most isolation. You also don't want the fiberglass fully compressing to the existing floor when you add weight on top of it. 

2) Add 1x4 Strapping 

Add 1x4's in a pattern throughout the room to attach the drywall too. These could be every 16" on center or 24" on center depending on building codes and your budget. 

3) Add Two Layers of 5/8" Drywall

Add two layers of 5/8" Drywall on top of the fiberglass and 1x4" boards. Screw the drywall into the strapping boards and make sure to lay the drywall boards in opposite directions for each layers so the seams don't line up. 

*As a bonus you can add Green Glue in between the two layers of drywall to increase your soundproofing. 

4) Add Turned Up Glass Fiber Around The Edges

Add a layer of turned up glass fiber around all the edges of your room to ensure the floating floor does not touch your walls. 

5) Add Your Finishing Floor

Add your flooring on top of the drywall. This could be laminate flooring, carpeting, hardwood or engineered hardwood. 

6) Add Base Board and Acoustic Caulk

Lastly, you will add your base board on top of the fiberglass insulation. Leave a small gap between the base board and your finished floor and run a bead of acoustic caulk along the air-gap. This will ensure your room is still airtight while also not transferring vibrational noise through the baseboard to your floor. 

FREE Soundproofing Workshop - https://www.soundproofyourstudio.com/

Owens Corning: https://www.buyinsulationproductstore.com/owens-corning-703-fiberglass-acoustic-board-2-3/

Iso-Pads: https://www.soundaway.com/IsoTrack-stud-isolator-250pk-p/16203.htm

 0:00- Intro

0:41- Why You Shouldn't Float A Floor

1:59 - Iso Pads 2:42 - Fiber Glass

3:26 - Perimeter Board

3:56 - Two Layers Of Plywood

4:20 - Caulk Around Perimeter

4:39 - Add Finished Flooring

FREE Soundproofing Workshop - https://www.soundproofyourstudio.com/ 

FREE Soundproofing Budget Calculator: https://www.soundproofyourstudio.com/calculator

Today I want to give you 10 reasons you may not be ready to jump into building your dream soundproof home recording studio. This article is meant to give you pause and address some things you may not have thought of with the goal of saving you time and money. 

If you don't own your house or apartment then do not plan on building a soundproof studio. Soundproofing requires a lot of construction and cost and you want to put that into a house you own. 

Soundproofing is the method of construction that decreases the amount of sound that comes through floors, walls, ceilings, windows and doors. Acoustic treatment are figerglass panels that you hang on your walls to reduce acoustic reflections in your room thus making it sound better. You want to get these terms straight before jumping into a studio build. 

Before you take on a project of this size you need to have a rock solid idea of how much it is going to cost. Otherwise, you will end up owing more money than you have and never finish the project. Make sure you have a budget in place and have agreed upon that budget with your contractor. 

Don't have a budget: Use our FREE Soundproofing Budget Calculator to make one. 

If you keep on researching, watching youtube videos, reading blogs, reading books and still don't feel rock solid on your plan than you are not ready to build your soundproof studio. You want to be certain what you are going to build will in fact be soundproof. 

It is logical to think that the wall with all the noise on the other side of it is the one you need to soundproof. This is logical, but not correct. A soundproof room is an all or nothing endeavor. It is lie a fishbowl. One small leak and the whole bowl will drain. If you have one small whole in your soundproof room the whole room will be compromised. 

You cannot build a full soundproof studio alone. At the very least you will need some construction help even if you are doing it yourself. You must have a great contractor, electrician, and HVAC specialist. If you have not gotten your team together then you are not ready to soundproof your studio. 

If you build a soundproof studio, but do not acoustically treat it then you will just have a really isolated echo chamber. To finish your studio correctly you must know what panels to use and where to place them. If you don't know how to acoustically treat your room then you are not ready to soundproof. 

If you don't think you need fresh air in your new airtight soundproof studio then think again. We exhale C02 and a buildup of C02 can cause headaches and fatigue. You don't want stale air in your new studio. If you don't have a plan for ventilating your studio then put on the breaks on your build. 

If you are exhausted from endless research and still can't decide on how to build your studio then you need some outside help. It is time to look for a resource that will guide you step by step towards building your soundproof studio. 

It is tempting, but soundproofing is an all or nothing endeavor. You must commit to doing it right or else all of your hard work and money will be wasted and you will not get the results you desire. 

FREE Soundproofing Workshop - https://www.soundproofyourstudio.com/

It is important to note that masonry walls will transmit impulse noise through their structure more easily than gypsum board so isolating the wall from outside sources or other parts of your structure is important.

Adding mortar or compacted sand inside concrete blocks will increase isolation. Creating a double wall system with glass fiber in the air gap will also increase isolation.

Summary Of STC Walls

In the chart below from Master Handbook Of Acoustics by F. Alton Everest and Ken C. Pohlman, we can see that the best isolation is from double concrete block walls spaced 6" apart. This system will work really well, but uses a ton of square footage in your studio. A double wall with drywall and wood framing can achieve an STC of 63, so single masonry walls for studios are not as good as a double wall system. However, single masonry walls are much better than single drywall and wood framing. A single wall in a typical home only has an STC of 36.

Comparing Concrete Walls

If we look at another diagram from the Master Handbook of Acoustics we find that a single 12" concrete wall has an STC of 51 and two concrete walls spaced 6" apart has an STC of 59. The double wall system is clearly better than a single concrete wall. Remember adding insulation in the air gap will increase the STC as would adding more mass to the outsides of both or either wall. Also remember that although the STC is not comparable to our wood framed double wall the low frequency transmission loss is going to be greater in a concrete wall than a wood framed wall.

If we look at a third diagram from the Master Handbook of Acoustics we can see how different brick wall designs perform. Notice that a single brick wall is not ideal. Adding wood, furring channels or gypsum board to a brick wall will increase transmission loss. The two brick walls with glass fiber in the middle will give the best transmission loss across the frequency spectrum.

Using Masonry Walls and Wood Framing Together

I believe the best option when soundproofing is to use a masonry wall as your outside wall to the world or the rest of your house and then frame an inside wall with at least a 1" airgap using wood framing and two layers of drywall with green glue in the middle. This will give you an STC in the 65 or higher range and will also increase your low frequency isolation. I also believe this system will save you in materials cost and floor space in your studio design.

FREE Soundproofing Workshop - https://www.soundproofyourstudio.com/ 

I have had many of my soundproofing students ask me where to use acoustic caulk. This is one of those important but often glanced over parts of soundproofing. In this article I will teach you exactly where to use acoustic caulk for your soundproof studio.

1) Where The Walls Meet The Floor

Anywhere the drywall meets the floor you need to run a bead of acoustic caulk along that seem. You can also leave an 1/8" gap between the drywall layers and the floor and push in backer rod into the gap and then fill it with acoustic caulk. This will give you just a bit more isolation from the floor and the wall.

2) Where your walls meet in the corners of your room

Anywhere you have two layers of drywall meeting in a corner you need to place acoustic caulk along that seem. If you want a bit more isolation with your walls you can leave an 1/8" air gap between your first layer of drywall and put in backer rod and acoustic caulk. Then you can do the same thing with the second layer, adding backer rod and acoustic caulk. This will help isolate your walls from each other.

3) Where The Walls and Ceiling Meet

Anywhere your walls meet your ceiling you will need to place a bead of acoustic caulk along that seam. Again, to add isolation you can leave an 1/8" air gap and place some backer rod and acoustic caulk in between both layers of drywall.

4) Anywhere there are small holes or cracks

Construction is not perfect, but your room needs to be airtight. To accomplish this we need to use acoustic caulk around all electrical boxes for lights or light switches or plugs. Use acoustic caulk where the drywall and boxes meet. You can use it around small holes like we did when running an ethernet cable through the wall. Use your best common sense when it comes to ceiling up any holes in your room.

***Affiliate Link**** Home Recording Studio: Build It Like The Pros by Rod Gervais - https://amzn.to/3vFI8OD

FREE Soundproofing Workshop - https://www.soundproofyourstudio.com/

 You can build a door from scratch and fill it with sand to create a soundproof door. In this article we will go over how to build your door.      

Materials 

3-5 bags of dry sand  

Lots of Wood Glue  

2 Sheets of 1/4" or 3/8" Plywood   

2 Sheets of plywood hardwood veneer  

3-5 seven foot 2x4 studs     

How To Build The Door 

1) Start by cutting all of your 2x4's lengthwise so the boards are now 2x2's or really 1.5" x 1.75" nominally.   

2) Cut 1 piece of plywood so that it fits the size of your doorway minus 1/8" or 3mm on all four sides.   3) Attach the 2x2's to your plywood building a frame for the door. Use cross braces at the top and bottom and in the middle to keep the door square.  

 3) Measure 36" from the bottom and create 3 pieces of 2x2's for your lockset. These are the three middle studs you see in the picture above.  

4) Next pour the sand into your door where the spaces are.   

5) Glue and staple the top piece of plywood over the sand filled door.   

6) Finally glue the hardwood veneer to both the front and back of your door.   This door will be very heavy so make sure to use multiple people to lift it and use at least 4-6 hinges when hanging it.  https://jhbrandt.net/ 

***Affiliate Link**** Home Recording Studio: Build It Like The Pros by Rod Gervais - https://amzn.to/3vFI8OD

 0:00 - Intro

1:15 - What Materials You Need

 2:24 - How To Build The Door

 5:48 - Conclusion