acoustic panels & how to soundproof a room

How to Set up the Acoustics of Your Recording Room  

One of the most important things for any recording artist to understand is the acoustics of the room that he or she is working in.

What Are Acoustics?

Acoustics refer to the sound properties of a given area or room.

What Do Acoustics Have to Do With Anything?

The acoustics of the specific room or venue that you’re recording in have a huge effect on the quality of the overall recording that is produced.

Let’s say, for example, that you’re in the Grand Canyon (use your imagination) where you have your personal studio set up. When you speak, you’ll probably notice that the canyon produces a lot of echo or ‘reverb,’ so to speak. This same reverb will be picked up in your audio recording as well, so when you go to mix it in with the track that you’re recording with it will ‘muddy’ up your recording.

While this is a very unrealistic and extreme example, it outlines the same underlying principle of audio recording in normal spaces.

Remember that ‘reverb’ thing we were talking about? It’s a great feature to add to your vocals as an effect to give them that ‘stage presence’ feel as if the vocals were performed in a big room. However, reverb can destroy your vocals if they are already present in the recording.

What is Reverb?

Reverb is basically the reflection of sound from the surrounding walls or sources in the room or area the sound is being produced in. It’s important to not get reverb confused with echo. Echoes are Reverbs but Reverb isn’t always an Echo.  Sound confusing? Don’t worry we’ll break this down further.

You probably have a great idea of what an echo is. A sound is made and you can hear it a second or two after the fact. If you’ve ever yelled in a large gymnasium or auditorium, you more than likely heard your own echo.

Reverb works in a way similar to an echo in that it refers to that little repeating sound you hear after the effect. The only difference is that instead of repeating after a second or two, reverb generally occurs after a few milliseconds which gives the listener the impression that they’re still hearing just one original voice in live time.

Hopefully, this makes the statement – ‘Echoes are Reverbs but Reverb isn’t always an Echo’ – substantially more clear. It’s sort of like math when you learned that all squares are rectangles but not all rectangles are squares. If you still don’t understand this concept then don’t beat your brains over it, it’s not that big of a deal. For those that are enamored with the idea of echo and Reverb and want a more in-depth lesson, click here.

The main point of all of this is that there’s a 99% chance that the room you’re in right now emits some sort of reverb. When recording vocals of any sort you generally want to remove as much reverb as possible.

Why Would You Want to Remove Reverb if You Barely Notice It?

When audio recording, you are essentially striving to get the cleanest vocals possible. Reverb prevents you from doing so because that little delay on your voice that you can’t notice will be picked up by the recording. You won’t hear it yourself in the recording but it will make it a lot more difficult to isolate the cleanest parts of your vocals for mastering. Because there is such a short period of delay between your voice and the Reverb itself, it will be nearly impossible for you to split this from the recording.

Remember, when you hear an echo, it sounds somewhat like a tiny replica of your original sound. Echos are usually very faint in volume compared to the original sound and quality wise are substantially degraded from the original. The same is true of Reverb, so you can imagine how problematic this would be moving forward if you have a portion of your recording that is a degraded form of the original. Spoiler alert: It’s very problematic and often leads to an overall much lower quality recording than it otherwise would’ve been in a properly set up room.

How Should You Set Up Your Room?

Sound-wise, there are two important factors that you must handle in order to optimize your recording space for optimal sound.

  • The Room’s Acoustics – As mentioned earlier, this refers to the sound properties of the room itself. You want to make sure to remove a substantial amount of Reverb out of the room. However, you must be careful to not remove too much of the reverb out of the room or your vocals will sound very ‘dry’. By dry, we mean that your vocals will sound as if you recording them in a coffin underground somewhere and that’s dull and exciting. In this article we’ll tell you what you need to do in order to solve your reverb problem while still maintaining life in your recording. We’ll also give you useful solutions on what gear to buy or, if you prefer to venture the DIY route, we’ll provide tips and strategy for that as well. This article will outline the pros and cons of each method and give an overall verdict afterward.
  • Soundproofing the Room – This is a commonly overlooked, yet very essential part of setting up your recording room. If there is outside sound that travels into your room then it can ‘muddy’ up the recording, causing you to have a lower quality recording. By soundproofing your area, you can ensure that you’re only recording the content that you intentionally wish to record and nothing additional. In this article, we will explain to you in greater depth the benefits of soundproofing your room, what it does for your recordings and what items you should purchase or, if you’re looking to go the DIY route, some strategies and common tools that you can use to get the job done without paying for a professional to do so. We’ll outline the pros and cons and cost effectiveness of each of these methods as well.

 

Acoustics and Acoustic Panels

Before fooling around with your room’s acoustics, there are a couple things that you want to check for:

  1. It is beneficial if the room itself is a relatively small area to record in. This is important because if your room is too large, then whatever acoustic additions you make will have a negligible effect. Imagine you find yourself in the Vatican (that big church that the Pope stays in) and you laid acoustic panels on all the walls and recorded in there. Because of how spacious the room is, it would make a little to no difference in terms of reverb because the space itself will have a reverb effect for some lengthy, complicated physics reasons that we won’t get into in this article – just take our word for it, any industry professional will tell you the same.
  2. The room you’re recording in has a door or something to shut it. The greatest acoustic treatment for your recording room will all be for naught if there isn’t some sort of door or mechanism to close off the room while the recording is taking place. Otherwise, the reverb from non-acoustically proofed outside room will leak into your recording.

 

When optimizing the acoustics of your recording room, there are two main goals:

  1. Absorption – This encompasses the idea of removing that reverb we were talking about earlier. You accomplish this goal by putting up material on the walls of your room that does not reflect sound when sound hits it.
  2. Diffusion – Although it is discussed far less frequently than absorption when it comes to acoustics, it is equally important. Remember when we talked about the idea that removing all of the reverb out of a room could possibly render recordings too dull and ‘dry’? The process of diffusion in acoustics seeks to combat this potential issue. Certain material, when hung on the walls of your audio recording room will ‘diffuse’ the reverberations instead of eliminating them altogether. Diffusion is preferable to unfiltered reverb because, by diffusing or ‘scattering’ the reverb, it is evenly distributed around the room instead of it being reflected back directly from one source or surface (i.e. a plain white drywall). This is extremely useful because it allows you to have some life in your recordings without sacrificing quality.

Absorption Process

Now that you understand what needs to be done and why when setting up the acoustics of a room, we will now look at how to get it done – starting with the absorption process.

Typically, sound reverberates off of very solid and hard surfaces (dry wall) so can you imagine what surfaces don’t reflect sound? If you guessed something that’s the opposite of ‘very solid and hard’, then you’re correct. The most common product used to accomplish this goal would be the classic foam acoustic panels. They’re relatively inexpensive and can be found easily online here.

However, if you absolutely despise convenience and saving tons of time, there’s a DIY method that you can use as an alternative:

DIY Method for Absorption

If you can get your hands on a thick wooden board of some sort, then you’re in business. On that wooden board, you want to attach a cushioning fabric (blanket quickly comes to mind).

You may be thinking ‘Can’t I just tape a blanket to the wall?’  – The answer is no. This will not be a sufficient replacement for acoustic panels because merely taping a blanket to the wall will have a minimal effect on reducing the reverb because essentially the cushion will be applied to the flat walls of the room so it will allow the sound to still reach the wall and emit reverb. General rule of thumb when it comes to absorption in audio recording is this: The thicker the acoustic panels – the more noise that is absorbed.

So, once you’ve attached your blanket to this wooden board and made a makeshift ‘panel’, you can put this on your wall. Make sure that the back of the panel is flat. The back of the panel should be flat because if it is raised then the wall will be easily reached by sound and it will still have an opportunity to reflect whatever sound hits it, thus undermining the whole purpose of your arts and crafts project.

Once you have created a sufficient amount of panels, you can hand them around your room as you see fit.

What Do We Recommend: Purchasing Panels or DIY?

We absolutely recommend that you simply purchase the panels. They don’t cost that much money, they’re exponentially less hassle than the DIY method, and they’re way more likely to work. If you’re reading this article, chances are you’re not a sound engineer, so you’re working with a pretty large room for error without the advanced knowledge of sound engineering that was undoubtedly used in the design of the acoustic panels.

Ultimately, the DIY method is way too time-consuming, easily runs the risk of being less effective, and when its all said and done, there’s no guarantee that you will have actually saved any money in the process. With all these factors considered, it’s a wonder why anyone chooses to create studio panels using a DIY method.

Diffusion Process

For the diffusion process, you’re going to need some sort of material that can diffuse the sound in the room. We don’t have any clever way of asking you what you would need for this process, so we’ll just give you the answer: miniature cubbies.

You remember when you were in grade school and you had to put your belongings into a wooden box called a ‘cubby’? If not, here’s some pictures here. Those are what sound diffusors typically look like, except there are several more ‘boxes’ per square foot than you would see in a typical cubby because they are not used for storing items.

Also, every other box on a sound diffuser will be ‘closed’, or there will be some sort of wood on the front of the cubby to block the entrance.

Other examples of sound diffusor panels include wooden structures where every other piece of wood juts out from the structure itself.

The biggest takeaways you should know about sound diffusing panels are that they are almost always wooden and typically have a staggered feature of some sort (in and out, protruding and not) in a checkerboard arrangement.

How to Purchase

You can find diffusor panels for your studio here. There isn’t much to do with the diffusor panels after purchasing them, besides setting them up in the appropriate locations. The panels are pretty example, so one would need a very sizable budget in order to purchase them.

DIY Methods

There are a few DIY methods that can be used to mimic the effects of diffusor panels if you find yourself short on funds.

One very popular and easy DIY method is to take egg cartons to your wall. Although the material used ‘cardboard’ is not quite as effective as the wood that the panels provide, they still do a pretty effective job at dispersing sound around the room.

Another more official way would be to actually design the wooden boxes yourself using whatever saws and power tools.

What Do We Recommend: Purchasing Panels or DIY?

We’d recommend going the DIY method for this part of your acoustic setup unless you have a massive amount of disposable income available at your discretion. There are virtually no cheap options for diffuser panels that can be purchased, so expect to put out a respectable sum of money if this is the direction you choose to pursue.

In comparison, DIY methods can be several hundred dollars cheaper, much easier to undertake, and can yield comparable effects to purchased diffusers from a real vendor.

 

 

Soundproofing

As mentioned earlier, the art of soundproofing is different than applying acoustic treatment to a room. Soundproofing is the process of reducing a room’s susceptibility to picking up outside noises and vice versa.

This is important because even when you’re in a quiet environment, little sounds may still leak into your recordings which will ‘muddy’ them up. This is of great importance if you’re running an official studio where there may be more than one musical group recording at one time. You don’t want the sound from one of the groups to leak into the room where you’re recording vocals.

Assuming that you’re just setting up a private studio though, we won’t get into preventing the sound itself from leaking out of your studio, just the prevention of the sound coming in.

Before getting into how to soundproof, it is important to understand the constituent elements of soundproofing:

  1. Adding Mass to the room. The principle behind this falls in line with the sound theory that the more mass in your room, the harder it will be for certain noises to penetrate through. Although acoustic panels help meet this goal, there are additional methods that will help meet this goal as well.
  2. Sealing all air spaces. This technique is a little more self-explanatory than the other ones because by sealing air spaces, you will prevent addition noise from entering the room via those spaces (don’t worry you’ll still be able to breathe).
  3. Decoupling is a weird word that basically means to add insulation in the walls of your recording room to further reduce the impact of outside sounds entering. Unless you’re building your studio from scratch, its unlikely that you’ll be able or have desire to rip your walls apart and add insulation. However, this problem can be addressed by adding insulation within the walls that you added mass to in step #1.
  4. Damping/Absorption. As mentioned earlier, absorption will not be addressed in this soundproofing discussion because the acoustic treatment will address this concern and we are simply focusing on not having music enter your recording room rather than exiting. So instead, we will look at damping.Dampening is very similar to the act of adding mass to the room and by dampening a room you can usually accomplish that objective too. Basically, dampening a room is done through the installment of material that doesn’t vibrate to the room. This material can also be used to add to the mass of the room, which is how it can fulfill the objective listed in #1. Similar to absorption, it will have the effect of reducing noise from traveling outside.

For starters, it would be much smarter to go about soundproofing your room before applying further acoustic treatments or acoustic panels to it because soundproofing often involves some physical modification of the room itself that would require the removal of any acoustic features that have been applied to it. Thus, to save time and effort look at soundproofing your room first.

Below, we’ll look at how to follow through on some of these soundproof methods and what purchase and DIY options there are available before evaluating which one would be more feasible for getting started with their studio without an unlimited budget.

Please take note that not all of these methods may be necessary for the purposes of what you’re trying to do if you’re just starting off in the creation of your studio. While any of these methods can be applied singularly, they do have a cumulative effect as well if you decide to employ each strategy, so keep that in mind.

First, we’ll look at:

Adding Mass to the Room

As mentioned above, this is a fairly intuitive process – you’re looking to add mass to the room itself to assist your soundproofing efforts and the best way to do so is by making sure the room’s walls are as thick as possible. As noted earlier, the room you’re using has probably already been designed and reconstruction would cost thousands. So, is there an alternative? Fortunately, there is and that alternative is adding mass loaded vinyl.

Mass loaded vinyl is typically almost as heavy as lead, which adds substantial mass to the room and it serves as an excellent noise barrier. This can be added to your walls in addition to the floor to prevent vibrations that may come from those underneath you if there is sound there as well.

Here, you can find a great length for a solid mass loaded vinyl floor pad.

If you visit here you’ll find a link to purchase a solid amount of mass loaded vinyl.

There aren’t really any DIY methods that you can use to get around using mass loaded vinyl, so if you find the prices to be outside of your budget then you may just have to forego this feature altogether.

Sealing All Air Spaces

Perhaps one of the simplest facets of soundproofing is the sealing of all air spaces. As the name suggests, you can accomplish this by simply sealing the air spaces which will more than likely be the entry way to the room itself. This can be done by using an acoustic sealant.

The most common acoustic sealant used these days is ‘green glue’. This product can be found here. While it isn’t typically cheap, it usually last a fairly long time and is specially designed to prevent noise from entering or leaking from a specific room. By using this like a caulk for the spaces in your doorway and other entrances/exits, you can decently enhance your room’s current soundproofing capabilities.

There is no DIY alternative for this method of soundproofing either as the act of applying the green glue itself is a requisite element of sealing the air space. Any other soundproofing effort would be virtually wasted.

Decoupling

Decoupling is done by adding insulation of some sort between the walls of your recording room in order to further reduce the capacity for your walls to transduce sound vibrations. However, if you’re like most individuals creating a home studio then there’s probably no way you can feasibly restructure your walls without spending an absurd amount of money.

So what’s the alternative?

Refer back to the section we wrote about adding mass to the room. Remember that? Well, if you’re able to add in insulation between the pre-existing walls of the room and the mass loaded vinyl that you’ve chosen to use to add mass then you’ve created a very viable alternative to tearing down the walls of your recording studio and building from scratch.

So, what insulation should you use? If you figured ‘I probably can’t use the same insulation that my house has to keep me warm in the winter’ then you were right. What you need is acoustic insulation.

All the installation you’ll probably need can be found in this pack of 12 installation boards, found here.

Keep in mind that if you’ve already decided to forward with the mass loaded vinyl purchase, then you probably won’t suffer greatly if you opt not to purchase the acoustic insulation provided by the link in the former paragraph.

In terms of DIY methods, there are virtually none because material that would qualify for acoustic insulation is very difficult to find independently, if not impossible.

Be careful to not confuse acoustic insulation with the acoustic panels that you will need to use for the acoustic treatment of your room.

Damping

Damping is a great supplement for any of the above methods that were discussed (apart from sealing air spaces). Damping basically refers to the act of using green glue when applying the insulation, mass loaded vinyl, and other items that we discussed. Basically, the green glue not only works as a sealant but as a glue as well so its soundproofing abilities can be amplified with other soundproofing techniques.

 

Conclusion

In conclusion, this more or less covers just about everything you’d need to know about setting up the environment and atmosphere of your recording room.

As a quick review, just remember that soundproofing and acoustics are two distinctly different processes that both deal with the room’s sound. Soundproofing refers to eliminating sound leakage, both inside and out, and acoustic treatment refers to altering the actual sound properties of the room to maximize recordings.