One of the biggest sticking points newbies have when first getting started with home recording is…
They grossly underestimate the importance of room acoustics…
And assume that just because they have a nice instrument and a nice microphone…everything’s OK.
But the truth is…the acoustics of your room have more-to-do with sound quality…
Than perhaps anything else your studio….anything.
So rather than face months of frustration trying to figure out what you’re doing wrong…you might as well get this stuff handled right now.
Which is why in this post, I will walk you step by step through the entire process of designing an effective acoustic treatment setup for your home studio.
Ready? Let’s begin. First up…
Before getting started with acoustic treatment, it’s a good idea have a basic understanding of acoustics in general.
The good news is…you don’t need a degree in acoustical engineering to run a recording studio.
All you need is a few SIMPLE CONCEPTS. Starting with…
1. How Sound Travels in a Room
Whenever a sound is made in a room, here’s what happens to it:
- Starting at the source, it projects outward in all directions.
- A small portion of it (known as direct sound) travels in a straight line to the microphone.
- The remainder (known as reflected sound) bounces randomly between the surfaces of the room.
- Moments later, some of those reflections reach the microphone by chance.
Since direct sound does not interact with the room, its frequency balance remains pure, and its tone unaltered.
With reflected sound, each new reflection has the potential to CHANGE the original sound ever-so-slightly.
Depending on the size of the room, and the reflective surfaces within it…
This change could be either LARGE or SMALL…GOOD or BAD.
In most rooms it’s bad. And here’s why:
2. Why Most Rooms Have Poor Acoustics
Have you ever gotten to visit a grand cathedral like the one in this picture?
If so…did you notice how every sound in there is absolutely incredible?
That’s because, rooms like these are not only designed to LOOK beautiful…
They’re designed to SOUND beautiful as well.
The problem is…rooms with great acoustics require a LOT of space and a LOT of money to build.
And since most of us have neither…here’s how we fake it:
3. How to Fake a Great Room Tone
Way back in the 1960’s…
Someone invented the awesome machine known as the Echo Chamber.
This machine allowed engineers to simulate the reverb of a room OTHER than the one where it was recorded.
Over the years, the technology grew more sophisticated, and today…
Software programs known as digital reverb can simulate the sound of virtually any acoustic environment imaginable.
The only catch is…before you can add FAKE reverb, you must first remove the REAL reverb.
Here’s how it’s done:
4. How to Remove the Natural Reverb of a Room
Ever noticed those foam panels on the walls of recording studios?
While they might look super cool…
Their REAL purpose is to absorb sound reflections.
Normally, those reflections get recorded…
But with acoustic absorption, all that remains is the direct sound from the instrument to the microphone…which is exactly what we want.
That’s how it works “in theory”…
But in practice, many people find that absorption actually works best in combination with another type of acoustic treatment known as diffusion.
Here’s how it works:
5. How Diffusion Improves Your Sound
When you remove ALL sound reflections with absorption…
Many people find that the room sounds uncomfortably “dead”.
The solution here…is to allow a few reflections to remain, and to scatter them with diffusors.
Normally, untreated reflections create problems because they get trapped in one spot, amplifying some frequencies, while canceling out others.
This is how the natural frequency balance gets destroyed.
Diffusors work by scattering reflections so nothing gets trapped, and the natural tone is preserved.
With the right combination of both absorption and diffusion, you can transform the acoustics of virtually any room…into something capable of a world-class recording.
Now that you understand the fundamentals of acoustics…the NEXT step is applying these principles toward your room by adding some acoustic treatment.
But before we do that, let’s clear up a common misconception that newbies often have…
Soundproofing vs. Acoustic Treatment
Very often, musicians will use these two terms interchangeably, mistaking ONE for the OTHER…
When really, each one is completely different.
Soundproofing is intended to minimize the level of sound that travels in and out of your room by:
- by blocking them with heavy, dense building material.
- sealing up any air gaps in windows/doors.
The benefit here is…you can record whenever you wish, without worrying about you and your neighbors disturbing each other.
Acoustic treatment on the other hand, aims ONLY to control sound reflections WITHIN the room, to make better sounding recordings.
BOTH of these are valuable, but NEITHER does the job of the other.
And while soundproofing can definitely be incorporated as part of your acoustic treatment plan, it’s not technically acoustic treatment in itself.
So if you want to learn more about soundproofing, check out this post instead:
Otherwise, let’s continue…
Evaluating Your Bare Room
Too often, when novices first hear of the supposed benefits of acoustic treatment…
They immediately go out and buy stuff, without first diagnosing and evaluating the extent of their problem.
So…to find out how bad the acoustics in your room really are, here’s what you do:
Walk around the room, clap your hands as loud as you can from every spot, and listen closely to the reverberations that follow.
- In the WORST case scenario – you’ll hear a harsh metallic ringing sound, which typically occurs in small cubical rooms.
- In the BEST case scenario – you’ll hear a pleasant reverb, which typically occurs in larger rooms with high ceilings and lots of complex diffusive surfaces.
But most likely, the sound you hear will be somewhere in-between. Now…
- The closer it is to #1, the more absorption you will need to make the room sound as dry as possible.
- The closer it is to #2, the less acoustic treatment you will need in general, although virtually any room will still benefit from a little.
If you need some reference points to hear the difference between good and bad acoustics, perform the clap test in a wide variety of different rooms, and take notice of which types tend to sound best.
Then later on, when you begin installing acoustic treatment in your room, use the clap test constantly throughout the process to observe how the sound changes.
With each new addition, that nasty ringing should be becoming less prominent, until it disappears completely.
The 3 Elements of Acoustic Treatment
Getting your room to sound great with acoustic treatment requires of a combination of 3 items:
- Bass Traps – to absorb the low frequencies
- Acoustic Panels – to absorb the mid/high frequencies
- Diffusers – to scatter the remaining frequencies
Now let’s learn more about each one…
1. Bass Traps
The first and most important element of acoustic treatment to add to your room is bass traps.
If you can only afford 1 thing now, get these.
And here’s why:
Though commonly thought of as specialized tools for absorbing bass frequencies…
Porous bass traps actually are actually broadband absorbers, meaning they’re good at absorbing mid/high frequencies as well.
Which is why sometimes…bass traps alone can be enough to get the job done.
In small home studio rooms especially, where bass frequencies can be particularly problematic, bass traps are a MUST-HAVE.
To find out which ones I recommend, and get detailed instructions on how to set them up, check out this post:
2. Acoustic Panels
While many people think of acoustic panels as the primary “go-to” weapons to combat problems with studio acoustics…
The truth is, they’re almost completely ineffective at absorbing the lowest bass frequencies…
And should therefore be used as a supplemental tool…AFTER the bass traps are taken care of.
But here’s what they can do that bass traps can’t:
Because they’re thinner, and offer more surface area with less material, acoustic panels can provide greater wall coverage, for less money.
What that does is kill any standing waves that may exist between opposite parallel walls. Which is the one thing that bass traps can’t really do, since they’re primarily located in the corners of the room.
To find out which ones I recommend, and how to set them up, check out this post:
Most folks today believe that for smaller rooms…
Like those of most home studios…
The effectiveness of diffusion is greatly reduced, if not neutralized.
For project studios, that’s good news, because it eliminates the need for expensive diffusers.
Many people don’t use them at all. Yet others disagree completely, and use tons of them.
So it’s totally up to you. Just remember to get the absorption part handled first…then if you want to add some diffusers later, here are 3 great options I recommend:
3 Great All-in-One Packages
If you haven’t figured it out by now…buying all this stuff individually can be a HUGE hassle.
Which is why companies like Auralex and Primacoustic offer complete “room packages” to simplify the process and eliminate ALL the guesswork.
For home studios, here are 3 great packages I recommend:
1. Primacoustic London 12
Known as one of the top brands in acoustic treatment…
Primacoustic offers a ton of great solutions for home studios…
Including their current line of room packages known as the London Series.
I recommend the mid-sized London 12, which as you can see in the picture, is a perfect solution for standard sized rooms.
Here’s what’s included:
- Two 24″ x 48″ x 2″ Broadband Panels
- Eight 12″ x 48″ x 2″ Columns
- Twelve 12″ x 12″ x 1″ Scatter Blocks
- various mounting hardware
Also check out the smaller London 10 package designed for 100 square foot rooms.
2. Auralex Roominators Pro Plus Kit
The only brand more popular and trusted than Primacoustic…
Is of course…Auralex.
And the standard full package option they recommend for project studios is…
The Auralex Roominators Pro Plus Kit.
Include in this kit is:
- 36 Studiofoam 2″ Wedge Panels
- 12 LENRD Bass Trap
- 8 T’Fusor 3D Sound Diffusors
- EZ Stick Pro Adhesive Tabs for mounting
Also check out the smaller, more affordable Auralex Alpha-DST Roominators Kit containing:
- 32 1’x1′ two fin panels
- 32 1’x1′ four fin panels
- 4 LENRD Bass Traps
- EZ Stick Pro Adhesive Tabs for mounting
Up last, the best package of them all…
3. Auralex SFS-184 SonoFlat System
For those of you who don’t care much for the “traditional” look of acoustic foam…
Auralex also offers some sleek and sexy alternatives in the Auralex Sonoflat Series.
At the top of this series, is the Auralex SFS-184 System, which offers the MOST goodies of any package we’ve seen so far.
Included in this package are:
- Thirty-Two 2′ x 2′ x 2″ SonoFlat Panels
- Eight SonoCollars
- Eight 12″ x 6″ x 28″ SonoColumns
- Six Q’Fusors
- Tubetak Pro for mounting
Also check out the cheaper Auralex SFS-112 SonoFlat System which includes:
- Twenty-Four 2′ x 2′ x 2″ Sonoflat Panels
- Four SonoCollars
- Four 12″ x 6″ x 28″ SonoColumns
- Tubetak Pro for Mounting
The 3 KEY Points in Any Room
Once your acoustic treatment has arrived in the mail, you’re almost ready to start putting it up.
First though, there 3 key areas of the which we must define.
- Trihedral corners – shown in the diagram as the red dots
- Dihedral corners – shown in the diagram as the blue lines
- The Walls – shown as the flat white surface area
Common wisdom states that in any room:
- the trihedral corners get first priority for coverage
- the dihedral corners get next priority
- the walls get last priority
And here’s why:
For best results, it makes sense to place acoustic treatment in the areas which have the greatest impact, right?
Well at the trihedral corners…all 3 sets of parallel walls converge, and any absorption located here catches room modes from all 3 dimensions, essentially working 3x as effectively.
The dihedral corners get next priority, since they work on 2 dimensions. And finally there’s the walls, which only work on one.
How to Set Everything Up
The typical setup process consists of 4 basic steps which I’ll show you now.
Since bass traps offer the widest range of broadband absorption
It makes sense to put them in the areas where they can have the greatest impact.
Which is why the first step in setting up your acoustic treatment is to mount a bass trap at each of the tridhedral corners.
For more information on what else you can do here, check out to the following post:
Now that the most important corners are covered…
The next step is to fill in the remaining corners with acoustic panels.
To cover the dihedral corners, simply bend them around the edge as shown in the picture…
And be sure to leave an air gap for maximum low-end absorption.
While I recommend using some of your acoustic panels for this purpose, don’t use them all…
Because you still need most of them for the next task…
Whenever two opposing walls are parallel to each other…
Sound waves have a tendency to reflect back and forth in the same spot…
Causing some frequencies to be amplified, and others to be cancelled-out.
To avoid this problem, mount your acoustic panels flat on the walls, and be sure to spread them evenly thoughout the entire room.
To get maximum effectiveness from a limited number of panels, avoiding placing panels on BOTH points of opposing walls…and instead, stagger their positions as shown in the above picture.
The commonly accepted theory when it comes to diffusion is…it’s far more effective in larger rooms compared to smaller rooms.
Add to that, the fact that commercially-made diffusers are expensive, and it’s no surprise that most home studios skip it entirely. And that’s totally fine.
However, if you do use them… even better. In which case, the standard locations to put them are:
- the ceiling/the upper portion of the walls in rooms with high ceilings.
Everything head-level or below should be absorption to kill those initial reflections.
Control Room vs Live Room Strategies
In pro studios, where control rooms are used for mixing and live rooms are used for recording…different acoustic treatment strategies exist for each purpose.
The strategies we just covered are what you would typically use for a live room, to get a nice sound from virtually anywhere in the room.
However, in the control room, where the main goal is to maximize the accuracy of your studio monitors from the seated mixing position…
Specific acoustic treatment strategies exist, which I reveal in this post:
If your studio (like most home studios), is one that uses one room as both the control room AND live room…
Your acoustic treatment setup will need to blend elements from both strategies into a single “hybrid” plan.
What to Do if the Money’s Already Spent
When setting a budget your studio, you should ideally set-aside a BIG chunk of the money (possibly as high as 50%), for acoustic treatment alone.
The problem is…most of us don’t figure this out until after the money has already been spent.
And while you can always save up more for the future, there’s still the problem of what to do right now.
Typically, people try various DIY methods of acoustic treatment including:
- Cup holders
- Egg Crate Foam
The problem is…they DON’T work, and can actually worsen the situation by absorbing the high-frequencies, while ignoring the low-frequencies (where the real problems exist).
So here 5 effective DIY solutions that I suggest trying instead:
In rooms with poor acoustics…
The close-miking is one technique you can use to get decent sound from a less-than-ideal situation.
Here’s how it works:
By positioning the mic as close to the instrument as you can (without ruining the tone)…
You increase the portion of direct sound from the instrument, while decreasing the portion of reflected sound from the room…thus minimizing the impact of the acoustics on the recording.
To take this concept one step further, you can also try…
2. Using dynamic mics
Since dynamic mics are typically “less-sensitive” than condenser mics…
They also tend to pick up less ambience, which is good in rooms with poor acoustics.
Which is why, in untreated rooms, you should use dynamic mics whenever possible…especially on vocals, where the difference is often enormous.
You won’t get the sparkling highs of a condenser mic, but it will still sound much better overall.
3. Household Absorbers
While acoustic foam manufacturers would prefer you believe that theirs is the only material that works…
It simply isn’t true.
Because really, any type of soft porous material such as pillows, blankets, couches, or even clothes, can offer similar absorption.
And since you already have plenty of that stuff lying around your house, it won’t cost a dime to simply store some of it in your studio.
While it might not look as professional as “real” acoustic treatment, it does help a lot…as long as you remember to stack everything as thick as possible, so all frequencies absorb evenly.
4. The “Mattress Vocal Booth”
Even better than pillows and blankets…
Often times, the best natural sound absorber in your house is a mattress.
Which is why the most popular DIY method of recording vocals is to prop an old mattress against your wall so its directly behind the singers back as he performs.
Remember though, that making this technique work requires effective broadband absorption. And to do that:
- You MUST use a heavy solid-core mattress, and NOT a light inner-spring mattress.
- The most sensitive side of the mic should face TOWARD the mattress, to shield it from incoming reflections.
5. Reflection Filters
If commercial acoustic foam is currently beyond your budget…
But you think mattress and blankets are a little bit too ghetto…
A great “in-between” solution many project studios use is a reflection filter.
Rather than the absorbing reflections scattered about the room, reflection filters work by absorbing them before they even enter the room…
Using a semi-circle absorption panel which mounts to your mic stand and wraps neatly around the mic.
And while they may not work quite as well as proper acoustic treatment…
- they still work decently.
- there’s virtually no set up.
- they’re about 1/10th the cost of a stand room package.
Even though they make not work as well as “proper acoustic treatment”…
By using your reflection filter in combination with the previous 4 techniques we covered, your recordings will sound 1000x better than they otherwise would in a completely bare room.
And they’re a great temporary solution until you can afford something better. To see which ones I recommend, check out this post: