As you’ve heard countless times, your room plays an important role in how good your recordings are going to sound.

Got a bad-sounding room? Your recordings will sound bad.

Got a bad-sounding room? Your mixes will sound bad.

You can certainly do lots of things to combat a bad-sounding room, and no room is perfect, but what if your room was destined to sound bad? What if the mere dimensions of the room were all it takes to make a room unfit for studio work?

The Problem With Rooms

In a perfect world, we would be able to record and mix in a completely open space, where no reflections could swoop in and mess up the sound. If sound travelled through outer space, that would be an IDEAL place to mix a record…but it doesn’t, so we’re stuck figuring this out on earth.

The second-best option would be to mix outside, in a nice open field perhaps. Between the mooing cows, the wind, and the potential rain, you won’t get much done.

So we’re stuck mixing in a room. Whether your room is a tiny little bedroom or a big finished basement (or even a really expensive professional control room), you will have issues. All rooms (just like people) have issues.

Why? Because the sound is bouncing around the room. It’s an enclosed space, and these sound waves need somewhere to go. Since they can’t escape, they bounce around the room in all sorts of weird ways. Side to side. Up and down. Some of them make a loop around the corners of the room. It would be awesome if we could SEE them.

As these sounds are bouncing around the room, they inevitable “run into” each other. Do you remember what happens when similar sound waves combine together? That’s right, bad things. ๐Ÿ™‚

If your friend, Mr. 150 Hz is bouncing around the room, and he meets up with another 150 Hz wave, one of several things can happen. If they’re aligned with each other perfectly, you’ll get a big ol’ boost at 150 Hz. If they’re out of phase with each other, you’ll get a big ol’ cut at 150 Hz. And any other combination can cause boosts and cuts at all sorts of frequencies. The result? It’s like you slapped a graphic EQ across your speakers and asked a two-year-old to play with the EQ sliders for a while.

Your room is acting like an EQ. It’s changing the signal before it ever hits your ears. Poor signal…it never stood a chance.

While it’s much more complicated than the way my small brain can explain to you, that’s essential what happens. When sound waves are allowed to run rampant, they interact with each other and cause problems.

The Solution

The solution to this problem of sound waves run amuck is to absorb them. By absorbing the waves, they have less of a chance to bounce around the room, minimizing how much the room affects the sound.

Unfortunately, a little piece of foam doesn’t help that much when it comes to absorbing low frequencies, like our friend Mr. 150 Hz. That’s why you’ll hear people stress that you need bass traps. You need something bigger to absorb those bigger sound waves.

How low should your absorption go? It depends on the room. The dimensions of your room will tell you which frequencies will be the most troublesome, then focus on getting treatment that will absorb down to those frequencies.

Choosing the Right Room

If you have the luxury of choosing which room in your home will house your studio, you need to give it some serious thought. We bought our house a year and a half ago, and my studio is now in its THIRD location. Yep. We’ve moved it three times. As it turns out, I think this is the best-sounding room. Why? Because it has good dimensions.

I mentioned earlier that the dimensions of your room determine what frequencies will give you the most problems. For example, if one of the dimensions of my room is around 14′, then I will have issues at 80 Hz. (Just divide the speed of sound by the wavelength. 1130 / 14 = 80.)That’s because 14′ corresponds with the wavelength of an 80 Hz wave.

You can see how it can get really complicated.

Here’s where I’m going with this, and a really simple way to practically apply all this when you’re choosing your studio. You want to set yourself up to succeed. So before you start hanging acoustic treatment, you need to make sure your room isn’t fighting against you unnecessarily.

Here are two room dimension:

5′ x 7′ x 9′

6′ x 8′ x 8′

Which room do you think would be better for your studio? I’ll be honest, I used to think the bigger the better, so I’d go with the second one, but as it turns out, the 5′ x 7′ x 9′ room is MUCH better acoustically.

Here’s why. When choosing a room, you want to avoid dimensions that are divisible by the same number or each other.

In this example, the numbers 5,7, and 9 aren’t divisible by the same number OR each other. This is ideal. That means you’ll realistically only have three main trouble frequencies, rather than dozens.

The numbers, 6, 8, and 8 are ALL divisible by 2. And the numbers 8 and 8 are both divisible by 2, 4, AND 8. That’s not good. That means that whatever frequency has a wavelength of 8 feet (140 Hz) will be exponentially more problematic. Not only that, but multiples of that frequency will cause big problems. So 35 Hz, 70 Hz, 280 Hz, 560 Hz…all of these (and lots more) cause all sorts of problems.

The best solution? Simply use the other room. You will, of course, still need acoustic treatment, but the treatment will be much more effective, and the room will sound MUCH better than the other one, all because of the silly physics of the way sound travels and interacts with itself.

Your Next Step

I hope this article has helped you realize how important the room is to your recording success. If you want to learn more, and get really in-depth, practical advice for how to get the most out of your room, then go check out Understanding Your Room. I partnered up with Gavin Haverstick, who knows infinitely more about this stuff than I do, to bring you a phenomenal set of tutorial videos that will help your studio TREMENDOUSLY.

Go check it out now. The price is going up at the end of October. Here’s the link.

  • Hi Joe,
    First off, great site, with lots off very useful information! The following is not intended to downgrade that quality rating, I’m just being piccy….

    Your above article sparked interest regarding my own recording room. Wherein I “Googled” room acoustics to find more info on the subject.

    What I did notice, which relates to your article, is that the actual formula for finding problem frequencies in a room is: 1130/(dx2)=hz and not as you state 1130 / d = hz. I believe the reason for this is that the problem arises on the sound waves return journey not it’s outward journey.
    This does not, of course, negate your results, it simply pushes them up a multiple. 1st problem in a 14′ room would be at ‘around’ 40hz, 2nd would be 80hz.

    Keep up the good work,
    Regards,
    Ted

    • Gotcha. I got that formula from a professional acoustician…I trust him a LITTLE bit more than Google. ๐Ÿ˜‰

    • Antonio Freitas

      I have done a lot of research on this subject, and it appears that there is a lot of mixed-up stuff regarding the formula for “standing waves”. The formula that Joe got provides the basic wave length for that dimension of the room. The formula put forward by Ted gives the very lowest mode (standing wave). Once you multiply this by 2 then we get the next nasty wave (Joe’s formula).
      For anyone interested on this subject, and wanting to improve their dimensions, I recommend some sites with good info and also some great calculators.
      The first site is:
      http://www.marktaw.com/recording/Acoustics/AcousticsCrashCourse1-Mod.html
      His formula

      (Speed of Sound / 2)
      Frequency = ———————-
      Dimension of Room

      is the same as Ted’s (below), but only looks different.

      Speed of Sound
      Frequency = —————-
      (Dimension x 2)

      The second site is:
      http://www.bobgolds.com/Mode/RoomModes.htm
      This calculator, along with the standing waves (modes), also gives back great visual feedback on how close the frequencies are bundled together (a big no-no if too many pile up, especially the AXIAL type).

      The third site is awesome for room dimensions:
      http://forum.studiotips.com/viewtopic.php?f=6&t=684

      The fourth site is VERY INTERESTING. Look it up!
      http://web.archive.org/web/20010803052829/http://www.headphone.com/EditorialHeadroom/RoomTubes.asp

      This fifth and last site provides critical information regarding the absorption qualities of different materials. This is extremely important for all of us that want to spend our money wisely.
      http://www.bobgolds.com/AbsorptionCoefficients.htm

      If anyone is interested on further pursuit of optimizing their room dimensions, especially if the room you have has two or more dimensions that are very close, I would recommend looking for “3 prime numbers” that are not near each other nor being multiples of each other and build a heavy screwed together partition, as I have done in my place.
      Presently I am in the process of deciding on the measurements for resizing my studio. My plans are to add another inner wall at the back of the length (mini closet with super-duper doors). Redo/move the partition-wall that separates the main room from the other two booths. Additionally, I will redo the wall-partition that divides the two booths to create two different sounds. In the end I will be using a generous amount of 2″ and 4″ foiled 703 fiberglass and or rockwool board.

      I hope this information will help those that want to grow in knowledge.

      • Antonio

        It appears that the uploading process screwed-up my formulas. I am going to try and write them differently

        Frequency = (Spd Sound /2) / (Room Dimension)

        is the same as Tedโ€™s (below), but only looks different.

        Frequency = (Spd Sound) / (Dimension x 2)

        The speed of sound varies tremendously with the materials it is being transmitted on. But for all purposes, as Joe has mentioned it, use 1130 ft/second or 344 meters/second (unless your studio is at a very high altitude).
        Remember that there are 3 “THREE” dimensions for every rectangular room, unless it is a weird shape. If your room has two or more dimensions that are very close, or the same, that is very bad for modes.
        Good luck building a full wall partition. It can be very useful for embedding some or all of the studio equipment, thus removing it from the room. It can also work as a unique Bass-Trap if it is designed properly.

  • Izzy

    I was under the impression that the speed of sound is different in high pitched and low pitched sounds. And whether or not its dry or humid. how would you quantify the speed of sound in this case to optimize the room acoustics? Is it a case of resonance?

    • I just use the generally accepted speed of sound. It varies based on humidity and altitude, but I’m not sure that it varies from high to low frequencies. Either way, it’s not a super-scientific approach, but it gives you a good idea of what frequencies to watch out for.

  • Chris House

    Joe now when you’re talking about the dimensions of a room are you talking about a square shaped room, can this case work with a celling triangular shaped or any room not square shaped???

    • Hey Chris, yeah I’m talking about rectangular rooms. Once you get into other shapes, it’s not nearly as predictable unfortunately.

      • CameronN

        ย That sucks . . . my ceiling is at an angle to my floor. The room seems to sound pretty good though.

  • Cush

    It can become confusing but you need only arm yourself with a couple of things. 1- calculator, 2 – pen & pad, ask Joe.

  • Rasmus

    Out of curiosity, how many decimals would you add to the dimensions of the room? And would something like a warderobe covering an entire wall count as an “extra” wall, changing my dimensions? With the warderobe I think I’d have 4m x 3,5m x 2,5m, which should be fairly alright (altough 3,5 could be rounded to 4 and thus give me problems? The room is almost square, which is too bad).

    • I’m not entirely sure, but I tend to just measure the room, then try to use the furniture in the room to help with absorption/diffusion if possible.

  • My almost square mixing room has a problem, even after room treatment (as recommended by auralex room analysis) 2 bass traps in each corner, mid range foam on both sides.

    I get this dip in low range, below 100 hz at my mixing chair, which is almost in center of the room. To check out the bass, i actually have to stand three feet behind my mixing chair, back to wall, and then i hear the kick drum and bass gtr thump.

    Another thought is, maybe what i hear at my mixing position is the accurate repreaentaion of the bass freqs, and maybe standing by the back of the room is an inaccurate representation , ie exagerrated bass freqs.

    Any thoughts Joe ? Love the info on ur website and blog btw

    Yamaha hs80 ‘s with hs10 subwoofer.

    • A square room isn’t ideal. Being in the center of a square room isn’t ideal either. You want to be somewhere around the 1/3 area for a more accurate “spot” to put your head. Around the corners of a room are generally much more bass heavy, since that’s where the low frequencies build up.

      Honestly, you may not need that subwoofer. It’s just introducing more low end into an already-problematic room. The 8’s give you plenty of bass to mix with…just my opinion. Worth trying.

  • jems

    I moved appartment and my “studio” was reduced in size to about one third. The bass practically dissapeared from my tracks and mid range sounds became bloated and unclear. From what I read on realtraps site, the best way to go with small rooms is to absord as much as possible, especially with bass frequencies. But what about frequencies above 250hz, can u absord too much? Will diffussion work in a very small room (I think its around 6m2)?

  • A good basic starting point, Joe. Well done!

    Further reading can also be found with any of Dr. Floyd Toole’s white papers concerning Small Room Acoustics. Also, there are free programs that allow you to calculate Room Modes and thus plan out diffusion/absorption.

  • Joe,
    I’m just now starting to deal w/ all of this stuff. The room dimension thing is a new concept for me and thankfully my room is “ideal” as in example 1 that you gave. Question: I’ve seen by your setup regarding acoustic treatment, that you tend to put your desk in front of a window. It doesn’t appear that you’re using any treatment in the window. Is this correct? Are you only treating the walls directly behind the monitors? Why does a window not need treatment?
    Thanks in advance!
    David

    • Answer: If the window got treatment, I would go crazy. ๐Ÿ™‚

      I need to see the outdoors. I wouldn’t do well in a window-less man cave. And it’s important acoustically to set up in the shortest wall in the room, so I end up having only ONE place to put my desk. I treat the wall around the window some, but in all honestly, my computer monitor/iMac block most reflections from the window ANYWAY, so while I’m sure it would be ideal to treat everything behind the speakers, I don’t think it’s a deal-breaker.

      Also, you gotta keep in mind…almost any pro studio I’ve been in had a big, humongous window behind the console, letting you see what’s happening in the control room. Use treatment as much as you can, but don’t let it get in the way of function…or sanity for that matter. ๐Ÿ™‚

    • Antonio Freitas

      In my studio I only have windows in-between the rooms and I don’t go insane, but I had to remove all the windows. Trucks drive by my place at a distance of about 150′ while applying their Jake brakes (those very noisy ones that use the engine to help slow down the truck). The isolation that I did to my place in the 90’s prevents that very loud noise of being heard in the inner rooms.
      Another thing I do is I lay my monitor down on an angle. My large monitor (40″) lays on an angle that resembles a large mixing console in front of me. That also minimizes another standing wall (back and front of the monitor) for the sound of the speakers to bounce around. So when I am doing some serious mixing only the speakers and I are at eye level, and most surfaces are in a way that drive all reflected sound waves away from me and into the back part of the room.
      Experiment and see if you can hear a difference. In my case it was enormous. Everything became a lot clearer.

  • Timely advice for me!

    • No kidding, dude. Do you off-hand know what the dimensions are of the rooms you’ve got available?

  • Gary

    hi
    Iยดm from Peru and I always read your articles. I have one doubt … Since meters are mostly used in my country… how many meters is 1′ ( I’ve never seen this unit of measurement) ?

    • Great question, Gary. 1′ is one foot, which is roughly 1/3 of a meter. It doesn’t really matter what the unit of measurement is, though. a 4m x 5m x 3m room would be much better than a 2.5m x 2.5m x 5m room…for example.

      • Gary

        thanks Joe and greetings from Peru
        ๐Ÿ˜€

    • Antonio Freitas

      Welcome to the ancient English measurement. For all basic purposes one meter is only slightly longer than one yard which is 3 feet (3′). But for better reference use 1″ (inch) = 2.54cm. Each foot has 12 inches (1′ = 12″) and 1 yrd = 3′. This gets even better when you jump to miles (not nautical miles) which have 1760 yards, or roughly 1.6Km