When it comes to acoustic treatment for your home studio, one thing I’ve learned is to keep things simple.
Acoustic treatment in your home studio is a topic that is widely discussed (and argued) on countless websites, forums, and recording blogs. With all the information out there, it’s easy to get confused. One thing I’ve learned from recording and mixing in my own studio, doing research on the Internet and elsewhere, and reading numerous articles, is to keep things simple.
I’ve read a lot of the technical articles explaining the science behind acoustic treatment and how it all works, and I find myself overloaded with information. The truth is, if you’ve set up a DIY studio, you are most likely inside a bedroom, a garage, a basement, or whatever space inside your house or shed you could find to set up your equipment. These spaces are designed for everyday living and storage and typically have parallel walls with highly reflective surfaces, which is not ideal for audio recording and mixing.
One solution that helps in converting these unfit spaces into rooms you can actually get some good results from involves adding acoustic treatment.
Before I go any further, you’ll find valid arguments and examples of how you can get great recording and mixing results with very little, if any, acoustic treatment. This may be true, but in my experience, I’ve found it’s beneficial to add at least some acoustic treatment to a room. Usually the people cranking out good mixes with no acoustic treatment are pretty seasoned, meaning they know how to “learn” a room and get past all its audio imperfections. Their ears are very experienced and trained to know how to compensate for any issues that are present in a room, and they know how to use reference tracks to determine the moves they need to make inside their rooms.
More power to them. I’m pretty seasoned, but I’m not inclined to live by this method. I prefer adding some treatment on the walls and ceiling to give me a little piece of mind when I’m starting a new project. Before I get into what kind of treatment you need, and where to put it, I want to get into the why.
Why acoustic treatment?
I don’t want to get too deep into the science of acoustics, but it helps to understand a little bit. When you are in a room with four parallel walls and highly reflective surfaces, you are going to have sound waves bouncing all over the place and colliding with each other. All this bouncing and colliding can cause some serious harmful effects and audio issues that will deceive your ears.
A main culprit is called comb filtering.
From Wikipedia: “A comb filter adds a delayed version of a signal to itself, causing constructive and destructive interference. The frequency response of a comb filter consists of a series of regularly spaced notches, giving the appearance of a comb.”
Basically, this means sound waves will bounce off the reflective surfaces, (walls, ceilings) and collide with each other at different times and spaces. So, if you’re mixing in front of your speakers, you will get the direct signal from you speakers, but the same signal will leave your speaker, hit a wall, and bounce back to your ears. These two signals could potentially (and very likely) arrive at your ears at different times. If the peaks and valleys of the sound’s original wave and the reflected wave are inverse, they can completely cancel out each other.
This means that, If you’re mixing a snare drum that was recorded with a fat tone, the two waves hitting your ear at slightly different times can make the snare sound like its thin and powerless. To compensate, you may add all kinds of EQ adjustments and plug-ins in an attempt to add beef and tone back into that snare. In reality, you were just deceived by your room. The recorded snare is still fat, but your room is lying to you!
In smaller rooms – which probably describe most home studios – bass, or low end, is a big problem area. Low end frequencies have longer waves, which means they need more room to dissipate. What tends to happen is low end frequencies will build up in the corners of your room and can wreak havoc on your perception of how much bass content your recordings and mixes contain.
To treat this issue, you can place bass traps in the corners of your room. They’re just really thick absorbers, which brings us to…
What kind of acoustic treatment is right?
There are two basic kinds of acoustic treatment: absorption and diffusion.
Absorption, like the name implies, absorbs sound and traps it. It keeps its from bouncing around the room. Diffusion lets the sound wave bounce around the room, but breaks it up. It prevents the same wave from hitting one wall, bouncing off another wall, and then colliding with the direct sound and canceling it out.
They basically solve the same problem in different ways.
I first started out with only absorption. Now I have a little of both in my studio.
Where should I put my absorbers and diffusers?
The main areas you need to put acoustic treatment are at the early reflection points near your listening position: directly to the left, right, above, below, and front of your ears.
Right now as I’m typing this, I’m in my mixing position. If I look to my left, right, and above my head, I will see some absorption panels I’ve built. If I look behind me on the back wall directly behind my head, there are diffusion panels I’ve built.
At the moment, I do not have any in front of me. I have a glass window looking into my small live room from my control room. I am in a one car garage converted into two rooms.
I have some more absorption panels (2’ x 4’) I’ve built spaced out on the walls. So there is a good mixture of bare wall, and absorption/diffusion panels.
You don’t want to completely cover your walls and kill all the acoustics. A 60:40 (treatment to bare wall) or 50:50 ratio is the place to start.
Let me be clear: my room is not perfect, but I have dramatically improved it through the use of acoustic treatment, and that’s the important part.
You can go to websites like Auralex.com or Sweetwater.com and buy some acoustic treatment packages, but outfitting your room can get expensive. If you are like me and like to do everything DIY, you can find some material at hardware or home improvement stores that might not be optimally attuned for audio mixing, but will get the job done.
For my absorbers, I built 2’ x 4’ wooden frames out of 1” x 3” cuts of wood, stuffed them with 3-inch ROXUL insulation batts from Lowes, and covered them with burlap. Then I just hung them on the walls. I also stuffed some burlap sacks with the same material and hung a few from my ceiling.
For my diffusers, I cut up a bunch of 1” x 1” boards into one-, two-, three-, and four-inch lengths and glued them to a thin board. So it’s a bunch of wood sticking out at all different lengths to break up the sound. I stole the idea from Blackbird Studios in Nashville, TN.
Another best practice is to position your console and speakers in the middle of a wall instead of tucked into a corner or nearer to one wall or another. This will get you in a symmetrical spot in your room where fewer of these issues can occur.
I’ve shot a video of my studio below showing you my panels and where I have them placed inside my studio. I hope this gives you a better understanding of where, what, and why you need acoustic treatment.
Image via ShutterStock.com.
Scott Wiggins is a touring recording artist, singer/songwriter, producer, recording/mix engineer, and music lover. Wiggins has written and recorded multiple songs which have made it into the top Ten on the TX Music Charts and has over 15 years’ experience creating, making, and sharing music. Wiggins has had the privilege of being mentored by and recording music with Grammy-nominated engineers, and his goal is to take what he’s learned and share it on The Recording Solution website and blog.
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Thanks very much for that article and video. That was more helpful to me than most articles I’ve seen.
I had no idea that there was so much to do when it comes to acoustical engineering. I figured there was a lot of things that would help with absorption, but I had no idea that there was a ways to deal with diffusion as well. These were some really great bits of advice though. I’m working on my own room right now, so the tips are going to come in handy. Thanks for sharing!