Soundproofing and acoustic treatment are important topics to tackle when setting up a home studio. Even if all of your sounds are electronic, the room you are in will strongly affect the sound you are hearing through your monitors. In this article we get to grips with the issues and some common ways of dealing with them.
A few weeks ago I asked Audiotuts+ readers for their hints and tips about soundproofing in an Open Mic. A huge thanks to everyone who responded. You'll find many of the suggestions in this article. An article like this is never finished—you can add your experiences to the comments too. Which acoustic treatment techniques did you find effective? Are there any products you would like to recommend? Did you learn some lessons the hard way that you can warn the readers about?
Bobby Owsinski's excellent Premium tutorial Build an Effective Room Treatment on the Cheap (borrowed liberally from Chapter 2 of his book “The Drum Recording Handbook” ) gives a great overview. It explains the why as well as the how, and is worth the small amount of money required to read it.
We'll start with an overview of the issues that need to be tackled.
There are a couple of times you'll most notice effective sound treatment: when using microphones, and listening to your monitors. Acoustic treatment affects what you hear, and what your microphone hears - not to mention your family and neighbors!
There are four different areas of sound treatment you may need to consider:
Soundproofing (isolation) - keeping noise out (and in). Traffic noises, dogs barking, lawnmowers and the TV are all things you don't want recorded onto your tracks. You need a way of keeping those noises out of your studio - particularly when you're using microphones. If you live near an industrial area or highway, you may find that vibrations also affect your recordings. Thirdly, if you have live instruments—or just like to play loudly through your monitors—you also need to think of your family and neighbors. You want your music to stay in the room. See below.
Eliminate noise from within the room. Equipment noise from within the room can also spoil a recording. Consider keeping your power amps and computer boxes (which fans that might be noisy) in another room. Also look for other potential sources of annoying noise. When I was first married my wife kept some birds in our office/studio. It's frustrating how often I can hear those birds on my old recordings. We won't be pursuing this topic any further in this article, but you can read more here: Home Studio - the Best You Can Get and this AudioJungle forum thread.
Acoustic Treatment. The way different frequencies are absorbed or reflected by your walls and other hard surfaces can negatively impact on the reverb and EQ that are picked up by your mics, and that you hear when listening to your monitors. See below.
Separation. If you are recording more than one instrument at a time—or singing while playing an acoustic guitar—then ideally you will want each separate instrument on its own track without too much bleed through from the other instruments. This isn't a major concern of most home studios (where instruments tend to be recorded one at a time), so we won't deal with it further in this article.
Have you ever tested the isolation of your studio? Give it a go. Firstly, sit quietly in your studio with all doors and windows closed, and take note of any outside noises you can hear. If you can hear them, so can your microphones.
Secondly, play some music through your monitors at the loudest volume you're likely to listen at, leave your studio and close the door. Wander around your house and take note of how loud the music sounds to those you live with. Turn on your TV and see if your music interferes with it. Also wander around your yard to see if it is likely to be annoying to your neighbors. If loud instruments will be played in your studio (drums in particular), have someone play them at the usual volume and conduct the same experiment.
Chances are there is more noise coming into and out of your studio than you would like. What can you do about it? The usual answer is: bulk, mass. You need lots of solid material to soak up that sound.
Any sort of sound treatment can be expensive, but it doesn't have to start there. Here are some inexpensive ideas. Also check the next section on acoustic treatment—anything you read there that involves bulk will also help with soundproofing.
Open Mic commenter Steve points out that just dressing a room with carpet, paint and furniture goes a long way. "did some homework on sound control when I built my home studio 10 years ago. One comment I came across was not to “over treat” the room. The item was specifically geared to the small project studio and the recommendation was to view the room as a whole, after you’ve “dressed” the the space: laid carpet (if going that way), final paint, and gear and furniture in place.
"The window in the west wall was 15 or 20 feet away from a sidewalk, and I didn’t want street noise leaking in, nor letting studio sound out ( so not to attract attention to the large amount of equipment). You could stand on the sidewalk and, under the cover of normal street noise, not be able to make out the source of the music, if you could even hear it."
Steve also had a living room directly above his studio, and took effective measures to stop the sound leaking upwards. "The biggest 'treatment' we took on was isolating the cliening of the studio from the living room directly above. We used a layered approach: acoustic tile, air gap, landscape cloth, air gap, Tentest (the black fibrous-like material that sheathes houses). Pink insulation then was the final layer and wrapped the joists. Very little noise transferred through the house."
You can add density to your walls by lining them with matresses or similar. Commenter "Just an Audio Major" points out, "The biggest tip I can give you for isolation is Density. The denser the materials you use for your studio the more isolation you’ll get. I’ve heard of many engineers covering their home studio walls with 4inch foam wrapped in linen cloth."
Blankets are a simpler, less expensive (possibly less permanent) option. "Just an" says, "When all else fails, use heavy blankets. Cover the walls in your mixing room with blankets. The most essential place to throw your heavy blankets is on the floor at your door seal. The air gap between your door and carpet/tile makes all the difference in how much sound is leaving and entering the room. You’re noise floor will have a dramatic decrease."
A different Adrian has a similar suggestion: "We bought quite a few duvets from a local supermarket and carpet glued them to the wall. excellent and totally soundproof." A duvet is a type of bedding similar to a blanket. In Australia we call them quilts or dooners.
"Just an" also points out the problem of having gaps say between your door and the floor. "Another huge issue in most peoples’ studios are the air gaps. Any hole the size of a pencil tip can transmit a lot of sound pressure. My recommendation would be to purchase some Acoustic Caulk and fill all the holes up in your mixing room. Definitely start at the window seals!"
All of these options have been fairly easy and inexpensive. But if you're more serious, and don't mind doing a bit of building, there is a lot more you can do. Here are some suggestions:
Jason Burns from Project K2R4 left us detailed instructions on how he constructed a home studio in his garage for less than $5,000:
"If you are speaking strictly sound isolation, I went with the build the right wall approach. My live room in my home studio is physical decoupled from the rest of the house and the control room. Two walls surround the live room. They are 2×4 construction on both sides, with two layers of 5/8 sheetrock on the outside of each wall, with rock wool insulation on both walls and no sheetrock between the walls. There is 4″ air gap between the walls. The total wall thickness is over 1′. For doors and windows I bought 1 3/4″ solid MDF doors, there are two doors between the control room and live room, the window is two 3′x6′x1/2″ tempered glass panes, the live room window is perfectly vertical with the inside window tilted a few degrees inward at the top to reduce glare.
"Now you might be saying that this is not a home studio, but it very much is. It’s in my garage, I built it myself, and spent less than $5,000 on materials. That’s basically a nice Les Paul and a Marshall Amp. The moral of the story is build it right, build it well and don’t skimp on the room. The end result is provides enough isolation that with someone playing acoustic drums in the live room, you can have a casual conversation in the control room and you can’t hear anything whatsoever inside the house or standing in the driveway a few feet from the garage door.
"If you would like to see, there are photos on my blog and I have a video on the blog giving a demo of the sound isolation between the live and control room. If you are interested in more, I would be glad to provide more info on how I did it and what books and reference materials I used for the design."
One common way of achieving excellent isolation is to build a room inside a room. Jean-Baptiste Collinet from EA2R is a furniture maker, and found an amazing and inexpensive way of achieving this:
"Few to say but that I found a nice way to have a great sound inside and quite no sound outside.
"I’m a furniture maker. I built a room within a room. The room within is 'suspended' and it 'floats' on tennis balls put on the floor within a special frame. No need to invest tons."
You can download JB's building plans here. The booth is to be created on the suspended floor.
The article Home Studio - The Best You Can Get? has a similar suspended floor idea, but instead of using tennis balls, uses super balls cut in half.
3. Acoustic Treatment
The way different frequencies are absorbed or reflected by the surfaces in your studio can affect the EQ and cause unwanted/unpleasant reverb. Treating this problem also requires bulk—but less bulk and more fiddling. Here are some great suggestions of how to get started, many of them quite inexpensive:
- Your studio should be carpeted. If not, buy a rug that fills most of the floor space.
- Heavy curtains or blinds should cover all of the glass in the windows.
- Install bookshelves and fill them with books. This will absorb a lot of sound.
- For a more temporary solution, consider taping blankets to the walls. czx_4 comments: "A lot of carpets, blankets and pillows on the floor and along the walls above the level of the microphone"
- Choose a room with a low ceiling. Alternatively, stretch hessian of simple sheeting across the room at a convenient height. If you're willing to spend some money, hang acoustic compensators from the ceiling.
- Even your desk can be a problem. Open Mic commenter Matty shared a suggestion that worked for him. "This sounds nuts to a lot of people but anyone who’s been in my studio is amazed… I stapled/glued acoustic foam to the cavity under my table/desk where i have mic stands, mixers computer etc. It eliminated so much static noise from the vibrations it was nuts! I only did it because i had some spare foam left over too. :D "
- Jonah Guelzo's Premium video shows you how to build inexpensive but professional acoustical panels. He suggestions you hang them on the walls at the point of first reflection, and demonstrates how to do that in the video.
- JohnnieTech has a similar solution: "I used Roxul AFB Mineral Wool encased in a 1×4 frame and speaker fabric for the wall treatments. I had to build quite a few as the room had all hard surfaces including a wood floor. I used an area rug that covers about 80% of the floor. It’s not acoustically perfect but it has made for a better listening space for mixes. The next project is to use the same Roxul AFB and cut it into triangles and stack it to fill the corners for bass traps."
- Moving slightly more up-market, Chris suggests, "We did our home theater and used Acoustiblok. it is similar to mass loaded vinyl, but works differently by changing the sound energy to thermal energy. One thing I like about Acoustiblok is that it may very well be the last American made product out there."
- If you are interested in learning more about the sort of products you can purchase for acoustic treatment and how to use them (with many helpful photos), check out Mo Volans' excellent tut Beginner’s Guide to Acoustic Treatment. He discusses room shapes and angles, finding the optimum listening position, broadband absorption tiles, diffuser panels, bass traps, and "decoupling" by placing dense platforms under your subs and speakers.
4. Further Reading
As long as this article is, it hasn't covered everything, or looked at anything in much depth. You may find yourself hungry for more. Here are some Audiotuts+ tutorials to check out:
Beginner’s Guide to Acoustic Treatment
After touching on the critical subject of acoustics and room treatment in a few recent tutorials, I felt it was fitting to create a basic guide to acoustically treating your work space. I get asked about this subject a lot so I’m hoping a run down of the essential technique and kit needed will be of some help to readers.
How to Record Vocals in a Bedroom
Recording vocals can be one of the more challenging tracking phase processes you may run into. If it wasn’t enough of a tough cookie in the studio, you can be sure it’s a daunting task in a bedroom (or a home office or any other room you’ve set aside for recording fun that wasn’t purpose-built for it).
The sad truth is that you can’t get pro quality vocals happening at home. But you can improve the sound by a mile if you’re armed with a few tricks and tips, and that’s what I intend to give you.
Build an Effective Room Treatment on the Cheap – Audio Premium Birthday Bonus!
In this special Birthday Bonus tutorial, Bobby Owsinski teaches us how to treat a room acoustically without breaking the bank.
DIY Professional Acoustical Panels – Audio Premium
Renovating your studio over the holidays? In this week’s Audio Premium content, Jonah Guelzo shows you how to make inexpensive acoustical panels for your studio wall. Check out the video preview after the break.
And here are some other great sources of information: