Acoustic Treatment Topics:
» I just have a project studio; do I really need treatment?
» Absorption, diffusion and bass traps: the three acoustic amigos.
» How much acoustic treatment should I use?
» Where do I hang acoustic treatment it in my room?
» How do I hang it on the wall?
» Help me soundproof my room!

You've handpicked every piece of gear in you studio, but you're still not happy with the end result. Most likely, you've overlooked one of the most crucial aspects of recording - the acoustics of the room. Every sound that occurs in the studio will come into contact with a surface and either be absorbed or bounced back. From early reflections to bass modes, the lack of acoustic treatment can really color your recordings, and not usually in a good way. That's why we've put together this acoustic treatment buying guide to show you the basics to make your space sound better. But since no two rooms are exactly alike, you can call 1-800-222-4700 and talk to your Sales Engineer about customized treatment options for your studio. We'd like to thank our friends at Auralex, the experts on room acoustics, for providing much of the information that follows. For an in-depth look at the construction of an acoustically accurate space, download Auralex's Acoustics 101.

I just have a project studio; do I really need treatment?

Absolutely! In fact, because your project studio is likely in a room that was not initially designed or tuned to be a comfortable listening or tracking environment (spare bedroom, basement, attic, etc.), affordable acoustic treatment is exactly what you need.

Did you know that your room already has a sound all its own? As you know, sound travels. While traveling, it is affected by the path it's on: it might get reflected, absorbed, or both based on a number of factors. All the sound in your room is also interacting with other sounds that are traveling (or intersecting) along its path, which further affects the sound of your room. Think of it this way: if we could add visual color to the frequencies of sound traveling in a room, we would be amazed at the direction, reflections and kaleidoscope of movement of sound. Without getting too deep into physics, all this sound traveling around in your room (especially rooms with parallel walls!) creates sonic anomalies that did not exist in the original sound.

One of the keys to being able to accurately monitor a recording, or to getting good, clean sound on tape or hard disk in the first place, is removing the sound of the room from the equation, or at least controlling it. Why? You really want to hear (and record for that matter) only the source, and NOT what's bouncing off your walls. Acoustic treatment is the best way you can be sure that what you're mixing, editing, composing, etc. is accurate, and not overly affected by the room you're sitting in. Even if you want to have a "live" sound in your recordings, you still want to have control over how much liveliness exists in your room. Acoustically treating your room will allow you to control how sound travels in your project studio giving you the ability to accurately record and monitor your music and other source material.

There's an added benefit to treating your room. It makes your environment more comfortable to be in, so you'll find yourself being more productive, at ease, and creative, and in general, reaping more enjoyment out of the space. Most folks report improved concentration and hearing acuity in well-treated spaces.

Absorption, diffusion and bass traps: the three acoustic amigos.

How can absorption help my studio?

Acoustical foam is well suited to alleviate flutter echo and slap, the two most common problems in rooms not specifically designed for music recording and performance such as your spare bedroom, basement, or garage (go into a very open room and clap your hands – this resulting sound is very bad for recording or mixing). Foam is easy to work with, simple to trim to size and cost-effective for virtually any budget. Foam will improve the sound picked up by your microphones and give you a more accurate monitoring environment, thus ensuring your recordings will sound better (“translate”) wherever they’re played. In a monitoring environment, foam allows you to hear recorded works the way the artist intended without your room detrimentally modifying the sound.
Click here to view all absorption products

How can diffusion help my studio?

Diffusion keeps sound waves from grouping, so there are relatively few, or no “hot spots” in a room. Diffusion disrupts standing waves and flutter echoes without simply removing acoustic energy from the space or greatly changing the frequency content of the sound. Diffusion can make a small space seem large and a large space seem even larger. The proper balance of diffusive and absorptive surfaces varies with room size, function and desired results.
Click here to view all absorption products

How can bass traps help my studio?

Low-frequency sound waves are so long - and thus so strong - that they are the toughest to control. This is true no matter whether you’re attempting to block their transmission to a neighboring space or trying to absorb them to clean up the low-frequency response within a room. Controlling low-frequency sound is harder than controlling mid- or high-frequency sound and generally requires more effort and expense. What’s more, low frequencies LOVE to hang out and cause us a lot of problems in corners, boosting the apparent amount of bass in our rooms by 9dB and making us think we have 3 times as much bass as we actually do. So, corner bass trapping is absolutely vital to smoothing out any room’s sound. You may dig the way your favorite track “thumps” the kick and bass guitar in your living room, but in your control room, you need to hear the low frequencies for what they truly are.
Click here to view all bass trap products

How much acoustic treatment should I use?

Most rooms usually fall in the 25% to 75% range for coverage. And this is only for walls and ceiling. This largely depends on the room design, your intentions for the room, and maybe even your style of music or content.

We checked in with Auralex (the acoustic treatment know-it-alls), and they suggest the following generalizations:

Would you like some help figuring out how much acoustic treatment you should place in your room? Simply download the Auralex Personalized Room Consultation Form, fax it in to Sweetwater and let us help you figure it out.

Where do I hang acoustic treatment it in my room?

Just where to hang your treatment is both an art and a science, and it’s still subjective based on your desired goals, room function, and room design. It’s truly your call, but bear in mind that once bad “room sound” is captured on tape, disk, etc. you can never get rid of it. Similarly speaking, once you’ve mixed that CD in a non-treated room, it is, well, what it is. In the end, while the following are general ideas to help you get started, please call your Sweetwater Sales Engineer who can help you walk through the process of just where to hang your acoustic treatment.

Mixing Area:
Many studio designers will tell you that the front of the room (walls and ceiling) should be treated with absorption of some sort, perhaps as far back as the engineer. The ceiling from the engineer back can contain a mix of diffusion and absorption, but many top designers feel the rear wall should feature a diffuser array surrounded by broad-bandwidth absorption, especially in larger rooms. The sidewalls and ceiling from the engineer’s position on back can be alternately absorptive and diffusive. If your budget is limited, just about everyone agrees that treatment around your mixing area should be the priority over the rest of the room. This will give you a tight listening area that is controlled, allowing you to hear the subtle differences in the various frequencies of the mix. Again, you’re just trying to take the room out of the mix, and bring the content (music, voice over, etc.) forward.

Recording Area:
If you’re building an isolation booth (or tracking area in your project studio room), you might consider a completely absorptive environment, starting from the top of the wall down to about knee-height (or further if you prefer). This will allow you to control sonic variables of the recording in the mix (by adding reverb, EQ, etc.). However, this is extremely subjective. Other performers feel “trapped” by a booth that is completely dead, so you might consider adding some diffusion (and some form of LF control is ALWAYS a good idea). This is also largely dependent on the size of the room or isolation booth and the style of performance.

How do I hang it on the wall?

Believe it or not, acoustic treatment manufacturers such as Auralex have spent a great deal of time and money in the research and development of their products. As such, they have created nifty adhesives that work specifically with their products. Don’t worry; they’re incredibly easy to use, and very affordable.

	Foamtak: Foamtak is an acoustic foam spray adhesive is quite simply the fastest and easiest way to mount Auralex acoustic foam products. Unlike Tubetak Pro adhesive, which is more permanent and tougher to remove down the road, Foamtak can be applied lightly so that your foam is removable, or it can be applied heavily for a more permanent bond. Foamtak contains more actual solids than competing spray adhesives (you're getting more for your money!) and uses a unique spray pattern, so it offers greatly improved long-term bonding power vs. other sprays, which virtually ALWAYS dry out and fail. Foamtak is guaranteed not to oxidize Auralex acoustic foams.
	Tubetak Pro: Tubetak Pro is a super-strong, water-based liquid foam adhesive that comes in a tube and applies easily with a standard caulking gun. (Tubetak Pro IS suitable for air shipping.) Tubetak Pro provides a permanent bond and one tube mounts up to 32 square feet of foam or diffusers, depending on thickness. Other brands of liquid adhesive have been known to oxidize ("eat") foam, but Auralex guarantees that Tubetak and Tubetak Pro will not oxidize Auralex foam products. Tubetak and Tubetak Pro Liquid Adhesive may be purchased in any quantity needed (you don't want to use Liquid Nails brand because its manufacturer published a memo some time back advising that it not be used with acoustic foam due to possible chemical interactions that can cause the foam to disintegrate prematurely.).
	TEMP•Tabs: If you’re concerned about moving your studio around a bit, you might consider Auralex’ TEMP•Tabs. They are a temporary Studiofoam mounting solution designed for easy installation and maximum flexibility. By using TEMP•Tabs, you no longer need to commit to permanently placing your acoustic treatments or cleaning adhesive residue and chunks of your investment off of your walls. This system works remarkably well with studio foam on walls. For about $40 you get 72 “tabs” and 72 sets of “Vel-Coins” and one tube of Tubetak Pro.

Another Tip:
This may be hard to believe (though we've spent HOURS doing this very thing right here at Sweetwater), but to cut Auralex acoustic foam, simply use an electric carving knife! You can create custom designs, a super finished touch and super-smooth edges. The key is to let the knife do the work!

Help me soundproof my room!

One of the single biggest concepts to understand and appreciate is that typical acoustic foam, your grandma’s quilt and/or egg cartons from the 80s are not going to "soundproof" your room. Acoustic foam is an extremely effective absorber of ambient, reflected sound and helps make rooms "sound better,” your grandma’s quilt will serve you better on cold winter nights as, well, a quilt, and please, throw out those old egg cartons – they’re gross! Of the three, acoustic foam will contribute some sound isolating properties (mostly high frequencies), but it is not sufficient by itself to keep sound in or out of a room; that’s just not what it was designed to do.

So, let’s take a quick look at what you can do to help isolate sound in your room. Good sound isolation results from two main details: density and air gaps (or, more specifically, decoupling of structures). Density is in the form of materials such as drywall, chipboard, plywood, soundboard, vinyl barrier products (such as SheetBlok), lead, etc. Air gaps between existing and new walls should, if possible, be at least two inches wide. The combination of density and air gaps will provide varying amount of isolation depending mostly on quality of workmanship.

In a pinch, SheetBlok sandwiched between two layers of drywall offers an amazing amount of density, but even this alone won’t completely soundproof a room (though, you’d be surprised at how well it works!). We mention this only because we realize that many of you are building studios out of unfinished basements, bedrooms, rooms above the garage and the like. In such situations, floating the room (and thus creating necessary air gaps and decoupling) is unlikely, but the SheetBlok sandwich might still be a possibility.

Want to learn more? For more information on building the perfect room, download Acoustics 101, Practical Guidelines for Constructing Accurate Acoustical Spaces from Auralex (52 page, 4.3MB PDF).

For a free personalized analysis of your room, click HERE or call Sweetwater at 1-800-222-4700.