DIY Voiceover Booth Construction: Acoustical Considerations

While this is a how to series of sorts, I am not responsible for any injury, destruction, or loss of any kind including monetary that you may incur while attempting anything inspired by what you see here. By continuing to read this vlog and watch the associated videos you assume all responsibilities for your decisions and actions. I am not an audio engineer, nor a carpenter. Hopefully you can learn from my research and mistakes. When my design is inspired by someone else’s design it will be noted in the description.

Sound Proofing

Sound proofing is a very expensive, time consuming process where you isolate a space entirely from outside noise. If this is what you need, you are in the wrong place. My DIY series does not explain this. Sound is a sneaky thing! It has the ability to pass through almost anything! To achieve a truly sound proofed space you basically need to dynamite a nook in the side of a mountain and build what could double as a bomb shelter. If you don’t have the time and money for this, read my blog.

Sound Insulating

When someone other than an audio engineer uses the term sound proofing they are often thinking of sound insulating - which is a more realistic goal for people like you and I. If you are building a relatively small audio booth, you are insulating a space from outside noise - as much as your budget allows. A little noise sneaks into the space, but if you set up the space right and utilize the dynamics of your microphone, not much of it will enter into your recording. If you want to insulate an entire room or closet, there are other bloggers who do an excellent job explaining this. It will involve adding insulation in the existing walls and and couple layers of drywall.

Sound Absorption

Sound absorption is achieved by using dense materials that slow down and dissipates the sound energy as it moves through the material. Well-insulated walls absorb the sound so that very little of it enters the booth or studio.

Diffusion panels absorb and dissipate the sound energy of your voice so that it doesn’t reflect off the walls and back into your microphone.

Bass or Low frequency sounds bounce around in the space and tend to accumulate in corners causing hum in your recording. Well-placed bass traps absorb and dissipate these frequencies so that you have a nice clean recording with a low noise floor.

You are now armed with the knowledge you need to assess the effectiveness of various DIY ideas you’ll find on the web.

Egg crates? Thick? No. Dense? No. So, just no. Due to the contour of the surface it might scatter the sound as it reflects it, but is this one of your goals? It might be in a mixing room, but even then, if you need to scatter sound there are better ways.

Just say no,

to egg crate & synthetic carpets.

The egg crate foam you can get at a fabric store? It might scatter the reflection a bit, but do you think it’s thick and dense enough to absorb much energy? Nah.

What about carpet? Does the carpet have a dense layer of material of substantial thickness that sound could get caught in? If not, don’t use it. Synthetic low shag carpet is a “no”. Thick braided cotton rugs are great.

Braided Cotton Rugs

Thick braided cotton rugs are a great solution for the floor or hung on the walls. Shout out to voiceover artist and coach Marc Cashman for this suggestion. Marc credits Tim Tippetts with the idea.

What about an old comforter? That would do a better job of knocking down reflections than synthetic low shag carpet, but the batting may not be dense enough to absorb much sound energy.

The Best Solution for Sound Diffusion is: 100% Cotton Felt Moving Blankets

I tried every solution and the best, hands down, is 100% cotton felt moving blankets. Many moving blankets are a blend and work pretty well.

My favorite for diffusion: Uhaul 100% Cotton Denim Felt Moving Blankets. Check out this blog post to see how I integrated them into my booth.

These moving blankets can be hung on curtain rods or stapled to the wall. My voiceover booth is covered in 3 layers of moving blankets. After the first layer, I used some smaller pieces of moving blankets over pieces of roxul safe n sound to diffuse the sound to the right, left and above my head. Then covered in 2 more layers of moving blankets.

The best solution for Sound Absorption is: Roxul insulation and Mass Loaded Vinyl

Insulation

Roxul insulation makes for good sound insulation and diffusion. When using for diffusion panels I recommend covering in furniture batting to keep the particles from escaping and then cover in burlap!

I’ve used the following three kinds of insulation with good results:

Roxul SL 960 - dense rigid and lightweight(more expensive than the other options)
Roxul Comfortboard 80 - dense rigid insulation
Roxul Safe n’ Sound - less dense, not rigid, requires thicker sheets

See how I incorporated these insulations into the production of diffusion panels and bass traps in my this blog post.

Check out this website for good prices on sound absorption and proofing materials.

https://www.tmsoundproofing.com/

Sound Absorption and Sound Diffusion on a Budget for DIY Voice Over Booth