Green Glue

Get the boom out of the room

by Paul Strikwerda in Articles, Studio 21 Comments

When I decided to become a full-time voice-over artist, I made myself a promise.

I would never lose an audition because of poor audio quality.

They might not like my voice. They might not like my read, but I would not let them ditch me because I wasn’t able to deliver broadcast-ready audio. In order to get there, I needed two things:

1. A dedicated, isolated and treated recording space

2. Quality equipment 

I purposely put them in that order. You can place the best equipment in a poorly isolated and barely treated room, and you’re still going to sound like an amateur at the kitchen table. I’d rather take an affordable microphone and preamp into a (semi)-professional booth, because the end result will be much better.

So, if you’re wondering where to spend your money, buy a Studiobricks cabin, or build your own space like I did. Then we’ll talk about getting that coveted Neumann U87 Ai, okay?

I still remember the day my 7′ by 7′ recording space was finally ready. The floating studio walls consisted of multiple layers. Auralex® Mineral Fiber and Green Glue were sandwiched between several sheets of 5/8″ drywall. All the seams were caulked with SilenSeal.

Outside noise was kept at bay, but inside, the space sounded like this:

 

CHAMBER OF HORRORS

Unknowingly, I had created an echo chamber! It was an ugly beast, waiting to be tamed. Especially in small spaces with parallel walls like mine, flutter echoes can be a big problem.

The best way to kill those echoes, is to put foam or other absorbing materials on the side walls. As a rule of thumb, the smaller the space, the more acoustical treatment you’ll need. Thankfully, I had a whole bunch of Auralex® Studiofoam Wedgies left over from my previous space.

I covered parts of the wall with SoundTrax™ from NextAcoustics™ and I added four CornerBlox™ bass traps, also from NextAcoustics™. The SoundTrax™ took care of the mid- and high frequency reflections. The bass traps absorbed the lower frequencies.

If you’ve ever seen pictures of my studio, you probably know that it’s also my office. My Mac Mini, Grace Design preamp and A/D converter sit right next to me in a small cabinet. Behind me are two bookcases, and I’ve lined the backs of those cases with Sonex Mini acoustical Panels.

A DIY REFLECTION SCREEN

In spite of those panels, I felt I was still getting too much reflection from the back. I tried to remedy that by taking a room divider and placing it behind my chair. I then took an old duvet cover, a few blankets and a sleeping bag, and hung them over the divider for absorption, creating a rear reflection screen. It wasn’t pretty, but it did the trick. The boom was out of the room!

Unfortunately, my improvised contraption was heavy and unstable. It also had a life of its own. I can’t tell you how many times it decided to fall down on me, usually in the middle of a recording. Two months ago, I had had it with this thing and I started looking for a replacement.

My search lead me to GIK Acoustics, a company that is selling in the U.S. as well as in Europe. They make a wide range of high-quality acoustic panels, bass traps and diffusors.

I especially like the fact that GIK uses ECOSE® Technology in their products, a formaldehyde-free binder, based on renewable materials instead of petroleum-based chemicals. It’s used in wood based panels and glass, rock and mineral wool.

GIK makes a versatile screen panel (32″W x 72″H x 3″ thick) that seemed ideal for my booth. Audio engineers would call it a Gobo. That’s slang for a portable acoustic isolation panel. Some people believe the word “Gobo” comes from “go between.”

Being the gearhead I am, I enjoy watching these types of videos. But when I watch something that’s put together by a manufacturer, the skeptic in me always wonders: does the product actually live up to the hype? I’ll let you be the judge, because I ordered a Gobo!

First, let’s listen to something I recorded in my booth without the GIK screen panel. You might want to use your headphones for this. 

 

As you can hear, compared to the first sample, room treatment makes a huge difference. However, for me the sound wasn’t quite dry enough. You can hear a bit of reverb at the end of each sentence.  

Once the GIK panel came in, I made two modifications. I added wheels so I could easily roll the panel into position, and I added handles. That way, I wouldn’t have to touch the coffee-colored fabric while moving the panel.

Here’s me reading the same lines from my booklet “Building a Vocal Booth on a Budget,” which is available in my store. This time, the Gobo is in place. By the way, both samples were recorded in WAV-format and converted to MP3.

 

Having used the screen panel for a few weeks now, I can confirm that it absolutely delivers as promised. It’s well-made, easy to position and it comes in many colors.

REVERB ON THE ROAD 

Even though this screen panel is portable, it’s great for a studio but too big for road trips. So, what do you do when you’re fighting flutter echoes in a hotel room? Well, there’s a solution that fits into your computer. It’s a De-Verb plug-in made by SPL, which stands for Sound Performance Lab. It’s a German company.

Originally developed to shorten the sustain period for drums and guitars, I’ve found that it also works well in the vocal booth, as long as you use it wisely. Once you’ve recorded your audio, you simply select the De-Verb plug-in from the effects list. This what you’ll see:

Screen Shot 2013-04-24 at 8.22.34 PM

The left button controls the level of reverb reduction and the right one the output gain. Both can be operated with the mouse wheel. When diminishing the reverb, you also diminish the output a little bit, and that’s why it’s good to turn up the gain slightly.

Now, don’t expect this plug-in to “fix” the first bit of audio you listened to (that’s the sample I recorded before I added any treatment to my booth). It’s by no means a substitute for acoustic panels or foam. However, if you’re recording in a less than ideal setting or you like your audio “extra dry,” this will definitely add the finishing touch.

Here’s the sample I recorded without the screen panel in my studio. This time, I added a bit of De-Verb. Once again, I recommend you listen with your headphones on. You might want to start by listening to the first sample, followed by this one. That will give you a nice contrast. 

 

Perhaps you find the difference quite subtle. To me, it’s just one of those small changes that, when you add it all up, can set you apart and take your product to the next level.

But how do you know that these changes really matter? Couldn’t it just be between the ears?  

Well, in our profession everything is pretty much between the ears, isn’t it?

You’ll know you’re on the right track when nobody comments on your audio improvements, because they could not be picked up.

It comes down to this.

Bad audio is an obvious earsore.

Quality audio is blissfully inconspicuous.

Paul Strikwerda ©nethervoice