I’ve known Stephan Oberhoff for almost two decades, as a talented keyboardist and songwriter and producer/recordist, so when I saw the booth he had built in his Pasadena studio, I asked him, “What do you know about carpentry?” and he said, “Nothing before I built this, and very little since”. But there it is, fully functional and not looking half bad, even before getting a coat of paint
So here we bring you a story about the building of a vocal booth, from nothing, with no science but with a lot of ingenuity—in the hope of inspiring some of you to dare building your own, even if you too lack carpentry expertise but trust your own ingenuity. If you do know about carpentry, or if you’re hoping for step-by-step tutorials—you’re in the wrong place.
The usual disclaimers apply: We cannot guarantee success; we urge you to get help when your health or success is at risk (heavy lifting is just one of those risks); observe all safety rules; wear eye protection; and be careful with power tools.—LzR
What made you tackle this project?
Stephan Oberhoff: I had dismantled my studio before I went overseas for an extended study period, and on coming back I found a place with a remodeled garage that had drywall and tracklighting. I assembled my studio and began working on a new Melissa Manchester album (I had co-produced her previous one in my old studio in 2003), and while my co-producer (and Melissa’s husband) Kevin DeRemer and I recorded instrumental pre-production tracks, we had noises creeping into the tracks—I realized I needed a booth.
Why build your own if you’re not a carpenter?
My previous studio had a booth that an assistant built for me, so I knew roughly what could be involved. A friend of mine told me a horror story about a prefab booth he had ordered that cost a lot of money and was a debacle, so I decided to try on my own. Little did I know...
Yours isn’t square or rectangular, it looks like it was more trouble to build than others...
I decided to build it in a quasi-diamond shape for acoustic reasons. This shape largely prevents standing waves bouncing between opposite walls—I wanted to avoid what I had heard from others who had expensive rectangular or square-shaped booths and complained about boxy sound.
With the help of my good friend Jim Maher and a lot of caffeine I got through the planning stages to the trip to Home Depot for the partly pre-cut pieces. I had to rent a truck; there was a lot of weight in the 8-foot-long pieces, so if you do this, get help!
What kind of material?
MDF for the walls, floor, and roof. It stands for medium-density fiberboard and is acoustically very neutral. I had seen plywood warp and bend, which I believe to be not such an issue with MDF, but keep it dry, it hates water! Another thing about MDF—it creates a lot of dust when you work with it, so use protection!
Is it easy to work with?
It is, but you need the right blade. The sales guy sold me this 50-dollar diamond blade that was so wrong, I got nothing but dust and smoke! Then I got this 3-dollar Chinese blade that went through the material like butter—smokelessly! If you’re not sure, get a scrap piece of MDF and try the blades—if it smokes like hell, it’s the wrong one.
What was the plan for the structure?
Double walls with space in between for acoustic insulation, and also for rigidity so the booth would support itself. The roof would be the same dimension as the floor. I chose to use a pre-hung door—the core is made of particle board, the outside has some metal coating.
What came first?
The floor. It’s a double-layer of 6' x 6' MDF with that front wedge cut off. I quickly ran into trouble after putting the floor in place: It hadn’t occurred to me to check the concrete floor underneath the carpet and it turned out to be uneven and not level. I had to solve this before I could go on, or nothing would work out right down the line no matter how precisely I would cut the pieces.
What was the remedy?
I couldn’t pour new concrete or do something equally drastic, so this is how I finessed it: With 32 adjustable feet, the kind of height-adjustable sliders you see underneath fridges and such. Sounds crazy? Maybe, but I figured that, at the most, I’d only ever have 3 people in the booth, and with the weight of the booth itself that could mean well over 1000 pounds of weight. But when distributed across 32 sliders, that would work out as something like 30-odd pounds per slider—less than each of four sliders have to bear underneath a big fridge.
I inserted them in 32 mostly evenly spaced locations—once they’re inserted from below, they can be height-adjusted from above with a power screwdriver. (See the drawing on the facing page.)
In the photo you can see what the floor looked like after I inserted them all, before I laid it flat and worked with a level and a screwdriver until I had compensated for the slant of the floor and for all the unevennesses.
Did that do the job?
Yes, part of the way—the whole thing sat on carpet and kept sinking in, of course, I ended up placing rubber strips underneath, for insulation and to take stress off the threads; that did it. Then I laid a second layer and laminate flooring over the top of this base.
What came next?
The walls. MDF doesn’t come in 6' x 8' pieces, so I had to make up the walls from a 2' x 8' and a 4' x 8'. I joined them with a 1.5" x 3.5" piece into which I sank screws for good rigidity. I only used good-quality masonry screws: no nails in the entire project except for trims. This way I can disassemble the booth if I ever have to move it.
I did a lot more work on framing and so on, too much to be talking about here, and I connected the back walls with 4 L-brackets, until it stood up.
The front wall is not pre-assembled, but rather installed in pieces after the booth skeleton had been erected. First I added four horizontal crossbeams, of which the middle two would stabilize the window and act as a partial window frame. Then I added a frame to the sides of the door frame support and the angled side of the short wall. Then I fixed the outer wall to the frame and cross beams, and I noticed that the booth was starting to feel real solid—a good feeling!
Was the roof next?
Yes, and I did some more work on it. I mounted the front wall, still without the window in it, and added 2x4s on the ceiling that gave me a lot more rigidity, and will give me ample options for hanging mics. For even more acoustic separation I could install a false ceiling... maybe later.
What about the window?
Ah, the window—that’s a whole ’nother story. I was advised that a double window would do a better job if the inner pane was slanted—to avoid reflections at a 90 degree angle once again, so that the singers’ vocals wouldn’t bounce straight back at the rear of the mic. Easier said than done, of course.
How did you cut that angled groove—with a mitre box?
No, I neither knew about them nor would I have had access to one big enough. So I asked around and was assured that I would need a circular table saw; then I figured out that I could attach a guide plank on top of the piece of window frame into which I was cutting the groove. The piece of window frame (see the figure) was gradually being pulled sideways while the guide plank kept the entire contraption on track. Then I had to apply the same measurements in mirror fashion to the opposite side. It worked!
The rear window is made out of Plexiglas, which has fewer direct reflections than regular glass. Plexiglas had served me well in my previous location where I used my old booth to record a lot of records (with Brenda Russell, Melissa Manchester and others) so I stuck with it. I used silicone filler for the insulation and flexible bolstering of this window to prevent rattles after installation.
After I mounted both panes of glass and secured them, I measured extra carefully, cut the opening, and inserted the window, then I trimmed it with corner trim material to cover all the gaps between the window frame and the front wall. If I were to do it again, I would dismount the front wall to cut the hole—it would be less tricky to do, and also avoid having the sawdust go all over the insides. Anyhow, by now the door was also tight and the whole thing really looked and felt like a booth!
What came next?
Before I could go on to inner insulation and carpeting I had to do some wiring. I used a few scrap pieces of MDF to mount my old and trusted Rolls 6-channel headphone amp above a power strip.
I also mounted a vocal mic from above. This leaves the singers room to move and express themselves with their hands, and it gives the booth a tidier look. I used parts of a kick drum mic stand and a big counterweighted boom—not a standard item from the music store, but put together like that it works great and stops floor vibrations from entering the mic when singers really get into it.
How did you treat the interior?
I decided to start the inner sound treatment with a good amount of carpet padding and then covered it with some beautiful blue comforter I found at Target—it ran me about 20 bucks for each 6' x 8' piece of fabric. I covered each side wall first with the 5/8" carpet padding, then I needed excactly one sheet of dark blue comforter to cover it and make it look, well, comfy. I trimmed it off with pine lattice that I screwed into the MDF to keep the sheets at tension. It looks really nice inside.
Was that enough sound treatment?
I mounted some bass traps in the corners because I sensed a buildup that needed fixing.
Has this booth proven its worth yet?
I had a total of eight singers in there at one time, for a group-shout segment during a Melissa Manchester session, and the whole thing neither creaked nor groaned! People feel good in there, as you can tell from the happy smile of the amazing vocalist Vann Johnson in one of the photos!
Last question—how long, how much, how good?
It took me about three weeks to build this. With what I know now I think it could be done in a week, with help when help is needed. I bought everything in local retail stores. The final bill came to about $1500. That could vary, depending on where one buys, and new or used. At first I was a bit disappointed that there is still some sound intruding into the booth from the outside, but it turns out that it doesn’t end up in the microphone in any significant way. The sound is warm and tight; especially acoustic guitars and percussion sound very crisp but not brittle. I’m getting excellent results.
Now we could talk about air conditioning, but that must be a discussion for another time!
Stephan Oberhoff can be contacted through us, at firstname.lastname@example.org.