The framing for the base will be fastened to the subfloor using isolation pads to minimize migration of low frequency vibrations (sound is energy in the form of vibration). The vibrations can come from music being played below, mechanical units attached to the house, footsteps outside the booth, etc. The idea is to decouple the structure of the booth from the existing structure and the same will apply throughout the build for the framing, drywall, etc. In this case, simple workout mats were cut up to act as isolation pads and you can find links to materials for the booth near the bottom of this page.

Base frame with isolation pads.

And by the way, when you go to build the frame, make sure everything is nice and square because everything built on top of the base will depend on it. There's plenty of information on how to square things up online, or if you have a friend or relative that's a carpenter, even better.

A nice, squared up frame.

For the frame of the base, 2x4's are being stacked one on top of the other which comes out to 3" in total height. That's perfect because the Roxul insulation that's being installed is also 3" deep. Now that the frame is built and attached to the floor by toenailing 4" screws into the floor, we can install the insulation.

A four inch drywall screw toenailed into the floor through the side of the base frame.

Let's watch Andy cut and install a little bit of the Roxul insulation. Although contractors frequently use Roxul with little to no protection at all, remember to wear gloves and a mask just in case the mineral wool material irritates your skin or lungs.

On that note, make sure your framing is spaced 16" on center if using the 15-1/4" Roxul so it fits nice and snug. If you end up with a smaller than 16" space near one side, just cut the insulation to fit. In all cases, don't pack the insulation tightly or double up on it in the same cavity thinking it will be even more effective; it doesn't work that way. Just make sure everything is fairly snug with no gaps and you'll be good-to-go.

Now that the insulation is in, it's time to install a 5/8" layer of drywall on top of the frame in prep for Green Glue. Installing drywall on a floor may sound strange, but it will make sense when we get to applying the Green Glue.

You don't see that everyday...

If your frame is square, the drywall should line up nicely with the edges of the base frame. Note that it's only necessary to screw in and slightly countersink enough drywall screws to keep the drywall layer in place for the next step. Also, be careful not to step on the drywall between studs because you could easily break through and have to start over.

Countersink the screws just below the surface of the drywall.

Now it's time to install the Green Glue compound and a layer of 3/4” plywood. The Green Glue tubes are 28oz so you'll need a large caulk gun. Again, a link will be provided so you can be sure you have the right size. Use two tubes of Green Glue compound for every 4’x8’ sheet of drywall. The pattern doesn't matter. What's important is that it's evenly distributed. Stay 2" away from all edges with the Green Glue because the plywood installation will cause it to spread out and you don’t want the glue spilling out over the edges.

Andy chose to spread the glue on the 3/4" plywood, which works just as well.

Making sure the 3/4" plywood is squared to the frame, install it over the drywall and fasten it to the frame using 2-1/2" drywall screws. Make sure you also slightly countersink these screws as you did with the drywall. Be sure to install the screws around the perimeter approximately 8" apart. Also be sure to install screws wherever you have 2x4's on the inside of the frame. Your floor is now securely fastened and ready for the next step, which we'll get to in part two of this series.

The finished base for the booth.

I'm sure some of you are wondering what the Green Glue is all about, so I'll explain. The Green Glue compound never completely hardens and it absorbs vibration VERY well. Remember what I said about sound being energy in the form of vibration? Well, Green Glue acts like a giant catcher's mitt. It soaks up the majority of the vibration and doesn't allow it to pass through to neighboring materials. Man, ya gotta love science…

And for those seeking out a list of materials for the booth, here’s a link for you.

Ok, that's it for now. See you and The Colonel in part two!

Tim Tippets is a professional voice over artist and audio technologist. If you need audio assistance, he can be reached at info@votechguru.com Follow and like his Facebook page at https://www.facebook.com/votechguru/ and on Twitter at https://twitter.com/VOTechGuru

© Tim Tippets / VO Tech Guru 2017