Making a sound reflection dampener for audio recording

Not too long ago, I got approached by an insulation company, Johns-Manville, asking me to do a project involving insulation. To be honest, I had no need of any insulation projects, but then when I looked at the materials I found that their products are both for thermal AND SOUND insulation!

Since I constantly record audio (podcasts, voice-overs, music) it made a lot of sense for me to make something to help me in that space.

You may be looking at the photos and wondering what in the world this thing actually does. It’s obviously not a sound booth, it won’t stop sound from coming in from most directions.

Well, it’s purpose is to dampen reflected sound when speaking or singing into a microphone.  Typically, some of your voice passes the microphone, hits the wall in front of you and is reflected back to the microphone, slightly delayed. Although it’s a small effect, it does muddy the sound a little bit. This dampener tries to trap the sound so that it doesn’t ever hit anything to get reflected back at the microphone.

It’s a pretty simple project, but is very helpful if you do a lot of voice work.  Let’s check it out!

I started with some scrap 1/2″ plywood that was about 24″ wide.

I measured in 2″ from each side and lightly nailed in a finishing nail.

I bent a scrap of flexible veneer (you could use anything flexible) in between those two nails.

I traced the outside of the arc with a pencil.

You can move the piece in and out to change the overall arc shape.

I measured 2″ out from the line, and made some marks, following the line all of the way around.

I went back and connected those marks. This gave me a second arc that was 2″ away from my first line but had the same shape.

I used a jigsaw (bleh.. don’t like them) to cut out both lines.

Jigsaws cause a lot of tear out on plywood, so I sanded all surfaces smooth.

I used the arc as a template to create a duplicate, by tracing it onto the remaining plywood.

I cut and sanded the second arc in the same way.

Using 1/8″ plywood scraps, I cut several strips 15″ long and about 2″ wide.

Using brad nails, I connected the ends of one arc to the strips.

I also added one strip on the back side of the in the center.

 

I flipped the assemble upright and attached the second arc in the same way.

I added the rest of the strips on the back side of the arcs every few inches.

I made sure to add a strip along the outer edges of both sides.

I cut a strip, about the same length as the inside of the arc, of insulation.

I pushed the insulation into the shape of the arc, trying to evenly compress it.

I cut some black material (about 1 yd.) down. Use fabric scissors if you have them!

I laid the material over one edge and started stapling it in place.

First, I moved down the inside of the arc, attaching the material with staples.

Eventually, I wrapped it around, stretching it tight, both sides of the shape and stapled it down.

I tried to get my final edges on the bottom side of the piece, then I cut off the excess with fabric scissors.

I measured in 8″ from the front edge, on both ends, and set a piece of angle aluminum in place. I marked the width on the angle bar.

Using the mark as reference, I cut down the aluminum on the miter saw.

On the piece, I marked the center point as well as 2″ in from each side.

I used a stepped bit to make the largest hole that I could, on the center mark.

I made two smaller holes on each end, in that 2″ space.

These holes only need to be large enough for a screw to go through.

I measured the 8″ again on each side, placed the aluminum and screwed it into the plywood under the material.

The unit was complete and just sat down around the threads on a microphone stand.

Screwing on a microphone holder tightens down the aluminum, holding the whole assemble in place.