Recording - November 2019 - 31

If any of these five conditions are not met, there is likely to
be quite a bit of frustration, caused by delays, the expense of
hiring a contractor to complete the build, or the purchasing of
more materials for a rebuild if a design fails in the process.
Some treatments are easier to build than others. Broadband
absorbers, which usually consist of an absorbent material like
fiberglass or Rockwool, enclosed in a frame and covered in fabric, are relatively simple to build. Diffusors are quite a bit more
complicated as there are several types, each with their own set
of design parameters. There are also various hybrid diffusor/
absorbers, as well as tuned pressure absorbers constructed to
target specific bass resonances in a room. All of these require
higher levels of skill and craftsmanship to produce. Also, most of
these devices won't work if the design is not executed accurately. So, it's essential to make sure you know what you are getting
into before committing to a DIY build.
Where DIY builds make more sense is when constructing
the large, 24" thick built-in / false wall treatments discussed
above. A big reason is because you do not need to ship these
panels, which can add significantly to your cost. Oversized
shipping fees add up quick.
The least successful DIY projects usually come from those
whose only motivation was to save money. If your DIY drive to
save cash overrides any of the five conditions above, you may
wish you'd just invested in commercial treatments in the first
place. Commonly, you will underestimate the amount of time
and skill level required to build devices that perform well and
look good. Wrapping the fabric over a panel so that it's tight
and consistent, with no visible seams or creases, and with neat
corners on all sides, is much harder than it looks! It takes time,
practice, and extra materials to pull off. I've had clients who
thought they could whip together a few dozen panels in an
afternoon, only to discover weeks later that they aren't capable
of producing the results they hoped for.

THE SAFER OPTION

For this reason, commercial treatments from a reputable
company with a strong track record and published performance data on its products are always the safer option. The
best manufacturers will help you select appropriate products
for your room and your budget. Most treatments come already
assembled and only need to be installed, and the construction
quality, fit, and finish will be both consistent and high quality.
Despite my role at a commercial company, I decided to DIY.
As per my list above: I enjoy making things, I have the right
tools, and I am confident in my designs, having tweaked my
plans over many years.
I also challenged myself in this build to use materials that are
commonly available at a good lumberyard or local box store-
nothing exotic. However, my designs aren't that much different than
what I spec every day for clients with GIK acoustic treatments.
My treatment strategy for this room could be accomplished
either way. Let's go through my DIY procedure, and contrast
this with what I would do if I were using commercial panels.
As mentioned, the most significant limiting factor in very
small rooms is the amount of space available for treatments.

My room's layout, showing the desk placement, the
shelves & guitars on the rear sidewalls, and all the
treatments (shown in brown) in place. Ceiling panels not shown. Drawing done with the GIK Room
Acoustics Visualizer, available online at
www.gikacoustics.com/room-acoustics- visualizer/.

FIGURE 1
First, I had to decide where I would not be putting treatments. In
my space, this would be the front wall behind my desk and the
side walls behind the listening position. The desk and speakers
have to be as close to the front wall as possible. This leaves little
space available for treatments, apart from in the corners. The
front wall behind the speakers is the least important to treat. On
the rear sidewalls, I needed space for guitars hanging up on
one wall, and a shelf system for storage on the opposite wall.
Both things had to be somewhere in the room, so I put them
behind the listening position, leaving 4' of space between the
corner soffits and the shelves/guitars.
I wanted to fill up the remaining spaces with treatments. So,
let's look at each strategy.

CORNER SOFFIT BASS TRAPS

We'll start with the corners. I only have three corners available because of the entrance door. Luckily, those three have just
enough room for soffit-style bass traps. These traps are about
17" square and should go floor-to-ceiling. I decided to make
each DIY corner soffit a single large one. Alternately, you could
stack two GIK Soffit Bass Traps in each corner. The benefit is
that each one is shippable in a standard box. 6 GIK Soffits,
two stacked in each of the three available corners, are shown
above in Figure 1.
Soffits do a great job of maximizing effectiveness while minimizing room footprint. They perform similarly to 'SuperChunk'
-style bass traps, well known in the DIY community. Their construction entails cutting triangles of absorbent material into 24"
x 24" sides with a ~34" diagonal. A 2'x4' sheet of material
RECORDING November 2019

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Recording - November 2019

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