For a moment, forget about your microphones,
your monitors, your front end, your back end,
and your DAW. Your forest amongst your trees
isn’t your hardware and software, it’s your
environment — the room in which you do your
critical listening.
Thus, we suggest periodically setting aside a
small percentage of your business time (and
funds) purely for removing at least one negative
acoustic characteristic from the space in which
you listen. Even if you don’t have an actual
budget for acoustic materials this year, very
affordable results are to be had with careful
consideration, phone consultation with reputable
acoustic treatment authorities, and just a touch
of physical labor.
Nick Colleran of Acoustics First Corporation is
an industry veteran and expert in the realm of
acoustic treatment materials, applications, and
installation techniques. Based on decades of
treating all kinds of listening and recording
environments — from world-class places to humble
home-based spaces — Colleran generally advises
to make logical, one-byone small changes, then
stop and listen for improvements, if any.
Data Before Dollars
First of all, before you spend a dime on any
acoustic treatment materials, closely analyze
the space you need to treat. Before contacting
an acoustics expert, simple data, pictures, and
measurements should be compiled. “Room shape and
size, what the surfaces are made of, and what
will be accomplished in the room are the
basics,” says Colleran. “We like to see a
half-dozen photographs — front, back, up, down,
right, and left — because we might not know
about the giant pink stuffed elephant in the
corner which affects the acoustics. If it’s a
large room, we like a recording of a balloon
being popped so we can hear it. If it’s
something small, like many control rooms, that
is less relevant.”
Common Problems With Early Reflections
“If the space is for listening to playback,”
Colleran continues, “remove all the first
reflections near the source of the sound so the
sound from the speakers reaches your ears before
the room interferes. Any direct and reflected
frequencies that combine out of phase will
cancel and conversely those frequencies that
combine in phase will be boosted. String
together those valleys and peaks and your
resulting frequency response will look like a
jagged mountain range."
You May Already Own (Or Rent) A Bass
Trap
Nearly all bedrooms have closets, many
residential studios are in cube-ish bedrooms,
and most of these spaces are in need of bass
trapping. Luckily, your closet is a bass trap in
waiting, advises Colleran. “Open it up. If you
have a closet, you have a pre-fab bass trap. The
hanging coats inside will act like the bass
traps back in the late ‘60s and early ‘70s. Just
hang a curtain over it to conceal your
wardrobe.”
In that same manner, adjoining rooms are also
potential bass traps. For one particular job,
Colleran cleverly used the next room over to act
as a larger bass trap. “We worked it in by
leaving a heavy curtain over the entrance to a
bedroom off of the control room,” he explains.
“That gave the extra space for the bass to
‘develop’ so he could hear what was going on
down there.”
Misconceptions, Tips, and Motivations To
Seek Advice
Colleran is quick to point out some standard
misconceptions among audio professionals when it
comes to acoustic treatment materials and
techniques. The most common?
“That foam blocks sound, because it doesn’t.
It’s porous. Sometimes people think that the
shapes [of acoustic panels] are particularly
important. They’re not quite as relevant as
people think they are (or want to make them).
Also, putting a lot of absorption in the corners
of a room does not serve as a bass trap; it’s a
broadband trap, and it’s going to absorb
everything.”
Colleran continues. “Here’s a tip: You can
reduce reverb time (RT) by putting any
absorption in the room, in any position; it’s
not directional, and it just being in the room
takes the RT down. Also, a hanging panel will
absorb on both sides, cutting RT.”
Noting that his thoughts here only scratch the
surface, Colleran unintentionally assures us of
one more fact regarding acoustic treatment
techniques: that good consultation from a
knowledgeable professional is truly valuable,
indeed.
Strother Bullins is the reviews and features
editor for Pro
Audio Review.
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