by Marty Cutler
LAST MONTH, WE REVIEWED DIGITAL TOOLS THAT DETECT ACOUSTIC PROBLEMS
in your studio and compensate for them to help you do better mixes. They generate test
tones, listen with a measurement mic, analyze the results, and make EQ-based corrections
at the output stage of your recording system. As effective as this approach is, it
can’t correct what your room may be doing to your sound at the input stage—mainly to
anything you record with a mic. So while that synth bass you bounced to disk sounds fat
with plenty of attack, the electric bass you re-amped may sound thin and papery, and
vocals may sound smeared and ringy.
Testing Methods
In small, parallel-walled rooms, bass frequencies
can accumulate in corners and become boomy, or
cancel each other out and become quieter or even
inaudible. Higher frequencies bounce off the walls
and can cause fl utter echoes, ruining the imaging of
sounds in that range. With that in mind, we tested acoustic treatments from three companies, made
listening observations, and analyzed the results
through IK Multimedia ARC—it takes highfrequency
issues into account as well as more common
low-end problems, and while not a reference
spectrum analyzer professional studio designers
would use, it is a tool real-world musicians are more likely to have. I sent each company a mockup of my
room, with dimensions, doors, windows, and anything
else that might alter the path of sound waves
issuing from my monitors. Th e companies then
sent me room treatments they deemed appropriate.
Fair warning: You’ll need to be handy with
a drill and anchors to get some (but not all) of
these products up. Because mounting panels can
be a trial-and-error process, it would be great if
more manufacturers provided alternate mounting
materials suited to temporary placement. I’m
not keen on poking multiple holes in the old drywall
of my old house, especially in something so
ephemeral as a spare bedroom studio. Given my
skill level, I decided to use industrial-grade Velcro
wherever possible.
Primacoustic
primacoustic.com
If your room suffers from a particular acoustic
foible, Primacoustic has a solution for it, ranging
from isolation tools to bass traps, gobos, diff users,
and much more. You can pick and choose
treatments on a piece-by-piece basis; the website
is immensely helpful at explaining room issues.
You can also select kits designed for different
sized rooms from project studios to nightclubs to
home theater.
My room falls under the category of project
studio, and with that in mind, Primacoustic sent
me their London Kit 12, which comprised a pair
of 24" x 48" x 2" Broadband Panels, eight 12" x
48" x 2" Control Columns, and a dozen 12" x 12"
x 1" Scatter Blocks. The panels were primarily
dense fiberglass with an aesthetically pleasing,
grey, textured fabric.
Mounting hardware was a box of drywall
impalers, screws, anchors, and even the proper size drill bit. I was expecting standard bass
traps, but according to Primacoustic, the larger
Broadband and Control pieces cover a very wide
range of frequencies. Bear in mind that kits are
generally starting points, and Primacoustic offers
a variety of hardware a la carte for fine-tuning.
 |
| Fig. 1. A desktop view of a pair of Primacoustic Control Columns flanking either side of a single Broadband panel. |
My attic door, situated at the left front corner
of my space, precluded putting a bass trap there.
Instead, I initially mounted the larger Broadband
panels at the front of my room, directly parallel to
my rear wall: the left unit temporarily over my window,
and the right one on the wall directly in front
of me, with a couple of Control Columns at the
right and left of the right-hand Broadband panel.
(See Figure 1). Th at left mostly smaller spaces,
where I could mount a few more columns and fi ll in
the gaps with the smaller Scatter Blocks.
Now to listen. As much as I loved my untreated
room sound, I was immediately and unequivocally aware of a fabulous improvement in clarity. Th e
imaging, which my Tannoy Reveal monitors
always provided in spades, was even more spacious
and accurate. I work by myself most of the
time, but I collaborate frequently enough that I
appreciated the broader sweet spot, although the
bass was more emphatic, bordering on boomy, in
the left rear corner of the room. Th at made sense,
as it was the corner with the least available treatment.
Finally, I worked a mixdown using the same
sequence material I used for last month’s story.
Due to the balance and clarity the treatment provided,
it was significantly easier and quicker to get
results that were pretty darned consistent across a
variety of playback mediums, including my home
system, an iPod with earbuds, and my car stereo.
The ears say one thing, and inevitably, measurement
software says another, so I loaded
up ARC and swept the room. Interestingly, the right channel profiles were remarkably similar
with a lot of mild mid-to-high-frequency bumps,
albeit with a bit of an increase in amplitude in
the right channel in the treated room. Below
200Hz, the readouts were similar before and
after, again, with slightly increased amplitude peaks at roughly the same frequencies,
including a pronounced dip in the left channel
at about 100Hz in the treated room. I’m
guessing I would’ve seen more improvement
here had I put proper bass traps in both
forward corners.
I tried mixing through ARC in conjunction with
the room treatment. Oddly enough, I preferred my
new Primacoustic environment without it, as the
audio took on a bit of a brittle high end with it.
In fairness, ARC offers alternate frequency rolloff
curves, which could likely smooth this out.
RealTraps
realtraps.com
If your workspace is as compact as mine, the fact
that your space changes dynamically is a given.
Add one 19" rack, and furniture may move.
RealTraps recognize that and offers modular
systems on stands that you can move as your
space changes. Primacoustic does this as well,
but mainly for their portable gobos such as the
Freeport series.
 |
IK Multimedia ARC measured room
response before and after installing
acoustic treatments. Get screenshots
of the results and room diagrams at
keyboardmag.com/july2012. |
I received four MiniTraps, designed to
catch bass in corners; three MicroTraps, whose
one-inch thickness is focused on mid-to-high
frequencies; a couple of stands, and the requisite
mounting hardware.
Mounting is deceptively simple. Once I fully
grasped the setup procedures, it took me only
minutes to attach and use the MicroTraps, which
I’d mounted on stands. The assembly instructions
would be better with step-by-step diagrams for
the mechanically challenged such as myself.
Because these units are free-standing, I
had no issues with the doors in the left-hand
corners; I could put traps there while working, then slide them away for door access (see Figure
2). A MicroTrap on a stand to my left stood in
front of the closet door and another in the left
front window tamed reflections from the glass.
Th e third Micro perched in a groove in my righthand
window for similar reasons, with the added
benefit of dampening outside traffic noise.
The MiniTraps in the corners did a great job
of cleaning up the bottom end, and making it
consistent over a fairly wide area. Imaging was
excellent, but for some reason, upper frequencies
and transients seemed present enough, but
without the “sparkle” of the Primacoustic kit.
Likewise, the sampled acoustic bass seemed to
lose much of its high-end snap.
After moving things around a bit, I defaulted
to relying on just a heavy curtain in my righthand
window, and moved that trap to a stand on
the right, and parallel to the microtrap on the
left. Now, imaging and clarity were great—the
“front” of each instrument, including the bass,
was clearly defined. In more exposed moments on the track, the beautiful Ron Carter-style
growling vibrato on the instrument shone
through. Th e sparkle present in the Primacoustic
set was replaced by well-defined but velvety
highs. Ultimately, this smooth high end would sit
well with long mixing and tracking sessions, in
which overly present treble can be fatiguing.
 |
Fig. 2. RealTraps’ modular design
makes it a snap to reconfi gure
your studio. A MiniTrap in my front
window absorbs nasty wall-to-glass
refl ections. A MicroTrap sits in each
corner to break up bass frequencies. |
The measurements from ARC didn’t
necessarily support my perception, however;
if anything, dips and bumps in the amplitude
of frequencies over 200Hz were slightly less
dramatic, but only faintly so. In any event, I was
satisfied with the resulting transferability of the
mix across playback systems.
Pairing RealTraps and ARC was somewhat
more listenable than with the Primacoustic
treatments, but I heard no significant difference
between using both and using RealTraps alone.
Apart from a noticeably lower amplitude overall,
which was probably just the position of the
ARC plug-in’s trim knob, I couldn’t hear any
perceivable change in timbre or image.
Auralex
auralex.com
As with the other manufacturers, I sent them a
mockup of my room, but I also fi lled out their
room analysis survey at their website. Here, you
outline the purpose of your room, the typical
music you record, the dimensions, and so on.
You also profile your room’s acoustic symptoms
and submit a diagram. Auralex then
develops a custom treatment strategy based
on your needs, budget, and visual aesthetic.
I received a dozen two-foot square, one-inchthick
Sonolite panels, which are made of fabricwrapped
acoustic foam and mount on walls or
ceilings to tame reverb, ringing, and fl utter echo;
a pair of ProMax portable broadband absorbers—
large foam panels on stands (they serve
as bass traps in my setup, but you can deploy
them as isolation for tracking vocals and acoustic
instruments); and a box of four bamboo Peak
Pyramid diff usors.
Auralex had sent me detailed placement instructions
for everything (download the PDF at
keyboardmag.com/july2012). Putting everything
together was simplicity itself. In a couple of instances, however, placing the Sonolites required
a few detours from their plot, which had no
detrimental eff ect on the overall treatment plan.
Mounting the Sonolites was a breeze, thanks to
the double-sided adhesive pads provided; I even
removed and repositioned them once or twice when my measurements were a little off with no
damage to the walls (see Figure 3).
The ProMax Absorbers were easy to assemble.
Each absorber is halved and dovetailed together
around a cylindrical insertion space for mounting
on the provided mic stand. This provides some flexibility in adjusting the height of the foam
business end of the absorber.
 |
Fig. 3. Auralex Sonolite pads on the walls surround a ProMax Absorber on a
stand. My monitors sit on Auralex MoPADs, which decouple them from the
desk and preserve low end. |
I arrayed the Peak Pyramid Diff usors above
my head, slightly in front of the overhead fan
with each pyramid pointing 90 degrees away
from its neighboring piece; according to Auralex,
this helps disrupt overhead reverb and harsh
reflections without completely deadening the
space. The Pyramids were too heavy to mount
with adhesive; the job called for drywall anchors
for my ceiling. I’m not terribly handy with a drill,
so I pressed my wife into service. (She can set up
a mean patch bay, too.) Handily, Auralex provides
the mounting anchors and screws.
When the dust and drywall cleared, I was
rewarded with a remarkably clear and consistent
sweet spot with burnished highs, a distinct midrange,
and clear bass. During denser moments,
you could really make out the growling vibrato on
the acoustic bass, and more importantly, its distinctive
envelope, rather than the tonal thud I used to
hear when things got busy. I could even hear the
release samples during more exposed passages. A
gorgeous pedal-steel-type pad from Spectrasonics
Omnisphere retained its character amidst
mandolin tremolos, acoustic guitars, a swirling phased Rhodes, and a sawtooth pad. In my untreated
room, that would’ve been a recipe for the steel to get
lost in the sauce. It was easy for me to carve out space
in the mix for each instrument. Walking from left to
right in front of my desk, the sweet spot was not
nearly as broad as the Primacoustic treatment,
but broad enough to invite a collaborator or two.
ARC results explained much of what I heard in the high end above 2kHz, whose divergences
from the ideal fl at response were minor—and
very consistent over both channels. Mixing with
ARC active proved to be a decent pairing in this
instance. I enjoyed a bit of a wider sweet spot
marked by more consistency in the bass. Clicking
on ARC’s Full Range Bass Correction added a bit
more bottom without smearing the notes.
Conclusions
The Primacoustic London Kit is a class act.
Attractive as well as eff ective, it can easily blend
into a home studio without looking out of
place. Most importantly, it provided a balanced
frequency response throughout an impressive
amount of area around my central listening post.
Realtraps off ers robust and reasonably priced
solutions for the home studio. I can’t emphasize
enough how crucial it is to be able to adapt your
room conditioning to the minute developments
that can aff ect small spaces that are pressed into
service as recording studios. Auralex provides a
comprehensive set of aff ordable tools for room
treatment. Once again, the modular design is
a tremendous boon to small project studios where you’re often moving things around.
No room treatment product is an end-all
solution. A glance online at each manufacturer
will reveal an incredible variety of treatments for
every nook and cranny in your room, but don’t
go to the point of anechoic overkill—no musician
likes a completely dead room.
The concept of a room with a perfectly flat
response is a myth. What should matter are your
ears. In each case, I was able to get a better aural
picture of each sound’s stereo placement, timbre,
and loudness in my mixes than I had when I had
started. I mixed, tweaked, and adjusted with a
solid idea of what my tracks really sounded like—
resulting in a more consistent listening experience
when I was done.