Recording - November 2015 - 18

The components that are most commonly used
to treat rooms would involve low frequency
absorption (bass traps), panel absorbers (mid
and high frequency absorption) and diffusion.
In terms of low-frequency absorption, your readers are probably most familiar with fiberglass
absorptive panels that you can buy from
Primacoustic or GIK Acoustics, for example. But for
the most part, if they are one or two inches thick,
they are only effective down to about 500 Hz or so,
as I said. So the way you extend the low-frequency
response of these products is by getting as much air
space behind them as possible, which is why some
of these companies offer products that are designed
to go into corners. So you could take any of these
panels and put them in the corner, or let's say in the junction of the
wall and ceiling, where you're trying to get as much air space
behind it as possible. And that dramatically increases the lowfrequency response. All small rooms will require a fair amount of
low-frequency absorption.
The places where you get the most amount of low-frequency
buildup is in the corners, so you have to place absorbers at the corners, at the ceiling/wall junction or the floor/wall junction. To get

some control of the low-frequency energy in the room, I recommend
putting-if you have the space-corner traps in all four corners of
the room. And if you have additional space, try to put them cutting
the corner of the ceiling to the wall. So, in essence, you're creating
another corner trap in that area. That's the best way to get the lowfrequency control of the room. In terms of calculating how much
absorption you want in the room, no more than 35% of total surfaces should have absorption. If you start putting more than that in
there, the room starts feeling overly dead.
A cloud over the mix position will dramatically improve monitor
performance. The larger the cloud, the better, and the more air
space between the cloud and the ceiling is also ideal. Wall panels
should also be placed to eliminate flutter echo between parallel
hard surfaces and early reflections from your speakers.
What about carpeted floors?
I tend to prefer hard floors, however, carpet can be fine. The
thing to remember is carpet absorbs only high frequency energy, so too much of it will tend to make the room sound dull. If
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RECORDING November 2015

the ceiling is parallel to the floor and hard, the
carpet will eliminate flutter echo.
What about diffusion?
Diffusion is another excellent way to improve
the sound of a room. Think of it this way: if a
sound waves strikes a wall, instead of that energy bouncing directly back like it was a billiard
ball, it reflects energy back into a wide spread of
angles, so it spreads the energy throughout a
much larger area, eliminating flutter echo. It also,
generally, makes a room sound bigger, so if you
have a small room and you're wanting to make
it feel like it's a slightly larger room, diffusion is
an excellent way to go.
The studio is filled with miscellaneous things; it's not an empty
room, so it actually produces lots of specular diffusion. This is
because sound waves, instead of just striking a wall, are striking furniture and bits of equipment that deflect the energy in different directions. That's why you eliminate a fair bit of flutter
echo and other problems when you start putting a lot of things
in a room.

How do you treat the room differently for monitoring and for
actual recording, and can you combine them somehow so you
have the best of what you need for each of those tasks?
If you have only one room, that can be a challenge, but I
would lean toward making the room the best possible monitoring
environment. It will most likely not be as reverberant as would be
ideal for tracking, but that won't pose any significant problems.
You could always bring in some hard gobos to brighten up the
room if needed.
What can you share about speaker placement, as well as
speaker size relative to room size, and anything else about
monitoring that you think is important?
A critical component to monitoring should be the speakers' position:
an equilateral triangle relative to the mixing engineer's position, all the
angles are 60 degrees, and my recommendation is the rear focal point
of the speaker should be a little behind you, maybe six inches or a foot
behind you, so it widens the sweet spot a little bit. The acoustical axis

Table of Contents for the Digital Edition of Recording - November 2015