January 27, 2008 - 20:17 Filed in:
Articles
If you can't trust your room, the greatest
monitors in the world are worth a bowl of
warm sinus fluid.
There are very few hard and fast "rules" in
recording - Two that hold true are:
1. You will only ever hear as accurately as
your monitors allow you to hear.
2. Your monitors will only ever sound as
good as the room they're in allows them to
sound.
Having your room "in order" acoustically
means success or failure. The best engineer
in the world can't tweak what he can't
hear. And "The Room" always seems to be
skipped over when setting up a recording or
mixing space. Many times, in favor of some
sort of worthless bling.
So - To take away any excuses and let's get
that room set up.
DISCLAIMER: I'm not an acoustics expert.
I'm not a physics major. This is going to
be terribly "dumbed down" for the most
part. If you want "serious" acoustics
consultation, contact a serious acoustics
expert. This is just some basic info to get
a hobby/project space into decent shape
without having to go through a training
course.
First - Positioning: You don't want corners
- You don't want to be up aginast a wall.
Without getting into the physics of "why,"
there *is* an "ideal" spot in pretty much
every rectangular room -- .38 the length of
the long wall from the short wall. That's
the spot with the least offensive
reflections and collisions (peaks and null
points). SO - You're in a room that's
12x15. .38 of 15 is 5.7 feet. That's the
mix position. That's where your head goes.
Speaker positioning: You've probably heard
it a hundred times, but you want you and
your speakers to form an equilateral (all
sides equal) triangle. Now - Because you're
5.7 feet from the wall, that doesn't mean
you're going to push the speakers against
the wall and space them 5.7 feet apart -
You don't want the speakers up against the
wall. Too much low end buildup. I'd go with
at least 1.5 feet. At least. Minimum. The
more the merrier.
So, figure you place them 1.7 feet away...
Do you see where I'm going? The speakers
are 4 feet away from you, four feet apart,
equilateral triangle. It's that simple. The
angle of the speakers is next -
You don't want them pointing directly at
your head - Have them converge maybe 2-4
feet behind you. You can match the angles
by positioning yourself in the middle of
the room and looking down the sides of the
boxes.
Now go out and get some drink holders or
egg cartons and cover the walls with them
and you're set!
Okay - I'm joking about that last part and
I hope you knew that. Drink holders, egg
cartons, acoustic foam -- Not what you
need.
The room: Sound is energy. Low frequencies
consist of a lot of energy. High end, only
a fraction by comparison. A rather common
mistake by recording hobbyists is to cover
the walls with drink holders or egg cartons
(which is flammable - and acoustically
worthless) or toss up a bunch of acoustic
foam sheets.
Acoustic foam is great stuff for absorbing
high end flutter and comb filtering. Which
is almost nothing on the grand scale.
What's worse is that along with all the
flutter, the foam absorbs the ambience in
the high end. That leaves a very "dead" or
dull sounding space in the highs, but does
nothing for the low end problems. Thus, the
low end problems are now allowed to take
over. So instead of just "dull" you get
dull
and muddy.
Low end first. Always, ALWAYS the low end
first. Broadband absorption. Rigid fiber /
rock / mineral wool. All four corners,
floor-to-ceiling if at all possible.
High-side corners (where the ceiling meets
the walls) in line with the mix position is
a safe bet also.
Low end waves are very long - And consist
of a lot of energy. Therefore, it takes up
a lot of space and requires much more mass
(far more than a few sheets of foam) to
absorb that energy and turn it into heat.
The corners are the important part because
like a funnel, the walls direct the energy
into the corners where it builds up more
than any other part of the room.
And what about that high-end flutter? That
gets directed into the corners also... Take
care of those corners, and rid yourself of
most of your problems from the start. Any
other rogue flutter or comb filtering can
be handled with a minimal application of
Sonex (or far less expensive Auralex)
acoustic foam products. A sheet or two is
probably all you'll need - If you need any
at all.
A dozen broadband traps can be the best
investment you can ever make.
So in short - .38 of the long wall from the
short wall. Equilateral triangle without
being too close to the walls. Broadband
trapping (as much as you can get - It's
very easy to ruin a room with too much
foam. It's nearly impossible to use too
much broadband trapping).
DON'T STOP HERE: For more information on
the physics behind all this, visit two of
the pros I alluded to earlier:
RealTraps and
GIK Acoustics. No
coincidence, they're also two of the
most popular manufacturers of
broadband traps.
John Scrip - MASSIVE
Mastering -
http://www.massivemastering.com
Tags: room acoustics|recording