You're probably tracking too hot. Here's
why...
This entry was viewed over 110,000
times in 2008, nearly 300,000 times in
2009 -- And is *still* waiting for
tweaking...
NOTICE: If you don't
want to read any this or just don't care to
understand it, there's a "dumbed down"
version at the bottom.
Let me get something out of the way here -
I'm going to try to keep this very "fool
proof" - I'm not trying to sound like or
present this very scientifically - This is
just the rantings of hundreds and hundreds
of posts on a dozen or more audio forums
exploding like a volcano recorded with lots
of headroom. I just hope to instill a basic
understanding of why certain trends and
common beliefs are just plain bad. And by
the time you're done reading, and perhaps
doing a little experimentation based on
this, you won't need me to prove it. You'll
know it yourself.
Is this a "miracle cure" for bad
recordings? Normally, I'd say no. But with
the dozens and dozens - Easily now into
hundreds of e-mails, phone calls, letters,
forum posts and other forms of
communication from one after the next about
how this advice has completely changed the
way they view recording, I figured I should
put it down in a centralized location. The
sad part, is this should be common sense.
To anyone that grew up "on tape" it
probably is. To those brought up in 1's and
0's, it might not be so obvious.
So, if you've been struggling with
recordings that sound "weak" or "small" or
too dense or "just not 'pro' enough" then
please, read on. If this is about you, you
might think differently soon.
As a mastering engineer, I work on
recordings from pretty much every level of
experience. A few years ago, I noticed
something unusual.
"Ultra rookie" recordings - Those made by
people with little or no experience,
sounded fine. They didn't know any better,
so they didn't have enough rope to hang
themselves with. "Pro" recordings sounded
fine. They know what they're doing and/or
are using gear with obscene amounts of
usable headroom (explained later). The
"middle of the road" engineers with a year
or two - or much, much more experience --
Those are the recordings that sounded
"small" and spectrally challenged. So after
quizzing these people over months and
months, I came up with the following
conclusion...
You're probably recording too hot.
And it's absolutely ruining recording after
recording after recording. And it's the
simplest thing in the universe to correct.
I know, I know -
"It says in the manual
to record as hot as you can without
clipping." Well, I'm going to flat-out
call that B.S. and I'm going to back it up
with a simple (if not somewhat
time-consuming) experiment.
Also as a mastering engineer, let's get
something straight -- I don't like the
"loudness war" going on - But I'm as guilty
as the next in contributing to it. I can't
fight it, as much as I try. Hopefully it'll
be over some day. HOWEVER - With the quest
for LOUD, there are a LOT of engineers out
there shooting themselves in the foot
before they even know how to aim. They
think that tracking loud and mixing loud
contributes to a louder recording after the
mastering phase. THIS IS ABSOLUTELY UNTRUE
and it's generally the best way to make
sure that your recording will NOT have the
"loudness potential" of the average
commercial release.
CLEAN recordings - Recordings made with low
distortion and good spectral balance -
THOSE are the ones that handle the "abuse"
of the mastering phase with flying colors.
This article isn't intended to give you
some secret way of making louder
recordings. But it will almost undoubtedly
give you the ammo needed to make BETTER
recordings. And those BETTER and CLEANER
recordings are the ones that can be LOUDER
recordings in the end.
First, let's get through a little
nomenclature -
dBFS: Deci-Bel (one tenth
of a Bel) Full Scale -- On the digital
recording scale, -0dBFS is the hottest
signal you can have. "All ones." Top of the
scale, can't get hotter, etc. Always
"minus" as you can never go higher - So the
reading will always be a specified amount
below 0.
Line Level / 0dBVU: Just
what it says. Line level. 0dBVU on an
analog VU (volume unit) meter. Pro (+4dBu)
or consumer (-10dBv) level, it's line
level. We can also refer to this as RMS
(Root Mean, Squared), or a level over a
specific amount of time. You *can* go above
or below 0dBVU. It's simply a nominal level
to which basically everything audio is
related to.
Headroom: The space
between a nominal signal (in this case,
line level) and the point where the circuit
fails. In digital, basically anything under
full scale (-0dBFS) would be considered
headroom. In analog, it's the space between
0dBVU and the point where the circuit clips
(failing completely). In analog, there can
be a big difference between "headroom" and
"USABLE headroom." We'll get into that in a
bit.
Steak: From the old Norse
"steik" meaning "roast" -- A slice of meat,
typically beef, usually cut thick and
across the muscle grain and served broiled
or fried (thank you, Wikipedia).
So - You have a microphone and a preamp
going into a converter or sound card. Those
converters are calibrated at LINE LEVEL. In
most cases, over the last several years,
most I've seen are calibrated to -18dBFS =
line level (or 0dBVU). In other words, if
you run a steady signal (a sustained note
on a keyboard for instance) through a
preamp and turn up the preamp gain until
the VU meter reads 0dBVU, at the converter,
it will read -18dBFS (or -18dBFS(RMS) --
full scale, but measured over time).
THIS IS WHERE YOUR GEAR IS DESIGNED TO RUN.
This is where it's spec'd at. You will have
a decent amount of headroom, the lowest
distortion, the best signal to noise ratio,
etc., etc., etc.
around this level or
lower. Some gear - usually very
high-quality stuff, has a good amount of
usable headroom above this level. A lot of
"budget friendly" gear does not. So all of
this advice is *more* important if you're
using "okay" gear at the input. EVEN YOUR
DIGITAL CONVERTERS are ANALOG components up
to the converter itself. They don't want to
be "beat up" all the time either.
Let's look into headroom -- Above that
0dBVU/-18dBFS range, digital headroom is
simple -- Perfect, perfect, perfect,
perfect, CLIP. The signal is "what it's
supposed to be" until the point of failure.
Analog gear (your preamp, compressors,
outboard signal processors, etc.) isn't
like that... It's more like "Perfect, a
little noisy, "tight" sounding, spectrally
distorted, CLIP. The converter's job is
simple - Reproduce the signal it's fed
digitally - whether that signal is clean
and dynamic or distorted and squishy. The
analog chain's job is anything but --
Typically, you're adding 20, 30, maybe 50dB
of gain to the incoming signal. The preamp
is working - not just "passing" the signal.
And that signal can start to suffer from
noise, distortion and dynamically dependent
(varying along with volume) spectral
imbalance (a skewing of the overall
spectrum from an EQ standpoint).
In other words, a nice, thick, chunky
guitar tone (for example) might have
different characteristics depending on how
hot the signal is. The highs might be open
and airy and then the signal gets loud for
whatever reason and the highs either get
swallowed up, or perhaps get very harsh and
strident. In any case, it's an
inconsistency that isn't' there when the
levels are more "normal." Even though the
analog gear probably has spec'd headroom
well above digital's full-scale, it doesn't
mean that signal actually has the integrity
it should up to that level.
So what happens is simple - A signal is
recorded that's too hot (usually to "use
all the bits" which again, is a bunch of
BS). It overdrives the input chain not
unlike a guitar preamp overdriving a
Marshall stack (well, not that much, but
the premise is the same). Now, after all
the other tracks are recorded, ALL of them
need to be attenuated by 12, maybe 15dB or
more so the mix doesn't clip. Those
distorted, spectrally questionable,
squishy, noisy tracks all get turned down.
Are you seeing my point yet?
When you take a steak and cook
it until it's burnt, it's burnt. If you
pour ice cubes all over it, it doesn't make
it more rare - It makes it a cold, wet,
burnt steak. No matter what you do, it's
still burnt. Just like if you record too
hot.
But if you cook a steak a little too rare,
you can always heat it up a bit later. You
can microwave it without it turning into
leather. You can pan-fry it for a few
minutes and it's still a tasty, savory
piece of steak.
When you use up all your headroom right
away, you don't get it back by turning it
down. It's gone forever. Sure, you can
increase mix headroom or the headroom at
the buss - But it's not going to make the
track less distorted or fix the skewed S/N
ratio.
Here's your experiment -- You'll need a few
Y-cables (let's not get into the technical
aspects of splitting a mic signal - It's an
experiment) and at least one stereo
(2-channel) preamp.
Record a song using as many tracks as you
feel fit. The more, the more apparent.
You're going to split the mic signal and
record each twice simultaneously. On one
channel of the preamp, set the gain so it
peaks between -18 and -12dBFS at the
converters and record them to odd numbered
channels. On the other, set it as high as
possible without clipping and record them
to even numbered channels. Record some
guitars, drums, maybe piano, of course some
vocals, keyboards, go nuts.
Set all the odd numbered ("normal" level)
channels to unity and toss up a rough mix
to a stereo buss - Which should be a piece
o' cake. Switch over to the even numbered
channels and figure out how much you're
going to have to attenuate them all so the
main buss isn't clipping constantly. It
might be a lot. Could be a 10-15dB cut on
all channels before you can even think of
starting to do anything else. Send those to
a stereo buss. Solo the busses, one at a
time, and try to match the levels between
the mixes. You'll probably immediately
notice that the "normal" mix is much more
open, dynamic, airy, clear, clean, with
much more "sonic space" between the
instruments than the "hot" mix.
Now, add a limiter on the main buss. Run
the "hot" mix into it and bring the level
up until it starts to obviously distort and
fall apart sonically. Then switch over to
the "normal" mix - which should now be
"rammed" by the same amount. If your
experience is pretty much like everyone
else's, the "normal" mix is *still* much
more open, airy and dynamic with less
distortion and more "crankability" than the
other.
THE "DUMBED DOWN" VERSION:
Stop recording so hot. Instead of trying to
get your tracks to peak at -2dBFS, have
them peak between -20 and -12dBFS and your
recordings will almost undoubtedly sound
better. Mixing will be easier. EQ will be
more effective. Compression will be
smoother, more manageable and predictable.
You're in the age of 24-bit digital
recording - Relax and enjoy the headroom.
Even if your only concern is the volume of
the finished product (which would be a
shame, but it happens), recordings made
with a good amount of headrom are almost
undoubtedly better suited to handle the
"abuse" of excessive dynamics control.
QUIETER recordings have more potential to
be LOUD later. It's because they're usually
better sounding recordings in the
first place.
John Scrip - MASSIVE
Mastering -
http://www.massivemastering.com
Tags: mastering|recording