Technical Background - Behringer Eurodesk SX3282 User Manual

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11.

Technical background

11.1 Mixing
11.1.1 Equalization
In the beginning, EQ was an instrument for removing unwanted
frequencies, or compensating for imperfect microphone response
curves, or bumps in a studio's acoustic. It was a corrective device.
Tamla Motown turned that notion upside down in the sixties
with the novel idea that you try to find for each instrument a
characteristic frequency not shared by the other instruments
in the mix. Then you whack up its gain. This makes individual
voices punch through a mix in a slightly unnatural but exciting
way.
In general, corrective EQ usually involves broadband (slope)
contouring, together with narrowband notching of unwanted
resonances. The narrower the notch or "Q", the less the total
signal will be affected.
Finding bad resonances is made easier by first frequency sweep-
ing in BOOST mode.
"Motown" EQ is achieved by applying boost in a fairly broadband
way. The broader the band, the more musical but less instru-
ment-specific the effect. Applying boost over a narrow bandwidth
will sound "honky".For sounds which require drastic corrective
EQ, it is advisable to have a couple of channels of fully compre-
hensive parametric equalization in your rack. (You can always
bounce tracks through the outboard EQ, freeing up the unit for
the next task).
Check out the ULTRACURVE PRO DEQ2496, a superlative
digital stereo equalizer and much, much more.
For "advanced equalization", EQ might be applied to a signal
as follows: First, trim the LF and HF shelves to achieve the
required slope or "loudness". Now use a parametric EQ band to
boost the most significant frequency for each instrument or tape
track. Over all channels, if two or more of these frequencies coin-
cide, then you might have to settle for second best in some cases,
if you want to achieve optimum separation in the mix. Really
nasty frequencies will need notching out.
A vocal signal can be enhanced by applying a significant boost
in the 12 kHz region or higher, above the nasty sibilance region.
This is especially effective if you've got a de-esser patched
post-EQ.
Use the low-cut filter to tighten up channels in a mix:
◊
maybe remove it only for the bass, kick drum, toms, tablas,
didgeridoo and other deliberate subsonics (when recording
classical music ignore this advice).
With the LF set to boost and the low-cut switch activated, you
have got a peak response rather than shelving at the bottom.
Good for tight but deep bass.
Remember EQ contouring can be done with cut as well as with
boost. Cutting away the top and bottom, then pushing up the
gain is equivalent to mid range boost! EQ is not a one way street!
Always reset a channel's input gain (or external devices' output
level) after altering the amount of desk EQ cut or boost applied.
11.1.2 Gain Optimization
PFL (Pre-Fader-Listen) is the way to set a desk level. Master
aux send levels are fixed at unity gain. As the mix progresses,
more and more channels are likely to be sending to effects via
the aux buses, and it's best to PFL all sends just before setting
up for the final mix.
Outboard reverbs etc. should all be made to work hard. There's
no point in having an 85 dB dynamic range if the input meter of
your reverb is barely flickering. On the other hand, digital distor-
tion is not one of the nicer noises around. You'll have to rely on
your ears to detect digital distortion, since different outboard
processors calibrate their meters differently.
If you hear distortion, turn down the input on the FX unit, and
turn up the desk's aux return input.
99 times out of 100 distortion in the aux send > FX > aux return
loop will come from the FX unit (FX gain too high), and the same
goes for a high noise level (FX gain too low).
Analog multitrack tape should be driven quite hard, since its
dynamic range (without noise reduction) is likely to be 20 to
30 dB worse than other elements in the recording chain. Try
to record bright. You can always mix back duller. Brightening
up an off-tape signal will bring up the level of tape noise. With
digital tape or hard disk you have plenty of dynamic range, and
treble pre-emphasis is not often necessary. Just don't let the
signal distort!
When mixing or recording, keep the channel fader levels around
or below 0 dB. If you do find the faders creeping up or down,
apply a suitable offset over all channel faders, and try to control
your bad habit in future!
EURODESK SX3282 User Manual