Mixing - Working with the Mighty Mult
Which old-school engineering routine can be
used to increase headroom, pre-condition effects
and sidechain inputs, and simplify writing
automation during mixdown? Answer: the
mult. This simple but versatile procedure is
often overlooked, but it can be a terrific aid for
a variety of mixdown tasks.
|Fig. 1. A mult for a lead vocal track is removed from the mix bus and sent pre-fader to a Lexicon LXP Native Reverb plug-in in Digital Performer. The Waves H-EQ Hybrid Equalizer plug-in pre-conditions the mult’s reverb send, rolling off highs.
For the uninitiated, “mult” is jargonistic
shorthand for both the words “multiply” (the
action) and “multiple” (the result). Multing a
track multiplies it by making an exact copy of
it. The result is a mult, or multiple, of the track.
In the analog realm, a mult is created by routing
a track to a patchbay in which the top row of
jacks is half-normalled to the bottom row. Inserting
a patchcord into a top jack creates a new path
for the signal while also preserving its flow to the jack below it. Splitting the signal into two paths
in this manner allows you to process each copy
of the signal differently.
Multing a track inside your DAW is even
easier—just duplicate it. You can then route
and process each of the tracks—original and
In this article, I’ll show you a few ways to use
mults to turbo-charge your mixes and simplify
your workflow. For simplicity’s sake, I’ll assume
you’re mixing inside the box. Ready? Let’s split!
Goose the Level The most basic use of a
mult is to give a track more level—free of clipping—
after it’s already run out of headroom.
In the final stage of mixing, for example, you
might realize that the lead vocal track sounds too quiet. If its level is already close to clipping
and the backing tracks are mixed to perfection,
you’ve got a problem: Either raise the lead vocal
track further and suffer the clipping distortion,
or lower all the backing tracks and skew
your carefully wrought balance. The solution is
to mult (duplicate) the lead vocal track, assign
the mult to an unused mixer channel, and raise
its fader until the vocal sounds loud enough.
(You must have some remaining headroom
on your mix bus in order to accommodate the
extra level.) Be sure to add the same signal
processing to the mult as was applied to the
original track so that they sound the same.
Double-track It To add pizzazz to lead vocals
in the mix, apply pitch-correction (using
Antares Auto-Tune or Celemony Melodyne,
for instance) to its mult but not to the original
track. The dynamically shifting differences
in intonation will create a lush automatic
double-tracking (ADT) effect superior to what
any chorus plug-in can fashion. By riding the
mult’s fader, you can introduce the ADT effect
to different degrees during various sections of
the song. Generous fader boosts during choruses
Pre-condition Effects Say you’ve routed the
lead and background vocals (BVs) to the same
bright hall reverb. The BVs sound beautifully
present, but the lead vocal sounds too bright.
The solution? Kill the lead vocal’s reverb send,
and mult the track. Pull the mult’s fader all the
way down, bus the mult pre-fader to the reverb
via an effects send, and aggressively roll off the
mult’s high frequencies with an EQ plug-in
instantiated pre-fader (see Figure 1). The lead
vocal’s reverb will now sound suitably dark,
while the timbre of the dry (original) lead vocal
track—and that for the BV’s reverb return—
will remain unchanged. This technique is often
referred to as “pre-conditioning” an effect because
it changes how the effect will sound on a
You can also use a mult to transform a compressor
into a vocal de-esser. (Compressors
with fast time constants work best for de-essing.)
The crux is to pre-condition the compressor’s
sidechain. Slap the compressor on the
original vocal track. Mult the vocal, but don’t
add a compressor to the mult. Using a prefader
EQ plug-in on the mult, drastically cut all
frequencies below 5kHz and boost generously above 5kHz. Plunge the mult’s fader all the
way down, and send the mult pre-fader to the
sidechain input for the original vocal track’s
compressor. The sidechain will now “hear” a
horribly bright vocal that exaggerates any sibilance,
but the vocal will sound normal in the
audio path. Set the compressor’s threshold to
initiate compression only when sibilance occurs.
Voilà, the compressor acts like a de-esser!
Simplify Writing Automation A male lead
vocalist will sometimes sound too muddy during
verses when he’s singing near the bottom of his
range and too bright when he’s hitting high notes
in each chorus. You could automate dynamic EQ
changes throughout the song, alternately boosting
and cutting highs as needed. Alternatively,
you could mult the lead vocal track and be done
in a fraction of the time. EQ the original track to
sound brighter (for use during verses) and cut
the mult’s high frequencies (for use during choruses).
Automate the respective channel mutes
for the original track and mult so that the appropriately
EQ’d vocal turns on during each song
section. If you later decide to change the vocal’s
timbre during the chorus, for example, you’ll
only need to make a static change for the mult’s
EQ. Had you not multed the lead vocal track,
you would’ve had to overwrite its dynamic EQ
changes on each and every chorus. Just another
example of how mults save the day!
Michael Cooper (myspace.com/michaelcooperrecording) is a mix and mastering
engineer based in Oregon, and a contributing
editor for Mix magazine.