Recording - September 2016 - 41

Using these formats, the timing information of the audio is kept intact, and
the tracks are properly represented as
mono or stereo. Some applications will
export volume and pan information to
an OMF/AAF file, so it would be best
for the provider to set each track's volume to 0 dB and pan to center before
exporting, just in case. Remember,
you're trying for a clean slate to begin
mixing from.
Another consideration is crossfades.
Depending on the software in use on
either end, they may or may not be represented correctly in the OMF file. Also, disabled or archived tracks are not included;
neither is any tempo information. When
requesting an OMF or AAF file, also ask
for a text file that lists the sample rate and
bit depth of the audio, the starting tempo
and any tempo changes, and any other
details deemed pertinent.
Getting you an OMF or AAF file
shouldn't take an engineer hours of
work, it's pretty much a matter of choosing File > Save As or File > Export. But
there is a certain level of frustration when
using OMF and AAF. Some feel they just
don't function as intended. Results are hit
or miss, and it may take some back and
forth to get it right, which does end up to
be time-consuming.

up properly when loading into another
system. An alternate way to accomplish
this is by using Broadcast Wave Files
(BWF). The BWF format contains timing
information. So, if instead of highlighting
from the beginning of the song, you
were to highlight an audio clip that
starts at measure 16 and export it as a
Broadcast Wave, the resulting wave file
would load into any DAW beginning at
measure 16 (given a correct tempo setting). This may or may not be easier for
an engineer delivering tracks to you,
and is an option to be aware of.
Version 2 of the Broadcast Wave file
specification was released in 2011. It
incorporates loudness metadata (for
satellite, terrestrial, and internet broadcast uses), so when using Broadcast
Wave files for mixing, it's best to stick
with Version 0 or 1.
MIDI
Where an engineer will have to spend
a bit of time is if the project contains MIDI
tracks, turning them into audio. Some
time, yes, but not "hours of re-work"!
There are two scenarios here: MIDI
tracks triggering an external device and
MIDI tracks triggering a software plug-in
(a virtual instrument). In the latter case,
the engineer will use the DAW to create

ated much more quickly. Once the MIDI
data exists as audio tracks, those tracks
can be exported as described above.
Stems and comps
There are cases where, instead of
individual tracks, a stem may be more
desirable to you as mix engineer. A stem
is a group of audio tracks mixed down
to stereo. Where you might find this
most useful is in the case of background
vocals. Backing vocal parts are often
made up of many tracks. Multiple harmony notes are doubled or tripled, and
the track count quickly adds up. If your
client is happy with the way these parts
are sounding in his scratch mix, then
have the engineer provide a dry stem!
Working with a stem can be handy
for any grouping of instruments,
although in the case of drums and percussion it's best not to use a stem.
Having these as individual instruments
gives you the most control over the mix.
Similar to a stem is the vocal comp
track. This is a single track made up from
portions of multiple vocal takes. I don't see
why not to use a vocal comp track, if the
artist is happy with the way it is sounding.
You could always request alternate takes if
you hear something in the lead vocal that
can't be fixed with your tools.

What should an artist provide to you as a mix engineer,
when you're being asked to mix an entire song that was recorded
either on their home setup or at a local studio where they live?
Raw tracks
To get a total clean slate to begin mixing from, the engineer or artist can manually export each track as a WAV or
AIFF file. This is the method I prefer; it
isn't difficult or time-consuming either, as
most DAW programs have a batch
export feature.
For example, in the version of
Cakewalk SONAR that I use, I simply
select my mono tracks, making sure all
track data from the beginning to the end
of the song is highlighted. I choose File
> Export > Audio. From there I choose
the "Raw Tracks, No Automation/FX"
preset. I set the channel format to mono
and the sample rate/bit depth to match
my project. After exporting the mono
tracks in this way, I go back and do the
same for the stereo tracks. In five minutes, I've exported all audio in a format
suitable for mixing at another studio!
Broadcast Wave Files
The reason for highlighting all track
data from the beginning to the end of
the song is to make sure everything lines

an audio track from the MIDI data. This
is a common feature in DAWs; depending on the program this feature may be
called mixdown, export, freeze, render,
bounce, or something similar. Before
converting the MIDI data to audio, the
volume of the soft synth should be adjusted so that a healthy level (but not clipping) is being provided. This is also
when decisions about effects in use within the sound preset of the virtual instrument must be made. If the effect is integral to the sound and character of the
song, then it should stay. Otherwise I
would have the engineer not include
effects when mixing down MIDI tracks.
MIDI tracks controlling external devices
are recorded to audio in the same way
any external device (guitar, microphone)
is. Set up a track to record to in the
DAW and feed the external sound source
to this track. I'm sure this is a familiar
procedure for an engineer using external
modules and a mixing board.
Mixing down external devices is of
course done in real time, but virtual
instrument "freeze" audio tracks are cre-

Practice makes perfect
Successfully providing all the parts
that make up a song for mixing at another studio comes down to knowing your
tools. I feel the engineer in my story
needed to train on this, taking some time
to learn his tools better. He wasn't being
mean, but he was showing off what he
didn't know about what his DAW could
do for him in this case.
Does your software export to OMF or
AAF? Give it a try. Save a test song as
an OMF file and open it up, see what
the results are. Find your DAW's batch
export feature and learn what it takes to
easily export all the audio tracks in a
song as raw tracks. If you've never
mixed down a MIDI virtual instrument
track to audio, do so in your next project. What you learn will come in handy
when requesting tracks from or providing tracks to another studio!
When not custom songwriting for the
educational market, Michael Nickolas
(nickolas@recordingmag.com) creates
content for music libraries.
RECORDING SEPTEMBER 2016

Table of Contents for the Digital Edition of Recording - September 2016