Synchro Arts ReVoice PRO

To a certain extent, ReVoice
PRO might be a ‘one trick pony’,
says ALAN BRANCH – but when
that one trick is spectacularly
performed, you’ll want it for
that one trick alone.

The news that Synchro Arts, the developer behind
the unique and ultimate time saving application
VocAlign, has come up with something new is
worth taking notice of. The company has used its
experience with VocAlign and stepped things up a gear to
produce ReVoice PRO.

ReVoice PRO is a 32/64-bit Mac only, stand alone app
that can align the timing, energy, pitch, and gain of two
mono or stereo audio files in one process. Imagine you
have a main vocal all perfectly in time and tuned, and
you now have to sort out a double track or multi-tracked
harmonies to go with it; or maybe you have several vocal
takes for comping – one guide track
can inform the others. This app will
help sort it in a flash. If you haven’t
got a double track recording it can
even generate one for you. Of course,
ADR and film dubbing scenarios also
come to mind as a prime candidates
for ReVoice (RVP).


ReVoice Pro is a relatively small
download and easy to install.
It’s protected by iLok so a license has
to be obtained through SynchroArts
and deposited on your iLok dongle,
but straightforward enough to get
up and running.

Audio files can simply be
dragged into place and multiple
files will automatically create the extra tracks if needed.
Audio files are placed according to time code position,
which makes exporting and spotting back into the correct
place painless. Alternatively, audio can be transferred
using the RVP Link Audio Suite plug-in within Pro Tools.
Here audio regions in Pro Tools can be sent to the selected
track within RVP, with a click of the capture button.
For Logic, Cubase, and other DAW users, audio can be
exported then dragged into RVP, making sure to use
Broadcast Wave file format to time stamp the audio files.
Seeing as it’s possible to export multiple tracks in most
DAWs, this is relatively easy to do. And the latest news is
that Rewire support has been added as another option
for audio I/O.

Once the audio is within RVP, playback and monitoring
is much like any DAW with simple shortcuts like spacebar
to play, loop control, rewind to return the playhead
back to the original position, as well as options for page
scrolling and time display, double click to scrub, and so on.
Think of it like a mini DAW with its own inbuilt mixer
and s imple level and pan
controls. Waveform views can be
automatically sized or maximised.

In ReVoice Pro the simple
GUI layout of audio tracks are
what VocAlign called ‘Guide’ and
‘Dub’. These two are aligned,
and the resulting process is placed
into an empty output track.
These audio tracks are now
augmented by process lanes.
Here you can place something
called the APT (Audio Performance
Transfer) or Doubler process.

APT can analyse and adjust
the audio for its timing, pitch,
vibrato and level, with various
switchable settings for each section.
Creating an APT or Doubler process
is done via a right click to create, and then choosing
the range you want to process, which can be the audio
selection, play range, or mouse position. You don’t have to
edit or trim the original audio and you can create multiple
APT ranges (even overlapped).

The APT Process window consists of a transfer section
with parameters for adjusting the timing, pitch and level
and a Display/Edit section to show or hide the Energy,
level, pitch and staves. Adjusting the APT timing
is simple enough with a tight to loose slider
supported by a protect transients percentage
adjustment – this helps align vocals either super
tightly, or to keep a natural looseness.

The pitch section is broken into many
parameters – much like you would adjust an
Autotune or Melodyne tracking, there is a pitch
tolerance to set a max amount of pitch change,
a transfer percentage, and an offset to alter the
average pitch. These parameters have some
helpful options with a high pass filter, some pitch
change rules, and an advanced algorithm in case
of any artefacts.

The addition of pitch and level might not
always be needed, so each section here can be
easily be selected, but the inclusion of these
extras means matching two different vocal types,
say female to a male, can be made much easier.
There are pitch options such as “Nearest Octave”,
which will keep the vocal in its natural range, or
“Absolute”, which would tune, say, a male vocal
up to the pitch of a female – but the quality here
would degrade with such a big change.

One really good example Synchro Arts had was
of an audio dub of a film converted from German
to English. Not only could it match the timing,
but also the pitch inflections where, for example,
an onset actor might raise their pitch at the end
of a line whereas a dubbing actor in the studio
might not get the same expression. This small
pitch adjustment can make a huge impact on the
performance delivery in film.

It’s important to select the right area for
processing as noisy artefacts or long silences can
confuse the process.

If, say, there is a breath or an extra word in the
original guide that is not in the dub track, this can
cause problems with the rendered audio trying
to match the two different vocal takes. RVP has a
solution to this with an optional ‘protected area’,
where the APT process will do a blend of the
Guide to Dub track timing. This is a great function
to work around ad lib words and phrases in a
main vocal that don’t exist in the backing vocal.

As well as the APT process, there is a very
useful Doubler process, used in exactly the same
way as APT but operating on just a single track.
It’s possible to generate mono and stereo double
tracks, and extremely believable it is too!

In Use

I used ReVoice PRO on a few album mixes where
I had quite a lot of multi-part double tracks and
harmonies in a J-Pop mix with Japanese double
tracks. The results were fantastic. Exporting files
from Logic was the toughest part, as I discovered
a problem with Wav file’s missing a time stamp.
I had to export from bar 1 and drag the audio to
the start of the bar. Selecting a playback and APT
range is easy enough, then it’s simple to try a few
tight to loose tolerance timing settings to see
which suited the song. I also had to watch out for
the ‘t’ and ‘s’ sounds aligning nicely, so they didn’t
start to stack into big drum-like flam. Once I had
my setting saved as a user preset I could apply
that to any other vocals as well.

The important point here over other software
is that it’s possible to try a loose feel or a tight
feel. If I edited a double track manually to fit a
main vocal it would takes ages to undo it all, or
simply nudge each word to make it loose again.
Aligning vocal takes is not just a case of laying
something back later – some words can be longer,
some earlier, some louder. With ReVoice PRO,
the vocal timing can be changed instantly by
selecting a few different parameters then pressing
the shortcut ‘R’ to render out a result.

The Doubler process uses the same procedure
as an APT creation, but is a single input process
with the ability to generate a mono or stereo
double track in a few seconds. I think this turned
out to be one of my most-used functions with RVP,
as I find a synthesised double track quite hard
to make without some kind of phase problem.
Timing, formant, and vibrato adjustments make
a very believable and usable double track.
Using a main vocal to generate a double track
and removing breaths (don’t want those doubled)
gave a great lift to a bridge, or a chorus part in
the song.


ReVoice PRO is a fantastic piece of well thought
out and puRVPose-made software for dealing
with vocals, although it can be used for any
phrase structured audio. Its ability to swiftly
analyse, compress, expand, tune, and gainchange
from one audio file to another is simply
not possible with anything else. Sound quality
differed depending on how much processing was
being done, but unless you were pitching audio
a lot I found the quality of results to be excellent.

Melodyne Studio can, to a certain extent, do
a lot of the work, but it would still mean manual
editing, as would using Elastic Audio in Pro Tools
or Flex in Logic, and although there are plenty
of editing apps that can do the individual audio
manipulation jobs, no other really matches it for
the complex combination of all.

ReVoice PRO might be a one trick pony to a
certain extent, but if your creative work involves
any kind of vocal aligning it’s second to none, and
certainly a tool I would not want to be without.


GB499.00 (time-limited introductory offer on

Synchro Arts Ltd., 13 Links Road, Epsom, Surrey,
KT17 3PP

+44 (0) 1372 811934


ALAN BRANCH is a freelance
engineer/producer and
ex-member of the On U Sound
Crew. His long list of credits
include Jamiroquai, Beverley
Knight, M People, Simply Red,
Depeche Mode, Shed 7, Sinead
O’ Connor, Bjork, and Sade.