Adventures In Audio with Audio Masterclass
Recording SoftWare for Blind people. Can anybody Please help?

Automated Mixing (part 3)


Mute automation

This is the simplest component of mix automation, but it’s a very powerful
tool. There are a number of mixing consoles available which provide mute automation
but not automation of fader levels. Mute automation is also sometimes available
as an add-on box which can be fitted to any console. It’s a while since
I last saw units of this type advertised, but they are potentially so useful
I’m sure they will make a comeback. Mute automation is simply a way of
turning channels on and off during the mix. You will use this to clean up the
individual tracks so that each track is only unmuted when it has something useful
to contribute to the mix. When the track contains nothing of any musical value
then it only contains noise, and even if that is only the quiet hiss of noise-reduced
analogue tape, then when a number of tracks are mixed together the noise produced
will indeed be noticeable. With mute automation it is possible to conceal noise
very effectively, and also get rid of any unwanted noises that found their way
onto the tape during the recording process. For example, it is common to have
a singer who breaths too loudly, and the sound of the breaths comes too close
to the actual singing to erase them from the multitrack. Mute automation can
deal with such breaths easily, although don’t be too enthusiastic or it
will sound that your singer performed the whole song without breathing at all!
You may say that you can achieve the same thing with noise gates, and cut out
unwanted noise this way. You can, and with the added advantage that you can
tailor the attack and decay to the signal you are processing. But you will find
that a channel of muting is much cheaper than a channel of gating, and also
since you will instruct the system yourself when to mute and unmute, you will
never get any false triggering, which is the scourge of good gating.

The next question is, how does the system know when to mute and unmute? The
answer is that it will synchronise with timecode. If the console has its own
internal muting system, then it is the console that must synchronise. Or in
some cases the muting will be controlled by a conventional MIDI sequencer via
note on and off messages, so it is the sequencer that must synchronise to the
tape. The standard method of synchronisation these days is to stripe the tape
with SMPTE/EBU timecode, and convert that on playback into MIDI timecode (MTC).
All your mutes and unmutes will be logged against MTC and play back at exactly
the right times. There are two ways of entering mute data. One is on a channel
by channel basis, probably using MIDI note on and off messages. The other is
via ‘scenes’ or ‘snapshots’, probably activated by MIDI
program changes. You will develop your own favourite way of working, but there
is probably more flexibility in the channel by channel approach. Something you
will come across very quickly in your automated muting career is the need to
extend or shorten mutes. Suppose you have programmed the system to unmute the
vocal channel for a particular line of the song, just before the first note
starts. Then the producer asks you to release the mute a second earlier to capture
the singer’s intake of breath. This is just one case of extending a mute,
and here the unmute time must be made a little earlier. The full set of possibilities
are these:

  • Mute on earlier
  • Mute on later
  • Mute off earlier
  • Mute off later
  • Mute on and off both earlier
  • Mute on and off both later
  • Mute on earlier and mute off later
  • Mute on later and mute off earlier

I don’t think I’ve missed anything out. The way the automation system
handles mutes for you may make life easier for you, or more difficult. If you
only have one mute button per channel it will toggle the mute on and off, and
you will probably be in a permanent state of confusion since when you are trying
to adjust a mute both you and the computer will be pushing the button! Check
this point out when you look at an automation system. I’ve just been looking
at the Uptown Automation system, which I have to say is not the cheapest around,
and I loved the provision of separate mute on and mute off buttons. It made
shortening or extending mutes a doddle.

David Mellor

Advanced Audio Editing

Advanced Audio Editing

Audio guru Joe Albano is back with an Advanced Audio Editing course in our very popular Audio Concepts series. No matter what DAW you use, watch this course and really accelerate your audio editing chops!

Learn more...

Add comment

David Mellor