Choosing a Mixer
Critical Mixer Features
Lets Get the Lingo straight.
terms will let you talk about
mixers. They will help you compare the features of the boards you see. They
apply to all types of mixers, even the software mixers in your sequencer.
So these terms are important. Make sure you have a solid grasp on
them, even if you are going mixerless.
is a pan pot?
A pan pot, or sometimes called pan knob is short for
"panoramic potentiometer". It allows you to place the signal anywhere
in the stereo field, from extreme left to extreme right.
What are a mute/solo buttons?
The mute button
silences the audio on a channel so you can hear other stuff in
the mix. A solo button silences everything except the signal
on a channel so you can hear the channel in isolation
What are routing buttons?
These are switches
that switch the audio signal down the pathway to the busses. You might
think of them as an output selector for now. If you
press the 3-4 button and pan all the way left,
the signal goes out bus out 3. If you press the 1-2 button and pan
all the way right, the signal only goes out bus out 2. If you press
1-2, 3-4, and L-R and pan center the signal goes out all 6 outputs.
What is a fader?
is a sliding level control that can be used to vary the loudness of any
mixer channel. The name comes from "fading in" and "fading out" tracks.
Note the little "infinity" symbol at the bottom.
Infinity means "zero" in mixer-speak. See the heavy line next to the
solo button? That is the marker for 0dbvu, or sometimes
called the "nominal" or normal level. What it means is at that
point the signal that exits the fader is the same
as the signal that entered the fader. If you lower the fader
from that point you attenuate (reduce) the signal.
If you raise the fader from that point you add gain (or
boost) the signal.
From top to bottom you see a pan pot, mute button,
solo button, and 3 routing buttons. The fader is the sliding control. The
pic is of a 4 bus
What is a channel?
A channel is basically an audio input that goes to a
fader. A typical mixer channel may have an input selector for choosing
mic or line signals, a trim knob for adjusting the input level, dedicated
EQ (equalization) controls to alter the bass, midrange and treble bands
of the signal. A channel usually has sends which send part of
the signal to an effects unit (or other destination). Finally a channel
may have a bus selector switch (the routing buttons we saw before), which
switches the channel output to a bus.
What's a Bus?
A bus is a fader with its own dedicated output.
Said differently, a bus is a major pathway from all channels to a single
fader connected to an output. You can take everything going to that
fader out of the mixer where you can send it to another piece (or rack)
of gear. You can also bring the signal back in to the mixer on spare channels.
On mixers with busses, there are routing buttons on each channel that lets
you route the whole signal to one of the busses. The Main bus is often
called the L/R bus. Other busses are often grouped in pairs, like the 1-2
bus, 3-4 bus, as in our example above. There may also be another switch
that lets you route these bus faders to the Master fader.
Typical uses of busses are to send a track or groups
of tracks to a digital multitrack, or to a soundcard or audio interface.
Yet you can also be very creative with them, such as sending them to samplers,
grooveboxs with analog inputs, surround encoders, separate compressors and
more. Some busses may have inserts. These are nice as they
let you return the external signal back to the mixer without eating up
The faders at the bottom right side are bus faders. The
switches above the channel faders switch the channel to one of the
What is a channel insert?
An insert is a pathway out and then back into a single fader.
You use it to patch in an external piece of gear that only affects that
one channel. Typical uses of inserts are patching compressors, outboard
EQs, exciters, pedals, multi-track recorder i/o, and FX boxes. Lots of
people route channel inserts to a patchbay where they can plug in
various devices conveniently. We are talking Hardware plugins here. On a
well featured mixer, there are inserts on individual channels, buses and
the master fader.
You should be getting a sense that there is no one way to set up a
mixer. Its really just a matrix of audio pathways that can be used to
build up a sculpture of sound that is called a mix.
What is "In-Line Monitoring"
In line monitoring is a feature on some recording consoles,
like the Mackie 24-8 or Behringer MX900 and Alesis Studio 32 that allows
each channel strip to have 2 separate inputs, with a switch that sends
either input to the fader on that channel. Usually, the input that is
not selected goes to a knob on that channel where it can be turned up
and be "monitored" on one of the busses. This is how 16 channel boards
can have 32 inputs at mixdown. This is sometimes called a "Mix B"
feature. The input for the Mix B channel is the "tape in" jack. On this
kind of mixer there is a tape in on every channel.
"Balanced" ins and outs.
A mixer with balanced inputs and outputs allows you to
connect gear that is balanced with XLR or 1/4 inch TRS cables. This
essentially allows you to run cables in greater lengths, even to the
next room, and not pick up hum or noise. Mixers with unbalanced ins and
outs require shorter cable runs, and use 1/4 inch TS cables or RCA
jacks. More on cables. If your audio interface has balanced inputs and
outputs you may want a mixer with balanced inputs and outputs. Most
mixers with balanced inputs will accept unbalanced cables too. So if you
are using a soundcard with unbalanced RCAs you can still use a mixer
with balanced inputs most of the time.
What's a Send and Return?
A send is a major audio path that goes out of the mixer. On each
channel, ideally, there is a knob for each send so you can direct variable
amounts of that channel to the pathway. This can function as a
separate monitor mix if you are doing a live show, where every
player has a monitor in front of them. Or in the recording situation,
the send typically goes to an effects unit. See the 4 turquoise
knobs in the pic? Those are sends. And in my system, each
knob goes to a separate hardware device. The signal is brought back
to the mixer by the returns, then is added to the main
Creatively speaking, a send is a submix, do with
it what you want. You don't have to bring back the sends to their
returns. You can bring them back to an empty channel where you can continue
to process with EQ, or to a bus fader if you want. You can
use the returns like any other line input, patching in synths, other
mixers, computer soundcards even your cd player, turntables, TV whatever.
Time Out: What
is the difference between a "live" console and a "recording"
To really understand how these
terms came into being you have to go back to the days when multi-track
reel to reel recorders ruled. Each channel of the recording
mixer had to have a direct path to the recorder, called
a "direct out". Many recording consoles had a "Mix B"
as well, which allowed the band's instruments and the recorder
to share the same fader so you could press a button an monitor
what was exactly being printed on the tape. The early
live mixers did not have these features. Mix B is still
a useful feature today, particularly if you have a 24 track
digital recorder. You'll find it on the Behringer MX9000,
Mackie 8 bus series, to name two.
A live console may omit
the direct outs and usually won't have a Mix B. However,
they will have busses like the recording mixer and will more
than likely have inserts as well. Many Live consoles will
have global EQ, an EQ that affects the whole mix, as well as
channel EQ. Recording boards typically won't have global
eq. Finally, a live console may have more sends on it.
Sends are used live to send signals to stage monitors.
In the studio, they are typically sent to FX boxes. They
work the same way though.
OK, the all important
question: Can you
use a live console for recording to your DAW?
Of course! Use the busses to get isolated signal to your DAW,
soundcard, or audio interface. They work the same way.
Or if you want, use the inserts to connect to the DAW with unbalanced
cables. Just shut off the global EQ.
Rather than worry about the
archaic category name of the mixer, focus on whether it has
all the ins and outs you need. Does it have enough busses?
Do you need direct outs? How many sends and returns, preamps
do you need? How is phantom power implemented? Are all
the connections balanced? Which are not? Those are the
questions to ask.
Don't Buy the Wrong Mixer!
Primer on Analog Mixers:
A 2+2 bus mixer typically
has both main stereo outs and an "alt 3-4" or "subgroups
out" for connecting to a soundcard. These are fine for
using a computer as a recorder. Stereo mixers
do not have this bus. I do not recommend them for computer
multi-track recording A 4-bus mixer typically
has main stereo outs plus two alt or subgroup
busses. These are great if you have a soundcard or audio
interface with more than 2 inputs. However,
some manufacturers call their
2+2 mixer 4-bus mixers because they count the main outs
as 2 and the alt bus as two more. So
be careful you might find some 2+2 mixers lurking the
in zzounds 4-bus category.
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More Articles by Tweak on Mixing and Mixers
Mixing and Mastering
Choosing a Mixer for your Studio
Understanding your Mixer
Classic Analog Mixers
How to Hookup a Mixer
Guide to Control Surfaces
How to use EQ
How to Use a Compressor
Using Pan Controls
The Perfect Mix
Review of the UAD 4k Processors
Mixing on a Virtual Console
Tascam DM3200 Resource
Mackie 8 bus Console Resources
Elements of Mastering
Mixer catalog List