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4.
The Mixing Console
The mixer is just that. We use it to organize our signals going to the
tape machines, to organize what we need to hear back from the tape machines,
to monitor playback from our mixdown DAT, 2-track or other stereo sources,
and to add effects to whatever is needed. In short, it is the heart of the
multi-track studio.
a. Inputs and Outputs
Recording consoles are designed to be connected to multi-track tape machines.
They provide seperate mixer inputs for our sound sources(mics and line inputs)
and the tape returns (signal playback from
the multi-track) and multiple outputs from the mixer to the tape machines
(both as "direct outs" from individual channels and through the "bussing matrix").
In addition, the input channels with a choice of line or
microphone input also offer equalization, effects sends, pan, buss send options
and a fader for volume
on each channel strip.
In-line consoles include the input section and tape return level and pan
on the same physical channel strip. Split console designs have seperate channel strips
for inputs and tape returns, usually with less EQ and effect sends on the
tape returns (the "monitor section").
Semi-pro and home recording gear operates at a -10 level while professional
equipment operates at a +4 level. Without getting too technical, this means
you have to pay attention to the particular input and output levels of your
boxes and how you interconnect them. When it's not right, it often hums or
sounds a little screwed up. It still might work, but it will give you much
less than optimum performance.
To be sure that the sound at the source gets "through the gear and back
to your ear", you need to check the "gain stages" in the "signal path". Distortion
can crop up in several places. Step one is your ear! Make sure the sound at
the source is what you want.
Step two is the microphone or direct output of the guitar, synth or whatever.
In the case of a microphone, the levels must be set carefully to ensure faithful
reproduction of the input. Some mikes have a "pad" switch on them as do most
mixers, to prevent overloading the input level.
Step three is the input channel to the board. The level here must be set
so that the signal doesn't overdrive the channel electronics. Once that is
right, the signal can be sent to tape through the "bussing" matrix (or "group
outs" as they are sometimes called) or the direct out on the channel. Obviously
with multiple signals to one track, they must go through the group outs and
the level to tape is controlled by the group output level.
Generally, in the analog world, very bright sounds get printed a little
lower, to help prevent crosstalk bleed to adjacent tracks. Sharp transient
sounds and low frequency stuff like bass can be printed hot to take advantage
of tape compression. Slamming the tape isn't against the law, but make sure
that's the sound you want. This is only an analog phenomenon, overdriving
digital recorders results in highly unusable audio!
Tape return levels are optimized for direct connection to the machine so
if this has been done correctly, there is only one place left for distortion
to be created... your monitor system. As long as you are aware of how your
speakers and listening enviornment are affecting the sound and you listen
within the volume limits of your amp and speakers, you should have a baseline
for clean signal reproduction. Now, you can introduce distorton at any of
these points in the chain to any effect you prefer.
b. Equalization
"Equalization" is the term used to describe the process of changing the
balance between high and low frequencies. Equalizers allow us to selectively
boost and/or cut specific frequencies or bands of frequencies. "Q" refers
to the width or range around the centered frequency that we are EQing, that
is also affected when we boost or cut. A narrow "Q" would be .2 of an octave,
a wide "Q" would be 3 octaves.
There are many types of equalizers and they get used in many different
ways by different people. In general, "Parametric Equalizers" allow for very
specific effect with adjustable Q and frequency control for each frequency
band. "Graphic Equalizers" feature as many as 31 individual sliders centered
on fixed frequencies. Tube equalizers utilize vacuum tubes in their circuits
as oppossed to transistors ("solid state") and are often preferred for their
warm sound.
All mixers provide some kind of EQ, switchable on or off, in the signal
path. These days semi-pro consoles usually feature a couple of overlapping
bands of semi-parametric EQ on the low-mids(200-2K) and hi-mids(1.5K-7K),
and one EQ each for the low(100 hz) and high(10K) bands with shelving switches
and low-frequency roll-off. Professional consoles offer fully- parametric
designs and more overall flexibility, as you might expect.
Since we can't all afford Neve VR consoles at home, another option for
small studios is outboard equalizers. Get a couple of good ones and insert
them into the signal path and print through them to tape. This will definitely
take your sounds up a notch without totally blowing your college fund.
c. Effect Sends and Returns
There are several ways to get signal to your effects and to hear those
effects back. The easist is the dedicated sends and returns on the mixing
board. Sends can usually be switched between pre and post EQ. Returns generally
have little or no EQ, so if you want to EQ effects, that's one more reason
to have more channels than tape machine tracks. If you have more effects than
sends, repatch the busses as sends or use the direct outs to get into your
other effects.
d. Insert Points and Patchbays
It's really nice to plug everything into the board and not have to mess
with it. This is where patchbays are a necessity and incredible convenience.
Every in and out on the board, all tape machine inputs and returns and all
inputs and returns from your effects are duplicated in the patchbay. Every
channel also has an insert point as well for individually accessing the signal
path. When it's all plugged in, you can change, rearrange and repatch it all
from here.
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