MACKIE ONYX 1640I - Manual (Page 15)

Owner's Manual 15
Another way to consider low-cut’s function
is that it actually adds fl exibility during live
performances. With the addition of low-cut,
you can safely use low equalization on vocals.
Many times, bass shelving EQ can really benefi t voices.
Trouble is, adding low EQ also boosts stage rumble, mic
handling clunks and breath pops from way-down low.
Applying low-cut removes all those problems, so you can
add low EQ without blowing your subwoofers.
24. INPUT (LINE or FW 1-16)
All 16 channels may be fed either from the mic/line
inputs, or by up to 16 outputs from a computer via
FireWire. This switch lets you choose (on a per-channel
basis) whether the channel is accepting a mic/line input
or a FireWire output stream from your DAW.
While tracking, you will likely want all of these
switches in the "up" position so you can hear the inputs.
When overdubbing, you will likely want whichever
tracks are already recorded to the DAW to stream back
into the board (e.g. drums on 1-8 while overdubbing
bass on channel 9, so you'll want the input switches on
channels 1-8 in the FW position). And when you are
ready for full analog mixdown, you will probably want all
of these switches in the "down" position so you can do
a full 16-channel "tape style" mix - the way mixing was
meant to be!
25. HI-Z SWITCH (Chs. 1 and 2 only)
Engage this switch if you want to connect guitars
directly to the 1/4" line inputs of channels 1 or 2.
Without this switch, you need to use a DI box fi rst,
before connecting guitars. If these switches are not
pressed in, guitars will not sound good, particularly the
high frequency response.
Plugging a guitar into a lower-impedance
line-level input can result in the loss of high
frequencies, causing an unnatural and dull
sound. Normally, you must use a direct box
between a guitar and a mixer’s input, which serves to
convert the impedance of the guitar from high to low.
The hi-z inputs on channels 1 and 2 make the need for
a direct box unnecessary. However: The hi-z inputs are
unbalanced (when the switch is in), so if you’re doing a
live show and running a long cord between the
instrument and the mixer (say over 25 or 30 feet), it is
best to use a direct box with a balanced output to avoid
picking up noise over the length of the cord.
26. GAIN CONTROL
If you haven’t already, please read the level-setting
procedure on page 3.
The gain knobs adjust the input sensitivity of the mic
and line inputs. This allows signals from the outside
world to be adjusted to run through each channel at
optimal internal operating levels.
If the signal originates through the mic XLR jack,
there will be 0 dB of gain with the knob fully down,
ramping to 60 dB of gain fully up.
Through the 1⁄4" line input of all 16 channels, there is
20 dB of attenuation fully down and 40 dB of gain fully
up, with unity gain "U" at 11:00.
This 20 dB of attenuation can be very handy when you
are inserting a hot signal, or when you want to add EQ
gain, or both. Without this “virtual pad,” there is more
chance of channel clipping.
27. SEND FIREWIRE PRE/POST
Each channel of the mixer can send a FireWire output
to your computer or DAW. The FireWire output from
each channel can be tapped before (pre) or after (post)
the channel EQ. (The output is always pre-fader.)
If you want the mixer EQ to affect the FireWire
recording, then set this switch to post. This is useful
in recording channels in a studio (where the recording
includes the benefi cial effect of our Perkins EQ).
If you would rather record the straight signals from a
live performance, and EQ them later in your DAW, then
set this switch to pre. This is good for live work, where
you may have added EQ to adjust for the room, and yet
not want this added to your recording.
CHANNEL EQUALIZATION (EQ)
All 16 channels have 4-band EQ with shelving high,
shelving low, and peaking hi-mid and peaking lo-mid
with adjustable mid frequency.
Shelving means that the circuitry boosts or cuts all
frequencies past the specifi ed frequency. For example,
the low EQ boosts bass frequencies below 80 Hz and
continuing down to the lowest note you never heard.
Peaking means that certain frequencies form a “hill”
around the center frequency.
With too much EQ, you can really upset
things. We’ve designed a lot of boost and cut
into each equalizer circuit because we know
that everyone will occasionally need that. But if you max
the EQ on every channel, you’ll get mix mush. Equalize
subtly and use the left sides of the knobs (cut), as well
as the right (boost). If you fi nd yourself repeatedly using
a lot of boost or cut, consider altering the sound source,
such as placing a mic differently, trying a different kind
of mic, a different vocalist, changing the strings, or
gargling.