Mackie 1220I User Manual

24

   Onyx 1220i

This section includes the aux sends and the aux 

returns. Aux sends tap signals off the channels, via the 
aux knobs [29], mix these signals from each channel 
together, then sends them out the aux send jacks [6] 
and FireWire outputs 11 and 12. The aux sends can be 
pre-fader or post-fader (both are post-EQ, but see    
page 38).

Post-fader aux sends can be fed to the inputs of an 

external processor like a reverb or digital delay. From 
there, the outputs of this external processor are fed 
back to the mixer’s aux return jacks [7]. Then these 
signals are sent through the aux return level controls 
[44], and fi nally delivered to the main mix.

So, the original unprocessed “dry” signals go from 

the channels to the main mix, and the processed “wet” 
signals go from the aux returns to the main mix, and 
once mixed together, the dry and wet signals combine to 
create a glorious sound!

Pre-fader aux sends are typically used to provide 

another mix for stage monitors. In this case, the aux  
returns aren’t used to return the signal. Instead, they 
can be used as additional stereo inputs, or not used at 
all.

These knobs provide overall control over the aux send 

levels, just before they are delivered to the aux send 
outputs [6]. These knobs go from off to +15 db when 
turned all the way up.

The aux sends can either be pre or post fader,  

depending on the position of the aux pre/post  
switches [43]. 

This is usually the knob you turn up when the lead 

singer glares at you, points at his stage monitor, and 
sticks his thumb up in the air. (It would follow that if 
the singer stuck his thumb down, you’d turn the knob 
down, but that never happens.)

The aux sends are also sent to FireWire output 11 and 

12 for recording. The levels to FireWire are affected by 
these send controls and the pre/post switch.

The pre/post switches determine whether the aux 

send signal is tapped from the channels before the 
channel level controls (pre-fader) or after (post-fader). 
Having a separate pre/post switch for each aux is a 
super-useful feature as it allows the use of one effects 
processor and one stage monitor chain, at the same 
time. 

For stage monitor work, use pre, so the stage  

monitors do not increase in volume when the channel 
level is adjusted.

For external processors, use post. In this way, the feed 

to external processors will vary with the channel level, 
keeping them in the same ratio, so that the “wet” signal 
level follows the “dry” signal level.

These two controls set the overall level of effects 

received from the stereo aux return 1 and 2 inputs [7]. 
These controls range from off to +10 db of gain when 
fully clockwise, to compensate for low-level effects.

Signals passing through these controls go directly to 

the main mix bus where they are combined with the 
other channels. Alternatively, the aux 2 return can be 
routed to aux 1 send instead, using the rtn to aux 1 
switch [45] described next.

This switch routes the signal from aux return 2 to the 

aux 1 send mix instead of to the main mix bus.

For example, this allows you to use an external effects 

device, like a reverb or delay, exclusively for the  
monitors. When this switch is pushed in, the effects 
signals coming into the aux return 2 jacks are added to 
your aux 1 stage monitor mix. Adjust the effects level 
coming in with the aux 2 return controls [44], until it 
sounds just right in your monitors.

A copy of the aux send 1 and 2 outputs is always  

available via FireWire to send to a computer. The 
FireWire output is affected by the channel aux send and 
master aux send controls. For example, you can set up a 
software effects processor as follows:

• 

Set up an aux send in post mode.

• 

FireWire outputs 11 and 12 are always available 
to send aux send 1 and 2 to your computer.

• 

Pass this through a software effects processor 
or plug-in of your choice.

• 

Return the processed output from the effects 
processor to mixer channels 11 and 12 (input 
switch [23] set to FW 1-2).

• 

Alternatively bring the processed sounds into 
the control room matrix (engage FW 1-2 [36]) 
and add it to the main mix (engage assign to 
main mix [37]).

• 

You can even use the computer as two separate 
independent mono in, stereo out processors. 
Have aux 1 go into one plug-in, and aux 2 go 
into a different one. The stereo outputs of both  
plug-ins are combined back into the stereo 
stream coming back to the mixer.