Signal Routing Overview

Signal routing within Software Audio Console is incredibly versatile and correspondingly incredibly complex. However, anyone with some mixing experience can grasp the basics in a short period of time. For more detail, check out the SAC User manual Routing and Signal Flow section.

Input Channel Flow

Input section

Signal routing starts at the FOH channel input section. There are 72 stereo input modules (channels) in Software Audio Console. Physical inputs from the audio interface, virtual instruments, playback/noise generating plugins or virtual inputs from SACLink are assigned to input channels as needed. Audio interface assignments on input channels are from either mono devices or adjacent odd/even stereo pairs. Individual input channels can only be fed from one source, but any input device can be duplicated into as many input channels as necessary.

There are several adjustments available within the input section of each channel:

  • Mixing to mono using one of 6 options
  • Digital attenuation from -inf to +20db
  • Polarity reversal on Left/Right, or Left/Right only
  • Swap Left/Right channels

Digital Splits

Physical input assignment is only made on the FOH mixer. Monitor console channel inputs only allow for digital splits of the channel assigned at FOH. For example, If input channel 1 is your lead vocal on FOH, the lead vocal is fed to input channel 1 on all monitor consoles. You'll never find a different source feeding input channel 1 on any of the monitors instead of the lead vocal.

Where SAC is powerful is in the handling of digital splits. Monitors 1-24 allow selection of the digital split on a per channel basis. All monitor inputs have access to Pre-Attenuator, Post-Attenuator, Post-EQ, Post-Dynamics, Pre-Fade(Post Mute) and Post-Fade splits from the FOH console. Monitors 2-24 also have access to Post-EQ, Post-Dynamics, Pre-Fade(Post Mute) and Post-Fade splits from the Monitor 1 console. Using Pre-Attenuator splits on Monitor 1 allows for complete separation of Monitor and FOH mixing within the same system with physical gain being the only shared attribute.

Input Channel Processing

By default signal passes from the EQ to the Dynamics section, then on to the Pre-Fx patch point. Individual channels have an option to process the Pre-Fx plugins before the EQ/Dynamics as well as an option to process the Dynamics section prior to the EQ. These options are found in the Mixer Menu.


Each input channel has a 5 band parametric EQ plus low-cut and high-cut filters. Gain on each band is +/-15db. Bandwidth varies from 1/10th octave through 3 octaves. Frequency sweeps from 40Hz through 15KHz. The low/high-cut filters are 12db/octave and sweep from 40Hz through 15KHz.


Each input channel has both a compressor and gate section. The key data shared between both sections is either from itself or the pre-attenuation input from any other channel. The key data can be processed with both a low-cut and high-cut filter identical in function to those in the EQ section.
The gate section has adjustments for threshold, attack, release and floor (maximum attenuation). The gate also has a reverse switch allowing it to close when signal exceeds the threshold level and open when it falls below. This can be useful in ducking the signal beneath another input channel.
The compressor section has adjustments for threshold, ratio, attack and release.
The gain adjustment affects the output signal from the gate and compressor section.
The gain reduction meter shows any gain reduction occurring in either the gate or compressor section.

Pre-Fade Fx

If not changed, the Pre-Fade Fx patch point is next in the signal chain. The entire chain may be bypassed or individual plugins can be bypassed. Plugins are processed in order from top to bottom of the list. Plugins can be any SAW/SAC native plugin, Direct-X or VST plugin that reports zero latency. Plugins that add any latency are automatically disabled.

Aux Sends

Each of the 25 mixing consoles have 6 stereo auxes selectable between pre-fade and post-fade sources. The pre-fade source is pre-fade/pan and post-mute. By default, the post-fade aux panning follows the channel panning. In addition there is also a pan control for each aux send. The aux sends are routed to the corresponding aux master located above the return section on the 6 return channels.
One paradigm shift to note. If you're used to using aux sends for monitor mixing you'll probably want to break that habit in SAC. Monitor consoles replace that functionality while adding much more processing ability to each monitor mix. Monitor consoles also allow easier access to controlling channel levels into a monitor mix than using the aux send controls. If you're used to digital consoles with sends-on-faders, manipulation of monitor levels within SAC is analogous to that functionality.
Auxes in SAC are more often reserved for effects processing, though they are not limited to that either. They can also be handily used as a variable bus or as an additional submix prior to routing through another output bus. Currently, they're also the only way to pass a submixed signal from FOH to the monitor mixers.

Solo Button

When the solo buss is set to pre-fade on the Mixer menu the solo signal is sourced next and prior to panning, fader attenuation or the Post-Fade Fx processing. When set to post-fade, the signal is sourced after all additional processing including the Post-Fade Fx patch point. By right-clicking the solo button, attenuation can be additionally applied to the signal passed to the solo buss.

Mute Button

The mute stage is next in line. With the exception of pre-fade auxes, all signals prior to the mute button are unaffected and all signals after it are muted. The mute button can be set on both the FOH and Monitor 1 mixer to latch all mutes on the mixers below them. If set the FOH will also mute Monitors 1-24 and Monitor 1 will mute Monitor 2-24 but not FOH.

Channel Fader

Next up, the signal is attenuated by the channel fader.


Signal passes to the pan control where it is panned.


After the signal is attenuated by the fader the result is passed to the post-fade fx patch point.

Surround Panning

Output Assignment

Finally the signal is routed to the selected stereo output busses. By default Output 1 is selected on all channels, though if no output is selected the signal is not routed anywhere.

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