This is the signal flow in Forte:

signalflow

MIDI Input/Output Ports:  MIDI messages from external sources enter Forte from MIDI input ports.  MIDI Input ports may be virtual input ports created by virtual MIDI output.  See MIDI Input and Output Ports for details on how to configure ports.  Only the EHCo plugin can output MIDI messages to physical MIDI output ports.

MIDI Filters:  Each plugin has a separate MIDI filter for each MIDI input port.  See Plugin MIDI Filtering and Automation for details on how to set up MIDI filters.

Audio Input:  Each instrument module can have a selected audio input mono or stereo channel feeding the instrument plugin.

Audio Output:  Each bus module can be assigned to a selected audio output mono or stereo channel.

Bus Select:  Each instrument module can be assigned to a selected bus for audio output.  More than one instrument can output to the same bus.

Effect Bypass: Effect plugins can be bypassed or not per scene.

Routing in the User Interface

Instrument modules stream audio from a VSTi or DXi instrument plugin through any insert effects and through a mixer to a bus.  A rack has contain many instrument modules and many buses.  Each bus feeds an audio output.

More than one instrument can feed the same bus
More than one bus can feed the same audio output
Each mix level and instrument bus assignment is per-scene and can change for different scenes


Select an Output Bus for an Instrument

instmodule2

Click the bus name on the instrument module to see a bus menu (e.g. "Bus 1" above).  Select a bus from the menu to route the audio to the bus.

Change instrument or bus volume

Both instrument modules and buses have mix volume controls.  You can change either to alter the audio mix.  Adjustments to bus volume affect all instruments that route through the bus while adjustments to instrument volume affect only the instrument (post-insert-effects).

Route buses to audio outputs

 

instmodule

Each bus has an audio output (e.g. "LineOut 1 - LineOut 2" above), which is either a mono or stereo channel of the audio hardware.  Click on the audio output label on the bus to see an audio output menu.  Select an audio output from the menu to route the audio to the audio output.

 

Tip:  With ASIO drivers, only one audio hardware device can be used at a time.  The choice of audio device is determined by the 1st chosen audio output on a bus (in other words, before any buses exist, no audio hardware is enabled.)  When you add an instrument, if there is no bus already, a new one is created with the default audio hardware.  If you wish to use another ASIO device instead, create the bus first by pressing +BUS on the empty rack and determine the audio hardware before you add any instruments.

Advanced Topics

Each instrument's audio chain starts with an audio input (by default "no input") - audio from the input is routed through the instrument.  You can set up an instrument to stream from the audio input device
Adjust audio mix for multi-output plugins (each output individually) - see the Audio Mix tab of the plugin console.
Audio mix can be automated either by MIDI Automation (responding the MIDI input) or a Control Surface
Bus mix can be adjusted using the SceneView mixer