On the Falcon Homepage, UVI writes:

HD SURROUND CAPABLE
Native support for channel configurations from Mono to 10.2 and sample rates to 192 kHz and beyond. Whatever project requirements you encounter, rest assured Falcon can handle it.

It was one of of the things that I looked forward to, since I enjoy surround sound a lot and from that blurb expected rather deep surround support, something most instruments are lacking today.

The current documentation for Falcon (as of version 1.1.4) doesn’t even contain the word “surround” and only mentions things like “5.1” and “multi-channel” for the Gain Matrix effect. So you’re on your own…

What it can do (as of 1.1.4) is:

  • Playing back surround samples up to 10.2 in it’s sample oscillators, including the grain, stretch and slice oscillators.
  • There is a fixed kind of panning if you use stereo material (not with surround samples). It works on the keygroup level and basically allows you to rotate the stereo signal around, but you have no finer control over width etc.
    But using a ramp LFO, this allows you to rotate a source around continuously or have an envelope move the sound of each note individually.
    One of the developers described it on KVR like this (https://www.kvraudio.com/forum/viewtopic.php?f=1&t=449200&p=6282438#p6282438):

    “We do have surround panning when going from stereo to 10.2, it’s not simple to explain. Here’s basically how it works: stereo input is simulated in surround by 2 virtual speakers at -45° and +45° on the left and right of the listener, the pan control becomes a rotation angle between -180 and 180°. The rotated sound-field is distributed on the output speakers by first panning each virtual speaker on a quad setup, then by recursively splitting front, rear, left and right sides by adding new in between speakers according to the output format.”

  • Originally, right after the initial release, you could not set the Falcon VST to a surround mode manually, it did only work in a DAW that explicitly does have surround tracks, the format of which Falcon then would use.
    But this left out all stereo- and less traditional, node based DAWs that either only support surround in the mixing stage or simply do not announce the number of channels they support, for instance nodebased DAWs like Plogue Bidule, Usine Hollyhock etc.
    That has changed in the meantime though, you can now set a channel configuration manually like in the standalone version – but only one for all instances of Falcon. Other VSTs offer more flexibility there (like different plugin versions for different channel modes) and I hope UVI will also evolve this part further.

What Falcon does not have is:

  • Surround support on the oscillator level, like every grain being sent to a different location in the panorama or other such more advanced uses of surround.
  • A surround panner that allows more than simple rotation.
  • A real surround mixer.
  • Advanced control over centre and LFE (only the Gain Matrix is available and it’s not the most intuitive tool).
  • Specific surround effects.
  • Surround works only on the main output, not on the 16 additional outputs you can use for programs.
  • You can’t setup your own output scheme in the stereo version using multiple outputs, since each program can only go to one of those 17 outputs, the mixer also does not allow to send to other outputs. The only thing you can do is having the same program twice (or more often) and send each one to a dedicated out, then automate those accordingly…

Or in short: You can use Falcon as a capable surround sampler and for basic panning of all it’s mono and stereo oscillators in the surround field, but it does not offer advanced capabilities for surround sound design or -mixing.