Audiobus is an app available on the App Store and also a standard by which audio applications can connect to each other. If you own a copy of Audiobus you can use Quincy in conjuction with it to do some pretty cool things.
To use Quincy in Audiobus you select it on the left side as input. Once the app's icon appears you can and should use it to switch to Quincy when needed. Once designated as input source Quincy will continue any playback even though it is not the forefront application.
Due to its demands on the processor which are considerably higher than that of any instrument or effect, it is a good idea to run Quincy at the bottom of the stack. That means adding it first before any other instruments.
Quincy displays the Audiobus toolbar to the right. Again - when Audiobus is active, the toolbar icons should be used to switch between apps.
In other apps Quincy displays three icons in the Audiobus toolbar. One (top) is the standard app icon used to toggle the auxiliary icons, second (middle) is the app standard switch icon and last (bottom) is the play/reset icon. The latter can be used to start and reset Quincy in other applications. This works exactly the same way as the transport controls in Quincy.
Audiobus allows many different workflows. To successfully integrate Quincy into any of them there are a couple of things to keep in mind. Quincy does not implement any artificial caps, so it is entirely possible to generate documents that may quite at the edge of a device's capabilities. That can lead to crackle and/or complete audio outage even when running Quincy by itself. A document like that is not a good candidate for Audiobus as additional apps will only increase the processor load. Particularly on older devices it is helpful to keep an eye on the activity monitor in the HUD. In cases where a document is too demanding on the processor for live Audiobus integration there is still the option of recording Quincy separately and using the recording. Please make sure to read the Audiobus paragraph in the Performance chapter.
App switching while Quincy is in background mode may lead to brief interruptions in the audio stream depending on the device and composition. A good workaround is to start playback in the final application of the stack.
NOTE: To maximize available processor utilization for audio several graphic effects are automatically disabled when Quincy is in background mode. These are Generations, Color Mash and Stars.
Audiobus integration took a tremendous effort and affords several new ways of getting audio into other apps. That said Quincy may not be an ideal candidate for all workflows - in particular where live app switching is required. Where there are no issues on iPhones in general, performance varies a lot on iPads with the newer ones doing much better than older generations. This is to be expected with an application as complex as Quincy. So for best results try to keep grids really small and voices down.