Creating Audio Application with two AudioAppComponent instances?

Hi all,

I want to build a simple macOS app to manipulate (in my case controlling the audio level of) two different CoreAudio devices. I thought about creating two child AudioAppComponent class instances in the MainComponent class, but the AudioAppComponent Class Reference says

An application should only create one global instance of this object and multiple classes should not inherit from this.

Has anybody an idea how I could create something like that?