Hi,
If you only use one instance of Analog Lab, then you can only have two sounds, when you use Multis presets.
You can set seperate midi channels for the sounds.
You can also set a keyboard range for each sound so the sound depend on the midi notes you play, even when the sounds are on the same midi channel.
Have a look in the manual section "4.5. Keyboard Settings".
Also read about Multis and Edit Preset in the manual.
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If you use a DAW or a host, then the functionality also depend on the DAW. You might need two tracks to send two different midi channels to one Analog Lab instance loaded on both tracks.
You can also use multiple instances of Analog Lab. Then you many times don't have to use Multis presets, even if you can.
How this can work in example also depend on how you can work with midi channels with your controllers, and in a host if you use one.
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Have a look in the manual section "3.3.1. Settings Tab". For standalone midi channel setting.
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In all case, then keep in mind, that some presets are made in applications that can have different midi channels set internally for different sounds or keyboard manuals. This midi channels can afaik at the time being not be changed without owning the individual full application in question. This can have an impact on how you plan your work.
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It's really something you have to work with, and find out, what you can and what you can't do.
I have never used multiple controllers for an application. But it should work. At least if they show up in audio and midi settings. Not sure you can use two of the same type of controllers. I think it should be possible.