I think the preference on macOS is to let the system do it via Aggregate Device. I'm not sure if PortAudio handles this as well on the platform. It might work but I'm sure using Audio MIDI Setup to do it is better.

On Apr 13, 2024, at 12:00 PM, pd-dev-request@lists.iem.at wrote:

Message: 1
Date: Fri, 12 Apr 2024 23:11:41 +0200
From: Max <abonnements@revolwear.com>
To: pd-dev@lists.iem.at
Subject: Re: [PD-dev] Multiple audio devices?
Message-ID: <4d9ef88a-002e-46cc-9bea-d7a4a5cc27bb@revolwear.com>
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On 12.04.24 21:59, Alexandre Torres Porres wrote:
And I wonder why we can't do this on mac. It would be cool and would 
help me a lot

I think the OS can do it on Mac (over a decade ago that I've used Macs, 
but back then it was called "aggregate device" and you set up such meta 
device which is composed of multiple soundcards. It exposes then the sum 
of the inputs/outputs to the system).

I have no idea about the rationale not to include that function in Pd on 
Mac, but I assume it's better if the OS is doing it. From what I 
understood Apple is doing resampling anyway to compensate for clock 
drifts, just like pipewire does on Linux.

https://support.apple.com/en-us/102171

--------
Dan Wilcox
danomatika.com
robotcowboy.com