Is it possible on Linux and/or Raspbian to take have

two USB audio cards and reference them like:

[dac~ 1 2 3 4]

Where 1,2 belong to soundcard A

and 3,4 belong to a soundcard B?

The reason is that apparently there is massive

price gouging on multichannel USB interfaces.

For example, a Griffin iMic costs $40/USD.

This is 2x2 of crystal clear audio.
So 4x @ 2x2 = 8x8.

So the price for an 8x8 should be $40x4=$160, right?

Or less. Generally you should get a price break

when buying more of the same.

Yet it seems that most 8x8 audio interfaces

are in the range of $600-$900!! (USD).

This seems like 4x to 6x more money than it should be.

So multiple $40 2x2s would be a very cheap alternative

to getting a single 8x8. If it works. (if PD supports it).

PS: in case you don't know, USB 2,0 supports lots of audio!
I was worried about saturating USB bus, and having audio compete for live data from MIDI controllers. But no worries!

I just did the calculation.
Max practical from USB 2.0 is 35 MB/s.
2 channels of 24 bit (3 bytes/sample) audio at 48khz
= 2x3x48k
=288kB/s for 2 channels.

35MB/288kBs= ~122 pairs of audio = 243 total channels possible on USB 2.0. Wow!

Streaming audio may have some overhead, but even if you knock off 1/3 of that, still leaves a lot of room.

USB 1.1 would be 243/40 = 6 total channels. (e.g., 2 in, 4 out).

So you definitely want to be running USB 2.0 if you are running 2in x 2out + midi controllers.

I know lots of people using USB audio on the Raspberry Pi report having problems running at USB2.0 "High Speed" = 480 Mbit/s, and have to set their interface to USB 1.1. (12 Mbits/s). But I am so-far able to run at full USB2.0 speeds with my Pi-2 and the Griffin iMic.

The Pi-2 will DEFINITELY keep up audio-wise, as my latest patch (12-channel flanger) has at least 12 discrete channels of audio simultaneously at one point, but there are many more internal nets

running audio.

I think most complex patches could easily have 24-50 internal nets running audio. Which means even on a Pi-2, PD can definitely do complex stuff and still easily support e.g., 8in x 8out.

So the theory is all there--- has anyone done it?

(Cheap multi-channel audio with PD over USB 2.0
using multiple sound cards... or any other solutions???)

Thanks!

--
May you, and all beings
be happy and free from suffering :)
-- ancient Buddhist Prayer (Metta)