Main reason I mention this one is because ASIOLink Pro isn’t supported anymore as far as I know. It works great now, but will Windows 11 and beyond eventually ‘break’ it? Jack is maintained, updated on a pretty regular basis, and is open-source.
Not my favorite to set-up (ASIOLink Pro was just easier, and rock solid on my hardware), but it DOES WORK, and it’s not hard really. Set it up well, and it purrs…allowing the routing possibilities between ASIO apps on the same machine. I’ve noticed the GUI is MUCH better now than it was years ago when I first tried it.
Why? For me, it outperforms any of the other simple WDM > ASIO bridges I’ve tried so far (including the one that ships with Steinberg hosts), and quite a lot of people use ASIO hosts on machines with devices that do not have native ASIO drivers. It’s actually configurable, and allows aggregating inputs. Could use it to aggregate outputs as well, but not advisable unless you have a way to match things to use the same clock.
Good question, but it is what it is. Part of the reason they don’t open it up in terms of aggregating multiple devices, is the clock problem. Technically, it’s against the protocol rules to aggregate multiple audio cards that are not designed to share a common clock, and ship with drivers and such to set it all up properly. Cards that can do this ship with drivers that typically are limited to specific models or chip-sets that are designed to sync-up and work together.
If every joe out there starts trying to aggregate audio cards, all on their own clocks, without understanding the potential pitfalls (and jumping through unsupported/unofficial hoops)…people will COMPLAIN that their outputs aren’t in sync and ‘drift apart’. So, it’s up to device makers to ship drivers with the features they intend to support. If a device isn’t designed to slave to external clocks, or share clocks…then the ‘system’ is not going to work properly (the devices will get out of sync over time).
In the windows world, what would you recommend that’s better than ASIO? Cards do exist that can aggregate properly, and they tend ship with good drivers that hook into ASIO properly. A few cards can be locked to an external clock of some kind and share it (via special coax ports, or light-pipe ports, etc.) There’s also the option to just replace the ‘multiple-card’ layout with a single device that has the required number of inputs/outputs. There’s also the option to use hard analog patch chords (introduces an analogue stage that might not be so great, but it’d work for basic home studio people on a budget).
As for a given Steinberg branded audio interface, and whatever ‘loopback’ feature you’re about…I do understand your disappointment if it’s not doing what you purchased it to do. Still…the question comes to mind…what card in the same class and price-range fits your requirements?
I’m not aware of any/many that allow aggregating different makes/brands/models of audio interfaces ‘out of the box’. It’s going to require hacks if the cards were not designed to go together, and include the drivers to do it.