Inter-app audio routing is - as you can imagine - something we take seriously here at Cycling ‘74. For a while, we were supporting the Soundflower program/driver setup, which allowed you to create virtual audio streams and capture/route them as needed. It was a great tool for creative audio folk, but it was also fraught with issues (mainly due to changes in the underlying operating system technologies) - and became impossible for us to support. Rogue Amoeba took over support for a while, then passed it back to its original author - Matt Ingalls - who now provides the source on his Github site.
What It Is
Rogue Amoeba also has a long history of creative audio tooling, and has extended the audio routing concept with a new product: Loopback. Rather than acting like a audio pipeline, Loopback is a driver-level system that can work with specific audio-enabled packages, turning the audio I/O pipeline into a stream that is mighty easy to capture, use and monitor.
There is a Loopback application, which allows you to set up virtual drivers - each one can be set up for specific source applications, monitoring applications and channel routings.
Once the setup is complete, each of the virtual drivers shows up as an individual audio source in Mac CoreAudio applications.
From there, you are just running per normal. Internal differences in streams are managed by Loopback, and I’ve not found a situation where it was confused. It’s a solid piece of engineering, and hasn’t caused any problems either in the routing or at the operating system level.
How Do I Use It?
If you can’t imagine a use for Loopback (and I’m actually betting you already have…), you can think of it as a patchbay for your studio, but housed inside your computer. You can shoot audio throughout your system, and record/effect/mangle with almost any program that can speak Mac audio. It holds a few important positions on my laptop: I use it for recording Skype conversations, for quickly piping audio from Max to my recording software, or for snagging police calls from my copy of iScan (a police-and-fire scanner package available on the App Store). It’s a great way to capture anything, and since it avoids entanglement with other software packages, it’s not as invasive as Soundflower was.
Conclusion
Some pieces of software stand proudly on your desktop screen, and they are first-click items every time you turn on your system. But it is often the subtle, less-visible software products that really make your system hum, and Loopback is one of those for me. Worth every cent, and part of my everyday quick-and-effective toolkit.
Loopback - US$99, or bundled with Audio Hijack for $130 by Rogue Amoeba
Would have been nice to seen a comparison to Jack Audio, since Jack is powerful, free and open source. It's what I typically use in these situations. It has a command line interface (which can be super handy) and it runs on windows, linux, and mac. It's honestly a bit weird to see an advertisement here for an app that costs 100 dollars without even mentioning a free alternative that probably is the industry standard.
Well, Jack is hardly industry standard. Most musicians have probably never even heard of it. It’s also a PITA to setup and configure. I’ve been using Loopback on tour for the last year, as part of an aggregate device (combined with an RME UFX) to allow MaxMSP and Gig Performer (a product I helped develop) communicate with each other and to be honest, I barely even remember that Loopback is even there. Perfect example of set and forget If your goal is to work on your music rather than futz with configuration.
Don't get me wrong, it seems like a nice piece of software. As I said, there is just a free, opensource, platform independent alternative. And since this article format here seems to have an educational aim, I find that it would be good to mention jack. Yes, sometimes Jack can be a PITA, but actually if you got used to it, it's very simple.
It's an alternative in the sense that connecting some audio outputs from an interface back into audio inputs of that interface is an alternative.
I don't think it's a good alternative nor do I think it's an equivalent alternative. Unless one's time is worth very little or nothing, "free" is not a good argument. What one will save in money, one will quickly lose in time (often worth way more than the money that might be spent) just figuring out how to use and configure Jack. I think you'll find that most people who have used Loopback will say the same thing.
The only downside is that it is Mac only. But there's Virtual Audio Cable for Windows which is also pretty good.
Hm, you are exaggerating here a bit. You didn't say exactly that, but it sounds like "Jack is an alternative for people whose time is worth nothing". But yeah, I get your point, its a convenient program. Maybe its a great program. I don't want to repeat myself, I think you can see that I was just saying that Jack is also interesting and I found it weird that it was not mentioned. Maybe it came out the wrong way. I think you even need it if you want to play around with FaustLive for example. That's what I meant with "industry standard", although I see that this might be the wrong word. Suum cuique I guess
I'm with DHJDHJDHJDHJ in terms of my own (and admittedly and now limited experience, since I don't use it any more for some of the reasons he described). I've used Jack and Soundflower and Loopback, and I'd say that Loopback's worth the dough in terms of ease of use - it's crazy simple and (so far, anyway) it "Just works." Whether or not it's worth paying your money for isn't something that's my business.
Rogue Amoeba got my money for this one, and I'll second Darwin's comments on it.
