Being the OP (I think) I didn't mean to stir controversy with my questions. As has been pointed out there are different ways to get to your preferred configuration. Be that qjackctl, your own home brew, or some combination of things. Personally, most of the time, I just want it to work so I can get about MY business and not the business of becoming a guru on some part of the chain I need to get MY business done. (My OP came from a desire to figure out why a particular configuration seemed to be so finicky. A particular laptop, the alsa interface, and USB in/out ports presented by a Behringer X32, plugging the same usb cable into another laptop, just worked every time. In order to troubleshoot, I thought maybe I'd gain more insight by mimicking what qjackctl does from the command line. But, when I tried to duplicate a qjackctl start from the command line, was stymied as to how.) The entire linux audio (generic and pro) and the evolution thereof makes it very difficult to get a clear picture of how it all works and how to get what you want. (I've been a hardware/software engineer for 40 years, messing with jack for the last 10 and still have questions...) To a new comer or someone coming from a different audio platform, it would be hard not to wonder if linux audiophiles aren't trying to make appear you need to be some sort of linux mage to make it work. When in fact, you just need to be a persistent investigator due to it's evolution (and lack of cohesive end user documentation, again, because of it's evolution). Oh, and some background in software, hardware, signal processing, and system configuration doesn't hurt... For those who just want to make music or record something quick...better stick to other platforms and cough up the money that requires. For me the corner case argument is moot. There a myriad of use cases and work flows. In my case, I, mostly, do theater work where playing prerecorded tracks, controlling various devices (mixers, projectors, sound fx, players, etc.), and following a script is typical. For sound, that typically, means using player apps that may or may not be jack aware (though, when the choice is mine, I just use LinuxShowPlayer, since it knows JACK), so having the pulse ports just appear when jack is started (by whatever means) is nice. And, while I RARELY use Skype, being able to play youtube without having to mess around is handy. Yes, I know I could get it all to play nice with just jack...but, that's not what I prefer to use my time doing. And, for full disclosure, I use JACK to get to MIDI in ShowControl, the open source theater production control software we are developing. But, I don't have any desire to know more about the internals of jack than I need to to use it as a tool. (but I need to figure out how to get that to start with the preferred sound configuration...so I'll be looking in detail at things like Christopher's jack-select, alas, deeper into the rabbit hole.) ;) It's all good...just complicated. :) Regards, Mac On Tue, Mar 14, 2017 at 1:28 AM, Ralf Mardorf <ralf.mardorf(a)alice-dsl.net> wrote: