The client is of my own making. And it doesn’t provide any settings to jackd, as I don’t really see any options in the api to do that. 
But it would of course be much better to setup samplerate, period size, etc from the client. 
If could tell me how to set: "/usr/bin/jackd -p512 -dalsa -r48000 -p64 -n2 -D -Chw:MADIFXtest -Phw:MADIFXtest” this programmatically from the client that would also be of great help!

It still remains a mystery to me how to could magically work on my other system..

cheers,
Fokke


On Aug 2, 2018, at 16:25 , Paul Davis <paul@linuxaudiosystems.com> wrote:



On Thu, Aug 2, 2018 at 10:13 AM, Fokke de Jong <fokkedejong@gmail.com> wrote:
Hi Paul, 

Thanks for your input. That clears one thing up for me.
Since I’m not using qjackctl, only one client that starts jackd, it makes sense that it;’s using default values.
On my previous system it did always seem to use the ‘correct’ settings. So do you have any idea what other place jackd might me getting its settings from? The client is the same..

jackd itself will never save ~/.jackdrc either. That's done only by control clients like qjackctl.

jackd has its own hardcoded defaults if none are available.

What is the client that starts jackd?