[LAU] qjackctl and the hardware latency setting

[Len Ovens]

On Wed, 1 Jan 2014, Maciej (Matchek) Bliziński wrote:

> Hello list,
> 
> I've come across a problem where the hardware latency numbers entered into
> qjackctl setup window don't take effect. I wrote up the details here:
> 
> The workaround was to start jackd from command line and pass the -I and -O
> options that way.

As qjackctl comes from Ubuntu, it tries to control jackdbus and not jackd. 
This can be changed in qjackctl settings, but probably will not help :) 
The real problem is probably (use ps x to check) that jackd is already 
running before you start qjackctl which means qjackctl can not control 
jackd. Why might this happen? Normally it is because you have started an 
application that requires jack and that process has started jack for you 
with whatever it thought was good parameters. The cure is to always start 
qjackctl and use it to start jackdbus before running anything that uses 
jack as soon as you login.

To test this, logout, login, start qjackctl, use it to start jack. You can 
use qjackctl's "Status" window to see what parameters are current.

--
Len Ovens
www.ovenwerks.net