LinuxQuestions.org - How to start JACK with KDE 4? (and which JACK should I use?)

Hi again :)

I'm using KDE 4 on Arch Linux, and I've just installed JACK again, and since I can't find any decent documentation on this, I'm having a bit of a problem.
Currently I have jack from [extra] installed, rather than jack2. When I try starting jack as the ArchWiki suggests, i.e. by typing "jackd -d alsa", I get the following error:

Code:

$ jackd -d alsa

jackd 0.120.1

Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben Hohn and others.

jackd comes with ABSOLUTELY NO WARRANTY

This is free software, and you are welcome to redistribute it

under certain conditions; see the file COPYING for details



could not open driver .so '/usr/lib/jack/jack_firewire.so': libffado.so.2: cannot open shared object file: No such file or directory



JACK compiled with System V SHM support.

loading driver ..

creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit

control device hw:0                                                                                                                                              

the playback device "hw:0" is already in use. Please stop the application using it and run JACK again                                                            

cannot load driver module alsa

I've also tried jack2 from [community], and after starting it with "jack_control start", I get this...

Code:

$ jack_control start

--- start

DBus exception: org.jackaudio.Error.Generic: Failed to start server

So how do I start it? I'm guessing jack doesn't want to start because some other KDE application grabbed alsa before jackd (but I've been wrong before), and I don't have the slightest idea what jack2 is about with that "generic" error. If anyone would help me shed some light on this, I'd appreciate it a lot.

Thanks in advance! :)