[LAU] why shouldn't clients autoconnect to jack

Mark Knecht markknecht at gmail.com
Mon Mar 23 13:09:08 EDT 2009

On Mon, Mar 23, 2009 at 3:50 AM, Atte André Jensen
<atte.jensen at gmail.com> wrote:
> Hi
> I often heard that it's considered bad when clients automatically auto
> connect it's outputs to jack. I agree, mostly since:
> 1) This makes routing through other software before output difficult
> 2) The patchbay in qjackctl makes it easy to make auto connects anyways
> But could anyone point me to some explanation from the devs (Paul Davis
> for instance) of why this is considered bad?
> --
> Atte

Hi Atte,
   Not sure I have much new to offer in the area of why or why not as
others have given the reasons that are most important to me:

1) My main setup has two cards:
Card 0: an onboard chip I use for system sounds and audio where I
don't care too much about quality - MythTV, audio preview in gnome
when I hold my mouse over the icon, etc.
Card 1: my main HDSP9652 card where I do care very much about sound quality

Which card would the system automatically connect to? I suspect
autoconnect would grab the first card which is wrong in my case for
most Jack apps.

2) The HDSP9652 has 3 ADAT ports and a spdif port. I have two sets of
monitors and two different D/A's. In my case I use the ports 23/24 for
one set of speakers with a lower end D/A, and I use ports 25/26 (the
spdif outputs) with a higher end D/A and a different set of studio
monitors. Autoconnect cannot know which set of monitors I want to use
therefore it can only choose some sort of default and leave me to
fixing things up later anyway.

   All that said, I'm not actually against autoconnect but in fact
prefer it IF it works in a way that makes my life easier. I raised
this issue in a different way 3-4 years ago and my reasoning never
gained traction with anyone. It's my opinion that there should be some
sort of global standard for stuff like this and that apps that follow
the standard should be allowed to use some sort of extra designation
about their Jack system compatibility. Whether an app supports
autoconnect or not, when it does I need to know how to use it and my
experience is that every app does it differently. As a user this
causes me to have to learn each apps way which just makes like harder.
Better if there was a standard tab in the configuration area of each
app with a specific set of common config options so that I can bring a
new app up and not spend time reading the manuals and just make music.

   Note that in my case with the HDSP9652 I have 26 software outputs
so I always do things like Zyn->5/6, Ardour->7/8, Rosegarden->9/10,
Hydrogen->11/12, etc., and then route and mix these in the HDSP's
mixer. There isn't anyway in the world autoconnect is going to handle
that completely automatically.

   I'm not that supportive of the 'first time run' concepts as the
first time I run an app I don't know what it does or how I'm going to
hook it up in the long run. Fine with me if it autoconnects to
something but I still need a simple and standard way to reconfigure
that going forward.


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