16 Oct
2004
16 Oct
'04
9:15 p.m.
Now I'm
""working"" with a Creative Audigy card and I want to buy a new
one basically because Audigy doesn't allow realtime monitoring through
jack (the latency is at least 45ms and for me is too much) and because
I want to have a good dynamic response to record my acoustic guitar
(now it saturates the input or I must record at a low volume with a lot
of noise).
Very strange that you cannot achieve better performance... I don't know
the audigy, but with a crappy sb128 on athlon 800 w 256Mb ram I can get
with "reasonably few" xruns to 23 ms and even to 11 (i speak of the
values reported by qjackctl) - I suspect that your problem comes from not
having an external mixer for conveniently routing of inputs and outputs
and for monitoring what you are playing.
Could also be a problem of a not enough powerful pc?
Also I though that I shouldn't allow any
"xrun" and I disabled "Soft
Mode". Now I see I "must" allow "xruns" but what criteria do I
follow?
how much "xruns" can be allowed?
It's not really how much xruns, it's more where they occur. Right in the
middle of an important take is bad. If they only happen when you're messing
about onscreen then you just have to discipline yourself to keep your hands
off the mouse. Really you don't want any [ha!], but having Jack exit every
single time you hit an xrun can be equally annoying.
And finally, to
tweak jack configuration, I ignore if it can be useful
to change other parameters.
Now I only play with "periods" and "frames", and I don't know the
exact
influence of the parameters: "Start Delay"(why jack has an initial
delay?) and "Timeout"(of what? it sounds the same than latency...). I
didn't found docs about jack about these issues... Does anybody know?
Should I try the jackit user list or it is too technical?
I have a start delay of 2 secs and a timeout of 500ms. The former gives Jack
longer to start up - I assume it allows the prefilling of buffers or somesuch
[?]. The latter means it waits longer before giving up. AFIU
If there
isn't documents on these questions, when I'll finish, I'll try
to write it down and make a "beginner's" doc.
Also I think that it should be a place where the people could post their
experiences in different sound cards in linux and their jack
configurations under different environments. This should make our life
easier...
I assume you're familiar with:
http://www.agnula.org/download/demudi/1.2.0-FAQ
http://wiki.agnula.org/ is a good place to start work on additional
information that is needed. It would be brilliant if more people used it ;)
cheers
tim hall
thanx!