[PlanetCCRMA] xruns

Jan Depner eviltwin69@cableone.net
Sun Nov 5 11:57:02 2006

On Sat, 2006-11-04 at 20:21 +0200, DA Forsyth wrote:
> On 3 Nov 2006 at 7:21, Jan Depner wrote masterfully:
> Hi Jan
> > > This glitching is really worrying me, since I think it will get
> > > worse if I insert Jamin for the mastering.   problem....!
> > 
> >     I'm assuming that you've made the mistake of setting your
> > frames/period to something way low like 64 or 128.  
> it was.   but please explain more on this topic.  are you saying that 
> for recording, that low setting is correct, but for playback it 
> should be higher?  what about when overdubbing and one needs low 
> latency while playing back tracks and recording new tracks at the 
> same time?

    That would depend.  If you don't have hardware monitoring then
you'll need to set the frames/period low so that you can software
monitor and record at the same time with some semblance of simultaneity.
Otherwise you'll hear the played tracks, you'll play your guitar (or
whatever), and then you'll hear your guitar/whatever at some later time.
It's very confusing.  If you've got hardware monitoring this is not an
issue so you want to set your frames/period to as high a level as
possible.  I've heard that some people like to have effects on their
vocals when they record.  If this is the case you'd either need to use
an outboard effects unit and hardware monitoring or set the
frames/period very low, use inboard effects, and software monitor.

> > For mixdown and/or
> > mastering you should set it to as high a value as possible.  If you
> > have hardware monitoring (like with most of the ice1712 chipsets -
> > M-Audio Delta 1010 for example) you should always set it to as high a
> > value as possible.  I use 2048.  This should get rid of your xrun
> > problem.
> I have a Delta 1010LT.   I set it to 2048 (tried 4096 but jack would 
> not start) and still got glitches, though fewer.   I've got a gverb 
> plugin on 2 channels, both bypassed, enabling them doesn't make much 
> difference, except during a parameter drag it will usually glitch.

    Yeah, the ice1712 doesn't like 4096 - I have the same thing with my
DSP2000 C-Port.  If you've got it set to 2048 and you're still getting
xruns you've got some other problem.  With the system you described you
shouldn't really be having any problems.  You might want to make sure
your sound card interrupt is not being shared with another device -
especially not a busy device.

Jan 'Evil Twin' Depner

"Life should NOT be a journey to the grave with the intention of 
arriving safely in an attractive and well preserved body, but rather to 
skid in sideways, chardonnay in one hand, chocolate in the other, body 
thoroughly used up, totally worn out, and screaming 'WOO HOO, what a ride'"