Re: laptop setup: unwanted clicks

[Richard Sales <richard@glasswing.com>]

I second the thought that it's digital clock (not MIDI clock or time code).  Most likely suspect.

Another is, IF you're playing back prerecorded audio and have edits, in the old days I would experience clicks at the beginnings and ends of edits if the edits weren't faded in and out. 

Also, on VERY DRY days clicks occasionally reappear in my setup (ProTools etc).  Static in the air.  But always fading edits in and out kills 'em.

I also had a SampleCell card that clicked when it got too warm!  I had to reboot when it did.

I would write the creator of the internal looper you're using and ask them about the clicking/clocking. 

Clocking issues can be a very infuriating mystery.  But they can be solved!

Good luck.  
richard sales
glassWing farm and studio
vancouver island, b.c.
800.545.6846
250.752.4816
www.glassWing.com
www.richardsales.com
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www.blueberryfieldsfarm.com
On 30-Mar-06, at 8:18 AM, jeff larson wrote:

> > From: nico spahni [mailto:nicosp@gmx.net] 
> >
> > I've been experimenting with a laptop looping setup (Apple 
> > G4/1.25, RAX, Sooperlooper, various plug-ins).
> >
> > Basically everything works pretty fine if it weren't for 
> > those unwanted clicks that make themselves heard every now 
> > and then. I haven't figured out yet when exactly they happen 
> > - not necessarily when I change a setting or hit a button.
> >
> > Does anyone know what I'm talking about? What is the source 
> > of these artifacts?
>
> The most common reason for clicks is that your audio block size (and
> therefore your latency) is too low.  I'm not very familiar with Apple
> audio, but somewhere there should be an option to select a block size,
> typically with numbers like 128, 256, 512, 1024, etc.  Select the next
> higher number and see if the clicks go away.
>
> The issues around block size and latency are complicated.  Basically
> the sound card is constantly asking the audio application for a small
> block of samples to play.  The application has to fill this block in a
> very small amount of time, a few milliseconds.  If this block cannot
> be filled within that time, you "miss an interrupt" and there is a gap
> in the audio stream which sounds like a click.
>
> There are many factors that affect how long it takes an application to
> fill this block but mostly it is the speed of the processor, and the
> number of other plugins or applications you have running at the same
> time.  The more plugins you try to run the slower the application
> becomes and the more likely you are to miss an interrupt.  Some
> plugins are faster than others, delay effects are usually pretty fast
> but complex ones like convolution reverbs are very slow.
>
> If you can't tolerate the higher latency caused by larger block sizes,
> then the only option is to reduce the number of plugins you're
> running.  Of course you have to be careful about non-audio
> applications that are also running.  Don't be surfing the net or
> defragmenting your disk while you run an audio app.  Everything else
> should be shut down.
>
> The second most common reason for clicks is simply software bugs.  If
> it is a software bug, the clicks usually happen regularly, like at the
> start point of the loop, or after a certain function is performed.  If
> the clicks happen at random it is probably due to latency.
>
> Jeff