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Audio glitch every 9 seconds - not wifi/bluetooth/disk/tasks

Discussion in 'Recording' started by mrcheeky, Dec 30, 2007.

  1. mrcheeky

    mrcheeky Guest


    I get a recurring glitch in audio every approx 9 seconds (sometimes every 18 secs), either when recording or even just monitoring. I've disabled Wifi (Airport), Bluetooth, disk/cpu monitoring and schduled tasks. I'm only monitoring 1 channel of audio, albeit at the lowest buffer setting (64 samples in Cubase). I know that I can raise the buffer size and the problem dissapears, however it's a shame that I need to do this - everything is completely fine for 9 seconds (cpu/ram/io don't even flinch), however I just get this glitch like clockwork. It's like a double-glitch, both seperated by a few milliseconds.

    Interestingly, when I do exactly the same test with the built-in mic, everthing is fine.

    I just want to know what limit I am reaching - any ideas?

    Cubase LE 4
    MacBook 2.16 GHz Intel Core 2 Duo
    1 GB ram
    Lexicon Omega soundcard via USB2
  2. pr0gr4m

    pr0gr4m Well-Known Member

    The only things I can think of to suggest are:

    -Increase the buffer size
    -Look for updated drivers for the Omega
    -Replace the Omega with a different interface

    Are you recording to the system hard drive? If so, you may want to get a second external drive and record the audio to that. I don't know if it would help with the immediate problem but it takes one potential cause out of the loop.
  3. bwmac

    bwmac Active Member

    yip, get the updated drivers for asio and increase the buffer size if all else fails. Its a balence you have to find.

  4. Space

    Space Well-Known Member

    Probable a demo plug-in beeping.
  5. Randyman...

    Randyman... Well-Known Member

    Try disabling your CD/DVD Drive in the Device Manager. Some of the TSST Corp DVD drives have been known to cause issues like this when they "Poll" the bus...

    You can also try to use this app - it shows you the realtime Kernel DPC Latency of your system.. Disable stuff until the spikes go away:


    PS - Here is a shot of my P5B-E DAW ( :eek: ) :


  6. mrcheeky

    mrcheeky Guest

    thanks guys! I'll try all your suggestions, there's a couple of things you mention which I hadn't thought of.
  7. gdoubleyou

    gdoubleyou Well-Known Member

    Sounds like you are experiencing the cpu spike feature of the Mac version.

    To remedy use bootcamp, and load xp/sp2.

    There are several threads about cpu spikes at cubase.net

  8. Boswell

    Boswell Moderator Distinguished Member

    Re: Audio glitch every 9 seconds - not wifi/bluetooth/disk/t

    USB drivers are polled by a clock interrupt, not event driven. 64 samples is too small a buffer to support USB audio activity - increase it, or switch to FireWire. The built-in mic does not use USB so will not show this problem.

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