Audio Latency Problems


    Jan 18 2008 | 7:23 pm
    Hi everyone, I am having trouble with a patch that is giving me some crazy latency.
    It is a bandpass filter using cascade, (which "kjg" was so kind as to help me with in this thread ... http://www.cycling74.com/forums/index.php?t=msg&th=30396&start=0&rid=5838&S=cb25f54275459f1ca01126a38d740d42 )
    The filter is pretty much exactly as given to me by "kjg", and it is encapsulated and the display is in its own window in a bpatcher
    I tried kjg's patch (which seems perfectly well written) by itself and I'm still getting the delay...
    at first it's not bad, it's just about right on
    about a minute later there's a little delay, noticable but still I can still live with it
    at about 1 more minute later it's like a 50ms delay
    about 15 minutes later it's about a 400-500ms delay.
    and I've tried all different I/O and Signal vector sizes
    if they are too small, it starts off better, but then still continues to delay over time, and it distorts a little after a few minutes as well.
    if it's too large, then it starts a little more delayed and gets worse...
    my CPU utilization never goes above 15%
    I'm on an iMac G5 OSX 10.4.10 1.8GHz PowerPC 1GB DDR SDRAM
    and nothing else is running on my computer, including any widgets
    any suggestions???
    thanks :)
    Michael

    • Jan 18 2008 | 9:16 pm
      bizarre, the only thing I could say is to try with Overdrive on and off and see if there's a difference, but I don't know if this matters in this case (unless maybe the "latency" is event-driven, as it might be...).
      Don't know enough about the low-level audio-card stuff, but I wonder if the problem is below Max and in the card? or how Max talks to this particular one?
      There should be some other good answers to this one. --CJ
    • Jan 18 2008 | 9:16 pm
      Michael schrieb:
      > about 15 minutes later it's about a 400-500ms delay.
      half a second delay building up sounds weird. I remember the patch and
      even started to play with it, but that wouldn't create accumulating delays.
      Just post your version of the patch again, I am sure there is an
      explanation...
      Stefan
      --
      Stefan Tiedje------------x-------
      --_____-----------|--------------
      --(_|_ ----|-----|-----()-------
      -- _|_)----|-----()--------------
      ----------()--------www.ccmix.com
    • Jan 19 2008 | 12:24 am
      I should have mentioned this at first, but I also experienced similar problems a while ago when using a simple patch I wrote with fiddle~ converting frequencies to MIDI.
      It is fine every time I turn the audio engine off and on again, but then the same problem happens again.
      My audio interface is USB (the Event EZBus). And I've never had any problems with it anywhere else.
      I'll post the patch when I get home, and I'll try it with Overdrive On and Off and see if there's a difference.
      thanks for the help so far
      Michael Sperone
    • Jan 19 2008 | 11:26 am
      Michael schrieb:
      > I should have mentioned this at first, but I also experienced similar
      > problems a while ago when using a simple patch I wrote with fiddle~
      > converting frequencies to MIDI.
      It seems to be a bug in the world simulator (matrix~) we are all living
      in...
      In other words, if latency is accumulating, there must be a memory for
      that delay. If its not in Max, its in the matrix... ;-)
      Stefan
      --
      Stefan Tiedje------------x-------
      --_____-----------|--------------
      --(_|_ ----|-----|-----()-------
      -- _|_)----|-----()--------------
      ----------()--------www.ccmix.com
    • Jan 21 2008 | 5:54 pm
      Hi,
      I tried turning overdrive off (it was on before) but that didn't help anything
      here is the cascade patch that I'm using...
      any more ideas? because I don't know what else to do :(
      -Michael
    • Jan 22 2008 | 2:40 am
      I've had this exact problem.
      For me, I could fix the problem by using different sound cards.
      The weird thing is, I had no problem with the built in sound card (on a G4 powerbook). Hope this helps.
      David
    • Jan 24 2008 | 11:16 pm
      YES!!!! It works!!!!
      davydka, you are a genious! I am using the built-in sound and it works GREAT!!!
      Thanks everybody for your help with this!
      -Michael