Playback Problem

When I playback the recorded content I hear disturbances similar to playing live audio when you have an unclean volume knob. There is no clipping and it does not matter which playback program I use. Any ideas what could be causing this?
Thank you.

Sounds to me like an xrun issue.


Thanks for the information.
I will dig further into this problem. However just to add to my initial post. I am using Presonus FP10 and jack uses libffado. The crackling sound also appears when I am recording a single track and it also appeared yesterday when I had both Rosegarden recording midi and Ardour recording 2 audio tracks simultaneously. Needless to mention that I have just been experimenting with Linux recording since last 5 days so I am fairly inexperienced. Furthermore, it is not a hardware problem as everything records well under Windows.

Thank you.

What Linux distro are you using?

fedora 12.

you need to supply a LOT more information, as detailed here: … JACK settings in particular are critical information.

Thank you for the response. I am not sure if its a bug in Ardour and so I will just respond via email:


  1. CPU = AMD Athlon II X4 620

  2. RAM = 3091252 Kb.

  3. DISK SPEED = 7400 rpm

  4. FREE SPACE = 7.5Gb

  5. system = Fedora 12

  6. Kernel =

  7. Ardour = 2.8.11 (build from version 7387)

  8. JACK = 0.118.0

  9. /etc/settings/limits.conf has
    @audio - rtprio 99
    @audio - nice -10
    @audio - memlock 2318436
    audio hard memlock 512

    Realtime - Priority = 89 - No Memlock - Frames/Period = 16 - Sample Rate = 44100 - Periods/Buffer = 256
    Enable ALSA Sequencer Support
    Enable Dbus Interface.

I can provide more if required. Note Ardour would occasionally freeze w/o realtime mode. Also yesterday I heard some clicking in Rosegarden recording as well - however it was considerable less frequent than Ardour.