Playback distorted

morgon · May 25, 2024, 10:17pm

Hi,

as a total ardour-noob I am just trying to check if my setup is ok and I am already failing with the most basic task imaginable: Importing a wav-file and playing it back.

I am on Debian testing with ardour 8.1.0 and for the sake of this exercise I have shutdown pipewire and use ardour with alsa.

So I create a new session and import a wav-file which shows up as a new track, waveforms are displayed, everything looks fine, but when I now try to play it back I get extremely distorted sound (it is recognizable though) and the speed of the playback also is too slow…

Could someone please enlighten me what may be going wrong here?

ccaudle · May 26, 2024, 2:34pm

Is the session sample rate the same as the wav file sample rate?

morgon · May 26, 2024, 2:40pm

Yes the rates are the same, but I have found that the problem seems to be caused by the soundcard.

When I use the integrated sound card of my mainboard or an usb-soundcard everything works fine, but when I use the hdmi-output of my nvidia card I get this problem…

seablade · May 26, 2024, 5:15pm

It is quite likely that the HDMI output only supports 48k even if it seems to report working at other sample rates.

Seablade

slash · May 26, 2024, 6:01pm

Also try to raise the Jack buffer size by an order of magnitude (which is the solution for my KDE Slimbook, with Ryzen/AMD graphics rather than nvidia).
To begin with, aim for a delay of at least 100ms, and then try raising or lowering it, until “it works”…

morgon · May 26, 2024, 10:04pm

I have made some further experiments and it seems to depend on the configured buffer-size for the nvidia-card.

eg if I choose 1024 samples I get this distortions, if I choose 4048 samples everything works fine.

Can someone explain what exactly is going on here?

x42 · May 26, 2024, 10:49pm

HDMI requires a min. buffesize of 4096 samples/cycle (and 48kHz sample-rate).