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IDProjectCategoryView StatusLast Update
0008365ardourbugspublic2020-11-21 20:10
Reporterunfa Assigned To 
Status newResolutionopen 
PlatformArchOSLinuxOS Version(any)
Product Version6.2 
Summary0008365: Randomly introduced latency
DescriptionI'm using Ardour 6.2.43 (rev 6.2-43-g15fcb5c782) - I've recently noticed random latency problems on certain tracks. Suddenly my drums or bass synth would start lagging behind the click track by 0000071:0000060 ms.
At first I thought it's a problem with some plug-ins I'm using, I suspected LSP, as I've used them a lot in the affected project.

But then it happened after I added submix bus to a Black Pearl Drumkit (Multi).
The MIDI track was fed into multiple audio buses. These also send signal to 2 Reverb Buses in varying amounts.
When I've created another bus and routed all the individual channel buses to it - the whole drum line started to noticeably lag behind the rest of the track (quite a surreal sound).

Because of that I started suspecting that the problem might be caused by Ardour itself. Also - I'm not really using any plug-ins that I haven't been using in previously and I've never had such random latency introduced.

If I manually set the latency of my instrument plug-ins - it lets me compensate for it, but then the unexpected latency randomly goes away and my tracks start to rush instead of lagging.

After reloading the session - the latency problems seem to be gone, but re-appear randomly at times.

Here's a video I've quickly made to demonstrate the problem:

Can anyone reproduce this?


related to 0008472 closedx42 Newly added audio tracks are not correctly compensated for latency until Ardour session is reloaded 



2020-10-27 08:30

reporter   ~0025163

Does it still happen when using jack or ALSA


2020-10-28 16:50

administrator   ~0025178

Preferences > Appearance > Toolbar > Display Latency Compensation Info

Does the I/O Latency show "ambiguous latency"?


2020-10-28 17:43

reporter   ~0025180

I'm gonna check when I encounter this again.


2020-11-06 08:17

reporter   ~0025202

I have this problem all the time now. And from what I have observed it applies to all newly added tracks and buses. And the only solution is to reload the project. And doing it every time I add new track is very anoying.


2020-11-06 09:59

administrator   ~0025203

@janisl This sounds like an issue with JACK2. Does using Ardour/ALSA (no JACK) help? Is this with Ardout 6.3.0 ?


2020-11-06 12:31

reporter   ~0025205

@x42 Yes, with ALSA it works fine. It's 6.3.0.


2020-11-09 17:14

administrator   ~0025210

> After reloading the session - the latency problems seem to be gone, but re-appear randomly at times.

Could it be that you have changed jack's buffersize while Ardour is running? and from then on there were inconsistencies (existing tracks newly created ones)?


2020-11-11 14:53

reporter   ~0025214

I don't change buffer size, and I can reproduce this every time.

Issue History

Date Modified Username Field Change
2020-08-17 19:23 unfa New Issue
2020-08-17 19:23 unfa Tag Attached: latency
2020-10-27 08:30 soundguy30 Note Added: 0025163
2020-10-28 16:50 x42 Note Added: 0025178
2020-10-28 17:43 unfa Note Added: 0025180
2020-11-06 08:17 janisl Note Added: 0025202
2020-11-06 09:59 x42 Note Added: 0025203
2020-11-06 12:31 janisl Note Added: 0025205
2020-11-09 17:14 x42 Note Added: 0025210
2020-11-11 14:53 janisl Note Added: 0025214
2020-11-21 20:10 x42 Relationship added related to 0008472