Crackling when auditionning if plugin in monitor channel introduces latency

[dtb]

I have insert plugins in the montior bus channel. No problems with playback and crackling.
But when I try to prelisten/audition a file in the import dialog or use the play function in the analysis windows after exporting ... I get crackling.
I noticed that this is only the case if a plugin introduces latency.

I did the following tests:

1.
- fabfilter pro q3 (vst2-version) set to zero latency -> no problem
- fabfilter pro q3 (vst2-version) set to Natural phase (320 spl latency) -> crackling
- fabfilter pro q3 (vst2-version) set to Linear phase (116,1 ms) - heavy crackling

2.
sonarworks reference - disabled - > no problem
sonarworks reference (latency) - enabled - > heavy crackling

3.
dearVR - disabled - > no problem
dearVR (46,4 ms latency) - enabled - > heavy crackling

Can anybody confirm this?
Tom

Windows 10 Pro
RME Fireface UFX+
Mixbus 32c 6.2.x (latest version)

[madmaxmiller]

I have insert plugins in the montior bus channel. No problems with playback and crackling.
But when I try to prelisten/audition a file in the import dialog or use the play function in the analysis windows after exporting ... I get crackling.
I noticed that this is only the case if a plugin introduces latency.

I did the following tests:

1.
- fabfilter pro q3 (vst2-version) set to zero latency -> no problem
- fabfilter pro q3 (vst2-version) set to Natural phase (320 spl latency) -> crackling
- fabfilter pro q3 (vst2-version) set to Linear phase (116,1 ms) - heavy crackling

2.
sonarworks reference - disabled - > no problem
sonarworks reference (latency) - enabled - > heavy crackling

3.
dearVR - disabled - > no problem
dearVR (46,4 ms latency) - enabled - > heavy crackling

Can anybody confirm this?
Tom

Windows 10 Pro
RME Fireface UFX+
Mixbus 32c 6.2.x (latest version)

Buffersize?
MMM

[dtb]

Buffersize 2048 samples, out of curiosity I tried 128 or 256 samples ... Buffersize makes no difference ...
I only get problems when auditioning ...

Tried to route audition out to another hardware output failed. A hint is shown after I/O latency (ambiguous) in the main bar in the mixbus window.
Log says:
[WARNING]: Ambiguous latency for port 'auditioner/audio_out 1'
[WARNING]: Ambiguous latency for port 'auditioner/audio_out 2'
Seems as if the audition feature is somehow "hard-wired" to the monitor section.
The issue with crackling only occurs when I use a plugin in the monitor signal chain (processors) that introduces latency.
I will write to harrison support and a link to this thread.

[madmaxmiller]

Buffersize 2048 samples, out of curiosity I tried 128 or 256 samples ... Buffersize makes no difference ... 
I only get problems when auditioning ...

Tried to route audition out to another hardware output failed. A hint is shown after I/O latency (ambiguous) in the main bar in the mixbus window.
Log says:
[WARNING]: Ambiguous latency for port 'auditioner/audio_out 1'
[WARNING]: Ambiguous latency for port 'auditioner/audio_out 2'
Seems as if the audition feature is somehow "hard-wired" to the monitor section.
The issue with crackling only occurs when I use a plugin in the monitor signal chain (processors) that introduces latency.
I will write to harrison support and a link to this thread.

<following>

[Ben@Harrison]

I would not expect "crackling" in this case, but the report "Ambiguous latency" is likely a clue to the problem. The most common cause for this problem is when you "split" a track/bus's direct output (in this case the auditioner) and feed one output directly to a soundcard, while the other output goes through the mixer (which will have a different latency-correction path). In that specific setup, Mixbus only has one delay buffer on the "direct output" of a channel. (that is not true for aux-sends and other internal feeds...you can have lots of those and still be latency-compensated)

When you are using the Monitor section, there is an implicit connection from the Auditioner into the Monitor section and you shouldn't make a parallel connection to the soundcard outputs. Try disabling all connections from the Auditioner and see if that solves the issue ... ?

-Ben

[dtb]

@Ben thx for chiming in. Ok, implicit connection from the Auditioner into the Monitor section ... That's what I wanted to know. I just tried to establish a connection from the Auditioner AFTER I noticed the issue with crackling. So atm no connections any more from the Auditioner ecxept the the implicit connection you mentioned.
In the meantime Nik from Harrison support could reproduce the issue :-( and forwarded it to the rest of the dev team for review (he used XT-LC for testing).
I will report any results and further info in the thread.

[Ben@Harrison]

Excellent. Usually, when we can recreate it here, we can fix it.

Best,
-Ben