Delay Compensation Problem?

[JKR]

Hi
I run PT2021 on iMac with Apogee Ensemble TB which has DSub to various hardware & 500 series rack.

I’m having sync problems when I change HW buffer setting.

Example. Slate SSD5.5 drums has hardware on the track I/o insert as well as other plugs. I also have manually recorded the kick & snare via hardware which are bang on the grid. At a buffer of 256 everything is locked in with the track as expected. However when I change the buffer to 512 the midi & audio drums go out of sync. I have a similar problem with the LV which also has hardware on its i/o insert.

I spent a good amount of time setting up the hardware offset.
Delay compensation is active.

Any ideas how I can prevent sync running out with different buffer settings?

Thanks!

[s.d. finley]

Originally Posted by JKR

Hi
I run PT2021 on iMac with Apogee Ensemble TB which has DSub to various hardware & 500 series rack.

I’m having sync problems when I change HW buffer setting.

Example. Slate SSD5.5 drums has hardware on the track I/o insert as well as other plugs. I also have manually recorded the kick & snare via hardware which are bang on the grid. At a buffer of 256 everything is locked in with the track as expected. However when I change the buffer to 512 the midi & audio drums go out of sync. I have a similar problem with the LV which also has hardware on its i/o insert.

I spent a good amount of time setting up the hardware offset.
Delay compensation is active.

Any ideas how I can prevent sync running out with different buffer settings?

Thanks!

I think you will have to ping the latency at different buffer sizes and apply as needed. The Auto delay compensation only works with Avid hardware, or 3rd party hardware that tricks PT into thinking it is Avid HW, ie Lynx and a couple others.
Of course I might be wrong about this......

[midwinter]

I'm experiencing this also, only just noticed on 2021.6. Hadn't noticed it as an issue before now. I don't think this relates to ADC however, because that it for plugins only, correct? My issue sounds identical to the OP. Tracking at different buffer settings will result in different alignments to the grid. Eg, trying to track guitars to existing drums that are locked to the grid, will result in different sync results depending on which buffer setting is used. PT appears to pull the clip backwards after recording. This is occurring in slip mode... curious now if this has been happening for longer than I was aware?

OS Name Microsoft Windows 10 Pro
Version 10.0.19042 Build 19042
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OS Manufacturer Microsoft Corporation
System Manufacturer Supermicro
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Audio Interface: Presonus Studio 192

[albee1952]

2 things come to mind:
1-It may be that you need a different offset for each buffer setting because changing the buffer also changes the timing of anything that goes out(thru hardware) and back in
2-what specific hardware is in play? All to often, a plugin will match or beat the hardware and eliminate the hassle

[JKR]

Thanks guys.

I run out through some RND preamps and comps and into various 500 series mudules, api, Camden.

Makes sense to input different offsets for each buffer but also a pita. I insert i/o while working the song, not just at mix, so reducing buffer for an overdub is common, but it would be way better for workflow if I didn’t have to tweak the I/o too….

[JKR]

Even weirder today.

Decided to re-test and adjust my HW offsets.
I followed the recommended method.
Have audio on track 1 and add hardware as an insert.
Bus the output of the track to a new audio track 2.
Measure the time difference between the audio on tracks 1 & 2 to determine the offset values.

Any offset value actually pushed the audio on track 2 earlier on the grid than track 1!

Leaving offsets set at zero gave me the closest alignment. Totally weird and different to when I originally set up all my HW inserts. Tried on a blank session and on a session with lots of audio and midi - same result. Buffer changes have less affect.

My Apogee specs show a 1.1m/s round trip but my audio has decided it’s zero, well at least it has for today…..

[albee1952]

Hmmm, I avoid all the hassle by using the hardware during tracking only

[s.d. finley]

Originally Posted by JKR

Even weirder today.

Decided to re-test and adjust my HW offsets.
I followed the recommended method.
Have audio on track 1 and add hardware as an insert.
Bus the output of the track to a new audio track 2.
Measure the time difference between the audio on tracks 1 & 2 to determine the offset values.

Any offset value actually pushed the audio on track 2 earlier on the grid than track 1!

Leaving offsets set at zero gave me the closest alignment. Totally weird and different to when I originally set up all my HW inserts. Tried on a blank session and on a session with lots of audio and midi - same result. Buffer changes have less affect.

My Apogee specs show a 1.1m/s round trip but my audio has decided it’s zero, well at least it has for today…..

Are you testing with Delay Compensation turned on? Try testing with it off

[JFreak]

Originally Posted by albee1952

Hmmm, I avoid all the hassle by using the hardware during tracking only

Yes, you cannot defy laws of physics. If you do extra ADDA roundtrip during tracking you will add latency no matter what. Save that processing for mixing. If you want to use analog gear while tracking do so before AD conversion.

[FloydPepper]

Originally Posted by JKR

Even weirder today.

Decided to re-test and adjust my HW offsets.
I followed the recommended method.
Have audio on track 1 and add hardware as an insert.
Bus the output of the track to a new audio track 2.
Measure the time difference between the audio on tracks 1 & 2 to determine the offset values.

Any offset value actually pushed the audio on track 2 earlier on the grid than track 1!

Leaving offsets set at zero gave me the closest alignment. Totally weird and different to when I originally set up all my HW inserts. Tried on a blank session and on a session with lots of audio and midi - same result. Buffer changes have less affect.

My Apogee specs show a 1.1m/s round trip but my audio has decided it’s zero, well at least it has for today…..

I have the same problem and posted a new thread.

https://duc.avid.com/showthread.php?t=416731

Could not get it to work so far. Audio gets invariably pushed earlier by a few samples.