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Latency printing mixes back into PT via auxes
Old 12th September 2018
  #1
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Uli Auer's Avatar
 

Latency printing mixes back into PT via auxes

Hey guys,

I've got a question. Does anybody know something more deep about the following issue?:

Running a hybrid mix setup with some hardware inserts on several tracks and busses, passing D/A to an analog summing stage and printing back into Pro Tools I'm facing the situation that

a) re-recording the mix directly via physical inputs to an audio track results in having the I/O setup options "compensate for in(out)put delays after recording pass" being applied -> recorded region / file is in sync to the original tracks.

b) once any Aux channel is put in between the physical input and the re-recording audio track (for example for some final master chain plugins) this does not work anymore - resulting in the audio in the recorded region/file being delayed by a certain (pretty large) amount of time - in my case it was about 157ms.

This does NOT have anything to do with plugin latency at all - even with no plugin inserted the delay is exactly the same....for further testing I shrinked the setup down from my complex template to the most simple track layout:

1) 1 source audio track "A" with a click going D/A through the summing mixer and back A/D

2) 1 audio track "B" recording directly from Avid I/O input

3) 1 aux channel with same input from Avid I/O -> routed to a "bus 1"

4) 1 audio track "C" getting its input from "bus 1"...

No plugins at all - same result after re-recording:

- Track "B" 's audio file is automatically time-aligned with the related options in the I/O setup being active and hence in sync to the source audio on "A".
- Track "C" is late.....

Anybody knows for sure whether this is a general Pro Tools limitation / incapability...? Or even better - whether there's a fix for that issue in order to avoid recording every print file a little longer, cutting the silence on the start of the file by the occured delay and shifting audio around by hand after each printing pass in order to have a printed mix in sync to a rough mix for example...?

Best,

Uli

----------

Mac Pro 5,1 12-core 3,46 GHz 64GB
Avid Pro Tools 2018.7
HD native PCIe card with 4x HD I/O 16x16
UAD-2 Quad & Octo
SSL Sigma / Heritage MCM-8 Summing
Some fine outboard processors
Old 14th September 2018
  #2
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what is your HW buffer size, and what version PT ?
Old 17th September 2018
  #3
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Uli Auer's Avatar
 

Quote:
Originally Posted by DannyMac View Post
what is your HW buffer size, and what version PT ?
Pro Tools 2018.7 - Buffer Size is max 1024 @ 44.1 due to full template....

And another question thinking of your question....:

What should the HW buffer have to do with ITB bussing....?
Old 17th September 2018
  #4
Lives for gear
Sounds like the aux track defeats the i/o offset feature. How about just record the audio and then commit the effects you were using the aux for?
Old 19th September 2018
  #5
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Quote:
Originally Posted by Philter View Post
Sounds like the aux track defeats the i/o offset feature. How about just record the audio and then commit the effects you were using the aux for?
Hey Phil,
thanks for chiming in. Yes, that's exactly what I'm experiencing here....of course it would be a way to go first printing without effects and do the other stuff later....but
a) it would be (or IS) making two steps instead of one (taking more time) and

b) I'm not only talking about this mix print only but also about some bus stems I want to print at the same time .....which also suffer from being misaligned.....

EDIT: To explain that a little better: My analogue mix chain is also constisting of two more busses leaving and again entering Pro Tools in parallel (one stereo bus that contains very dynamic material like fat hits and one SUB bass bus, both not going thru the mix chain in order to not making the gain reduction of the mix chain going crazy). These also go to stem re-recording tracks via auxes....
Old 19th September 2018
  #6
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Few things,

You can manually type in compensation numbers for delay to fix (if it is a static number) in the mixer window.
There was a limitation on bussing one type of channel into another type for delay compensation as written in the Pro Tools notes given with the releases. Change your Aux to an Audio track (solo defeat, blue mode) and see what happens.
Old 19th September 2018
  #7
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Uli Auer's Avatar
 

Quote:
Originally Posted by pentagon View Post
Few things,

You can manually type in compensation numbers for delay to fix (if it is a static number) in the mixer window.

Yes, tried experimenting with disabling ADC on the AUx and typing in values but you can't enter negative numbers - which would be necessary in this case as the task would be to make the signal going thru the aux to the audio track being EARLIER, not later....

There was a limitation on bussing one type of channel into another type for delay compensation as written in the Pro Tools notes given with the releases.

Yes, I've heard about that before, but in this case it's only ONE generation of Aux bussing, not two or more....

Change your Aux to an Audio track (solo defeat, blue mode) and see what happens.

I see what you mean, but that won't help any further because that's exactly the problem here - recording directly to an audio track works because here the "offline" compensation of the delays after the recording pass option in the I/O setup makes its job.....which is exactly NOT the case once I have an aux bus being out in between.....
See what I mean ?
Old 20th September 2018
  #8
Lives for gear
On my I/O screen I have a tab called "I/O Insert Delays" (ProTools 12 HD). I poked around in ProTools and I don't even see this option you mentioned: "compensate for in(out)put delays after recording pass". Have you set up the "I/O Insert Delays" panel? When I think about it, you actually don't seem to want the option you have selected- you want the input delay compensated for at the source, during playback, not applied after the pass.
Old 21st September 2018
  #9
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@ phil :
No, these two things have nothing to do with each other. The settings in the hardware inserts tab are only compensating for delays beyond those that are compensated anyway by the ADC and that are occuring during the insert loop outside the box - for example old digital reverb or delay units have a certain processing latency going on - or maybe vintage digital synths or drum machines....

But first and foremost these settings are applied to hardware inserts only (hence the name)
...means in Pro Tools: having an Out->In loop that has to be the same number of I/O channels going DAAD via the same numerical inputs and outputs on the interface...

But in my situation I'm going out with multiple outputs and coming back into PT with the analog summed mix thru a single stereo pair of inputs - so the hardware inserts tab has no effect here.

The issue I'm facing here is that it seems to be so that PT can't apply this compensating nudge-back process after recording once the signal source for the mix print track is not a physical input but a bus coming from this input....

But the strange thing is that even Avid Support doesn't seem to be able to reproduce this issue (still in the middle of a conversation with them) on their side....

So my initial question was whether anybody could confirm this issue as

a) happening in general and

b) being common knowledge or a known-for-sure PT limitation....

And just fyi: The "compensate" options I was talking about are little checkboxes sitting seperately in the "Input" and "Output" tabs in the I/O setup....
Old 27th September 2018
  #10
Gear Maniac
Sorry, I haven't read the entire thread, but do you have the record track in "Blue Mode"? On Mac, Ctrl-Cmd click the "cmp" value in the Delay Compensation box in the Mix window on the record track and the cmp value should turn blue. This forces delay compensation on the track that is in input or record. Not sure if this is the issue, but it's worth trying.
Old 1st October 2018
  #11
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Uli Auer's Avatar
 

Hello everybody,

FYI: being in contact with Avid support regarding this issue they told me (after also asking me about the blue mode - which is not helping at all btw) that they could reproduce this and that it would be a known issue....and that there were already people working on getting this right....

Will let you know once there is news on their progress....

best regards,

Uli
Old 14th March 2019
  #12
Here for the gear
 

Quote:
Originally Posted by Uli Auer View Post
Hello everybody,

FYI: being in contact with Avid support regarding this issue they told me (after also asking me about the blue mode - which is not helping at all btw) that they could reproduce this and that it would be a known issue....and that there were already people working on getting this right....

Will let you know once there is news on their progress....

best regards,

Uli
Any updates since the fall? I'm still dealing with the same issues!
Old 14th March 2019
  #13
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Uli Auer's Avatar
 

Quote:
Originally Posted by dickyvmaas View Post
Any updates since the fall? I'm still dealing with the same issues!
Nope, not at all....although I need to say that I'm not much in the studio for some time now.....also did not install the latest version 2018.12....did you ?

Last update in my conversation with Avid CS was that there would be a "priority focus" (whatever that means) on fixing this issue referred to as "PT-228817"...

But that was mid december.....
Old 15th March 2019
  #14
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Quote:
Originally Posted by dickyvmaas View Post
Any updates since the fall? I'm still dealing with the same issues!
Update: Just started another ticket on Avid CS asking about the progress regarding this issue.....

Here's their reply:

Thank you for contacting Avid. Unfortunately bug PT-228817 is still unresolved. Rest assure that engineering is working on it. If you have any questions, give us a call at [...]

So that's what they call "high priority focus"....
Old 16th March 2019
  #15
Here for the gear
 

Quote:
Originally Posted by Uli Auer View Post
Update: Just started another ticket on Avid CS asking about the progress regarding this issue.....

Here's their reply:

Thank you for contacting Avid. Unfortunately bug PT-228817 is still unresolved. Rest assure that engineering is working on it. If you have any questions, give us a call at [...]

So that's what they call "high priority focus"....
Ha! Thanks for the update. I'll just be over here waiting for that focus, I suppose...
Old 17th March 2019
  #16
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T_R_S's Avatar
I am just wondering of the OP tried using Commit
Old 20th March 2019
  #17
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Uli Auer's Avatar
 

Sorry T_R_S.....but what's the point of your question ?

This issue has nothing to do at all with ITB bouncing / mix down....
Old 14th August 2019
  #18
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Pyxis360's Avatar
 

Same issue here I believe, on PT 2019.5 and Mojave 10.14.5. An Aux with a hardware insert cannot be printed in time. In realtime it's fine but if I try to record that Aux to free up the hardware it's out of time. I've made the compensation blue but to no avail.

The only thing that works is to physically patch a "dummy" Aux with another insert, and send everything to that BUT the Aux you want printed. Send that Aux straight out, then everything seems to line up.

Why you can listen in realtime and it's working but then just try to record that and it's out of time I have no idea.
Old 14th August 2019
  #19
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Pyxis360's Avatar
 

An empty project with nothing but a single track and a hardware insert, commit to track creates an out of time track

This must be a bug
Old 4 weeks ago
  #20
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Im a bit confused by this thread.

I have a hybrid setup as well. As soon as i introduce a summing mixer into the equation anything printed will be late. Not sure if this is what the o.p. is referring to. To get around this i set all of my outputs to 8 aux sub groups and route those outputs to the summing mixer. This was if i need to print anything with a hardware insert or record something new i simply switch the sub aux channel outputs to the main outs and temporarily bypass the summing mixer...and then switch back when done. This can be done very quickly with a few key commands.

I currently running 12.4 on hdx...dont know if this makes a difference.

I dont recall running into any timing issues when bouncing a aux channel with a hardware inserts in any scenario though.

ej
Old 4 weeks ago
  #21
Gear Head
 
Uli Auer's Avatar
 

Quote:
Originally Posted by ejsongs View Post
Im a bit confused by this thread.

I have a hybrid setup as well. As soon as i introduce a summing mixer into the equation anything printed will be late. Not sure if this is what the o.p. is referring to. To get around this i set all of my outputs to 8 aux sub groups and route those outputs to the summing mixer. This was if i need to print anything with a hardware insert or record something new i simply switch the sub aux channel outputs to the main outs and temporarily bypass the summing mixer...and then switch back when done. This can be done very quickly with a few key commands.

I currently running 12.4 on hdx...dont know if this makes a difference.

I dont recall running into any timing issues when bouncing a aux channel with a hardware inserts in any scenario though.

ej
Hi, O.P. here...;-)
Yes. That's exactly what this (still not being adressed yet after 10 months but still officially admitted by Avid Support as being a) bug is about... !
It has nothing to do with hardware inserts by the way, which work in a completely different way regarding processing and delay compensation....
Here we are talking about generally putting audio out thru D/A outputs - not making any difference whether that happens with one channel only or multiple channels going thru a summing mixer etc - and re-recording the signal back into ProTools AND (now comes the critical detail having an Aux fed by this A/D input but recording to an Audio track that gets its signal from that Aux track - instead of recording directly to an Audio track....THAT's the issue / bug.

The options "compensate for delay after record pass" in PT's I/O setup page are made for that exact purpose they are named after - the bug is that PT doesn't take into account that a signal that comes back in and just goes thru an Aux BEFORE reaching an Audio track it's supposed to be recorded on must be compensated the same way !

As I've said already, this bug is a "known issue" at Avid and hence

a) there can be no doubt about its existance and

b) I can't understand how the workflow you've described should change / help to avoid that problem....

I'm a little confused by your explanations and mixing up of several issues here....
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