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  #1  
Old 08-20-2018, 12:03 PM
freakhouse freakhouse is offline
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Default H/W buffer size latency

I've got a HDX rig with latest version of PT 2018. I have had this issue for a while and never have been able to find a solution.

For mixing I run 7 stereo masters out to a Dangerous 2 Bus summing box and then return the summed signal back into a Stereo aux which is then routed to a final mix audio track in input record. Delay compensation is on but disabled for the aux and the final mix audio track. This works great. To clarify, each of the 7 stereo masters has a stereo submix of drums, bass, gtrs, etc.

The problem is if I need to raise the H/W buffer size with a high plugin count then the tracks go out of sync.

Seems like this would be an easy fix, no? Any help would be appreciated.
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Old 08-20-2018, 01:53 PM
BScout BScout is offline
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Default Re: H/W buffer size latency

What's your audio interface attached to the HDX card?

Turn on delay comp for your aux/print tracks (blue mode)
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Old 08-20-2018, 04:37 PM
freakhouse freakhouse is offline
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Default Re: H/W buffer size latency

My interface is an Avid HD I/O.

Turning on delay compensation on print tracks doesn't fix the problem. I don't know why it would. The mix is being summed analog and then coming back into stereo inputs on the interface. Those tracks aren't running parallel to anything they would need to be in sync with. Correct me, if I'm missing something there.
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Old 08-20-2018, 05:11 PM
BScout BScout is offline
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Default Re: H/W buffer size latency

My assumption is the tracks are out of sync before going to your hardware outputs to your summing box and so are returning the same way (out of sync.)

Instead of using your summing box, have you tried to see what happens if you sum internally? Or print the stems going to your summing box and hear what they sound like going out all the same (monitoring) output?
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  #5  
Old 08-20-2018, 06:49 PM
685 685 is offline
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Default Re: H/W buffer size latency

What particular tracks are out of sync?
The individual audio tracks with each other?

or the re-recorded summed track (out of sync with the individual tracks)?




Also, what made you use 7 stereo masters instead of creating 7 stereo AUX/BUS tracks?
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Old 08-20-2018, 08:44 PM
LukeHoward LukeHoward is offline
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Default Re: H/W buffer size latency

Quote:
Originally Posted by freakhouse View Post
My interface is an Avid HD I/O.

Turning on delay compensation on print tracks doesn't fix the problem. I don't know why it would. The mix is being summed analog and then coming back into stereo inputs on the interface. Those tracks aren't running parallel to anything they would need to be in sync with. Correct me, if I'm missing something there.
Do you have any plugins on the channels that feed those masters? You need to compensate for those delays, so you should enable delay compensation.

The other issue is compensating for the converter latency when you go to and from your summing mixer, if you want the stereo mix to line up exactly with the source tracks (e.g. for A/B'ing). If I remember correctly, converter latency is only compensated for when using hardware inserts. So I'm not sure what the easiest way around this is, although it will just be a handful of samples so shouldn't be noticeable unless you're trying to combine the summed tracks with the non-summed ones. (Edit: which you state you're not.)
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Old 08-22-2018, 12:46 PM
freakhouse freakhouse is offline
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Default Re: H/W buffer size latency

Figured out the issue. Delay compensation was turned off on a track. Only seemed to be noticeable at those higher buffer settings.
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Old 08-22-2018, 04:10 PM
albee1952 albee1952 is offline
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Default Re: H/W buffer size latency

Keep in mind that plugin delay on any Master tracks are not compensated for. If you have plugins on your Masters, make them all match and bypass what isn't needed so all Master tracks have the same latency
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Old 08-22-2018, 04:34 PM
freakhouse freakhouse is offline
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Default Re: H/W buffer size latency

Quote:
Originally Posted by freakhouse View Post
Figured out the issue. Delay compensation was turned off on a track. Only seemed to be noticeable at those higher buffer settings.
Can anyone tell me why delay compensation being off on a single track would be way more noticeable at a higher buffer setting? Just curious.
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Old 08-23-2018, 04:57 AM
dtmprod dtmprod is offline
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Default Re: H/W buffer size latency

Quote:
Originally Posted by freakhouse View Post
Can anyone tell me why delay compensation being off on a single track would be way more noticeable at a higher buffer setting? Just curious.
Latency is usually proportional to the sample setting. Going from 128 to 256 means the latency at 256 is double what it was at 128. If you're switching from 128 to 512, its gonna be 4 times as much latency. And so on....
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