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Plug-in Delay Compensation broken with external side-chain


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this is exactly the scenario i mentioned in my previous comment:

 

The only thing that doesn't work well is if you have a sidechain processor on bus and you add a latency-inducing plugin after. Also Bounce in place.

 

 

If you don't add a latency-inducing plugin after side-chained plugin, it works fine. so it is better, but it's still not perfect.

 

I actually got a direct response from apple after submitting feedback yesterday so i'll send them this video and I also need to enclose the project - first one for me.

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this is exactly the scenario i mentioned in my previous comment:

 

The only thing that doesn't work well is if you have a sidechain processor on bus and you add a latency-inducing plugin after. Also Bounce in place.

 

 

If you don't add a latency-inducing plugin after side-chained plugin, it works fine. so it is better, but it's still not perfect.

 

I actually got a direct response from apple after submitting feedback yesterday so i'll send them this video and I also need to enclose the project - first one for me.

 

But what is the case for me when the latency intrusion plugin IS the side chain plugin (soothe 2 for example)

For me it's broken.

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What I isolated yesterday is that when a latent plugin in an aux is used, and then that aux is fed to a bus which is used as side chain input....then the side chain input causes PDC to go out of sync. But it could certainly be possible if the latent plugin is after it might cause it too, but side chain was a key factor...but in my view...its specifically when its being used with an AUX signal chain involved with feeding the side chain. I think the feeding of the side chain causes LogicPro to ignore the latency o on that AUX chain that is feeding it.

 

The problem with side chain does NOT occur if the feeding of the side chain comes from a latent plugin on an audio channel. I believe that is because LogicPro handles audio channel latency by feeding region data to it early in order to compensate...so the problem is fixed, in that case, before hitting the side chain. But in the case of AUX channel PDC, LogicPro adjusts things by making other channels be delayed to match the latent AUX... so in any case for whatever the reason, if you have a latent AUX...and feed it to side chain, LogicPro decides to ignore the latency on the AUX channel...and then doesn't delay the other channel that is being fed the sidechain...like it normally would for normal AUX channel PDC. The side chain itself is the trigger to the problem, but the problem is also highly related to AUX signal chains and the way PDC works with them.

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this is exactly the scenario i mentioned in my previous comment:

 

The only thing that doesn't work well is if you have a sidechain processor on bus and you add a latency-inducing plugin after. Also Bounce in place.

 

 

If you don't add a latency-inducing plugin after side-chained plugin, it works fine. so it is better, but it's still not perfect.

 

I actually got a direct response from apple after submitting feedback yesterday so i'll send them this video and I also need to enclose the project - first one for me.

 

Great! Keep us posted. Hopefully we don’t have to wait another 3 years for a fix.

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if someone also wants to submit a bug report to apple, here are the steps to reproduce the problem

 

"Logic side-chain bug"

 

create track “audio 1”

create track “audio 2”

 

route track “audio 1” over “bus 1” to “aux 1”

insert latency inducing plugin “Linear Phase EQ” into “aux 1”

route “aux 1” over “bus 2” to “aux 2”

 

route track “audio 2” over “bus 3” to “aux 3”

 

insert plugin “Compressor” to “aux 3”

change side chain of the compressor to “bus 2”

 

put a identical drum-loop on both tracks

 

result:

audio 1 <-> audio 2 are NOT in sync

Make this modification to sync the audio.

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if someone also wants to submit a bug report to apple, here are the steps to reproduce the problem

 

"Logic side-chain bug"

 

create track “audio 1”

create track “audio 2”

 

route track “audio 1” over “bus 1” to “aux 1”

insert latency inducing plugin “Linear Phase EQ” into “aux 1”

route “aux 1” over “bus 2” to “aux 2”

 

route track “audio 2 over “bus 3” to “aux 3”

 

insert plugin “Compressor” to “aux 3”

change side chain of the compressor to “bus 2”

 

put a identical drum-loop on both tracks

 

result:

audio 1 <-> audio 2 are NOT in sync

Make this modification to sync the audio.

 

Personally, I think it's easier to insert one or more sample delays on aux 3 and dial in the required delay, than creating another bus, moving your EQ there and then dialling that bus in.

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That's another interesting datapoint!

 

I think in that example you could have just put the send on the original audio track also...same difference, but good to know it would work from the Aux also. The good thing about this solution vs manually inserting sampleDelay is that you don't have to know how much latency and figure it out manually. You're basically just somehow causing LogicPro to do its job properly in terms of PDC. I'm more interested right now in coming up with data points that will help Apple fix the problem per say, then figuring out how to work around it. It sounds like Apple really wants to fix this right now so hopefully we will not have to worry about it again after 10.6.3 :-), but still if we can gain any insights that will help them understand the bug and fix it...what information can we decipher from this?

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That's another interesting datapoint!

 

I think in that example you could have just put the send on the original audio track also...same difference, but good to know it would work from the Aux also. The good thing about this solution vs manually inserting sampleDelay is that you don't have to know how much latency and figure it out manually. You're basically just somehow causing LogicPro to do its job properly in terms of PDC. I'm more interested right now in coming up with data points that will help Apple fix the problem per say, then figuring out how to work around it. It sounds like Apple really wants to fix this right now so hopefully we will not have to worry about it again after 10.6.3 :-), but still if we can gain any insights that will help them understand the bug and fix it...what information can we decipher from this?

 

Yes, I suppose the sample delay is ok for a simple project, but the calculations could become mind boggling for a large one.

 

The fact that Apple has replied to two of us so far is quite promising. Let’s hope it gets sorted this time.

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Hope the fix works, i'm using Ableton Live right now and while PDC is top notch, the one second delay (even at buffer 128) everytime i press PLAY is really killing the vibe.

I think that is the unfortunate side effect of the buffering required for PDC to be done properly in case of latency inducing plugins. It takes extra time, memory and CPU power, and usually a relatively large amount.

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  • 1 month later...

Can anyone confirm the fix does or does not completely work?

 

I'm still on Catalina and am generally hesitant to update, but I'll be hitting a point next week where everything I'm working on is wrapped up, so if this fix works its a good time to upgrade.

 

With the current set of projects I've done all the sidechaning on individual tracks like I used to, which is a bit more hassle and not quite as congruent sounding, but not as much hassle as it breaking on a bus 3/4ths through a project.

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Can anyone confirm the fix does or does not completely work?

 

I'm still on Catalina and am generally hesitant to update, but I'll be hitting a point next week where everything I'm working on is wrapped up, so if this fix works its a good time to upgrade.

 

With the current set of projects I've done all the sidechaning on individual tracks like I used to, which is a bit more hassle and not quite as congruent sounding, but not as much hassle as it breaking on a bus 3/4ths through a project.

 

Keep the 10.6.1 version and upgrade.

Use 10.6.1 for old projects sidechained with 10.6.1.

Use 10.6.2 for new projects.

 

There's a difference in latency fixing algorithm for 10.6.1 vs 10.6.2.

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dear I am having this problem even today with logic 10.6.2, while sidechaining vocal on the synths bus with track spacer 2.5

 

can someone advise and I wish to know whether it has been resolved or not

 

It seems the base case of two tracks side-chained to each other has been solved when no bussing is involved, but problems persists with busses and there might even be some new bus related problems too.

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  • 4 weeks later...

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