Plug-in Delay Compensation broken with external side-chain

So frustrating ...

WHY can't they fix this ?

I have also reported the bug again to Apple. I've done this with every update. This is a serious issue that really renders the DAW unusable for me. How do we get Apples attention and people behind fixing this? Do we need to contact websites or video creators that get a lot of visibility in relation to Logic? Logic Pro Expert, etc.

I have also reported the bug again to Apple. I've done this with every update. This is a serious issue that really renders the DAW unusable for me. How do we get Apples attention and people behind fixing this? Do we need to contact websites or video creators that get a lot of visibility in relation to Logic? Logic Pro Expert, etc.

 

That's a good question, when I post about this in other places like a facebook group for Logic users nobody believes me that it's an issue. I try to explain or share a video but my guess is that some people are having issues with this and not realizing what the problem actually is.

I have also reported the bug again to Apple. I've done this with every update. This is a serious issue that really renders the DAW unusable for me. How do we get Apples attention and people behind fixing this? Do we need to contact websites or video creators that get a lot of visibility in relation to Logic? Logic Pro Expert, etc.

 

That's a good question, when I post about this in other places like a facebook group for Logic users nobody believes me that it's an issue. I try to explain or share a video but my guess is that some people are having issues with this and not realizing what the problem actually is.

 

Maybe with WWDC coming up that could be an opportunity? It's free for everyone and there may be sessions where we can get in contact with Logic devs directly.

Maybe with WWDC coming up that could be an opportunity? It's free for everyone and there may be sessions where we can get in contact with Logic devs directly.

I don't believe the Logic developers go to WWDC. And even if they went I can't imagine they would hold sessions to be in contact with end users. That's not really the point of the WWDC anyway.

Maybe with WWDC coming up that could be an opportunity? It's free for everyone and there may be sessions where we can get in contact with Logic devs directly.

I don't believe the Logic developers go to WWDC. And even if they went I can't imagine they would hold sessions to be in contact with end users. That's not really the point of the WWDC anyway.

 

Yeah true, I'll keep any eye out anyway. The approach of making this known to well viewed and popular logic platforms might help. Anyone have good examples of sites / channels to contact that get great visibility?

Anyone have good examples of sites / channels to contact that get great visibility?

Right here? Logic devs come here sometimes. Someone from the Logic team posted something here only a day or two ago.

Anyone have good examples of sites / channels to contact that get great visibility?

Right here? Logic devs come here sometimes. Someone from the Logic team posted something here only a day or two ago.

 

More places the merrier, us only talking about it here evidently isn't doing enough to make it a priority.

Right here? Logic devs come here sometimes. Someone from the Logic team posted something here only a day or two ago.

 

More places the merrier, us only talking about it here evidently isn't doing enough to make it a priority.

Straight to the source then: https://www.apple.com/feedback/logic-pro.html

 

More places the merrier, us only talking about it here evidently isn't doing enough to make it a priority.

Straight to the source then: https://www.apple.com/feedback/logic-pro.html

 

Yeah the more people we get submitting the issue here the better, I know a few of us here are consistently with each update.

Go for it. All hands on deck.

 

I don't believe the Logic developers go to WWDC. And even if they went I can't imagine they would hold sessions to be in contact with end users. That's not really the point of the WWDC anyway.

 

Yeah true, I'll keep any eye out anyway. The approach of making this known to well viewed and popular logic platforms might help. Anyone have good examples of sites / channels to contact that get great visibility?

 

I posted about it today on the facebook group called Apple Logic Pro Tech. I've posted about it before but this is the first time that people acknowledged that this problem exists. I think it's an education thing that a lot of Logic users don't know that it's an issue due to their workflow or because they don't know that the broken PDC is what's causing an issue.

 

There's another facebook page called Apple Pro X Users Group. I posted the broken PDC video there as well but got zero comments/feedback on it.

 

This thread on gearslutz has posted five pages of content about this issue since late January. https://www.gearslutz.com/board/apple-logic-pro/1295909-serious-old-bug-broken-pdc-completely-ignored-apple-logic-x-programmers.html?fbclid=IwAR3fFM65gX9no5nGCQlmj7Oz1V6glDjBAxOp0rQqX8kisFhkItiCKchHwXE

 

It feels like there's some momentum. I'm still game to keep educating Logic users that they should be frustrated and reaching out to Apple. The most recent video was really helpful to break it down for most Logic users.

I have also reported the bug again to Apple. I've done this with every update. This is a serious issue that really renders the DAW unusable for me. How do we get Apples attention and people behind fixing this? Do we need to contact websites or video creators that get a lot of visibility in relation to Logic? Logic Pro Expert, etc.

 

Maybe start a petition at change.org? Company's seem to pay attention to these.

 

Yeah true, I'll keep any eye out anyway. The approach of making this known to well viewed and popular logic platforms might help. Anyone have good examples of sites / channels to contact that get great visibility?

 

I posted about it today on the facebook group called Apple Logic Pro Tech. I've posted about it before but this is the first time that people acknowledged that this problem exists. I think it's an education thing that a lot of Logic users don't know that it's an issue due to their workflow or because they don't know that the broken PDC is what's causing an issue.

 

There's another facebook page called Apple Pro X Users Group. I posted the broken PDC video there as well but got zero comments/feedback on it.

 

This thread on gearslutz has posted five pages of content about this issue since late January. https://www.gearslutz.com/board/apple-logic-pro/1295909-serious-old-bug-broken-pdc-completely-ignored-apple-logic-x-programmers.html?fbclid=IwAR3fFM65gX9no5nGCQlmj7Oz1V6glDjBAxOp0rQqX8kisFhkItiCKchHwXE

 

It feels like there's some momentum. I'm still game to keep educating Logic users that they should be frustrated and reaching out to Apple. The most recent video was really helpful to break it down for most Logic users.

 

Nice! That's great, the more people are aware the better. Good job

I have also reported the bug again to Apple. I've done this with every update. This is a serious issue that really renders the DAW unusable for me. How do we get Apples attention and people behind fixing this? Do we need to contact websites or video creators that get a lot of visibility in relation to Logic? Logic Pro Expert, etc.

 

Maybe start a petition at change.org? Company's seem to pay attention to these.

 

Hmm yeah that might be an idea, would need to get a lot of people aware of the issue first so that the petition would get some traction behind it.

I have the issues as you've all described while using heavy latency plugins, pitch shifters, UAD, upsampling plugins etc. So, when I switch plugin latency in general prefs to "Audio and software instrument tracks" (instead of All), it fixes the sidechain issue, but off course then busses are off. Why would they include both these as options when niether solve the issues? I've submitted my bug report to apple again and now waiting patiently, but also weighing options with other DAW's. Good to see others are getting fed up with this as well. Hopefully they'll fix this soon.

I have the issues as you've all described while using heavy latency plugins, pitch shifters, UAD, upsampling plugins etc. So, when I switch plugin latency in general prefs to "Audio and software instrument tracks" (instead of All), it fixes the sidechain issue, but off course then busses are off. Why would they include both these as options when niether solve the issues? I've submitted my bug report to apple again and now waiting patiently, but also weighing options with other DAW's. Good to see others are getting fed up with this as well. Hopefully they'll fix this soon.

 

I'll keep using Logic for the current project but I should be fully transitioned over to Studio One 5 in about a month I hope. I'll be checking back here after updates and whenever Logic Pro 11 comes out.

( --- Thread was merged into here. Sorry, I didn't see this one --- )

 

So PDC on sidechained signals is broken. Since years.

Probably most of you know this already anyways, maybe not.

 

However I still want to address this as this doesn't seem to be that well known as it should be.

And is the only major thing that really ***** me off big time.

 

The .gif down here explains it better than I could write I think.

So please report this s*** to apple. Maybe someday they get their act together and fix this.

 

Here's the link to the apple logic pro feedback form:

https://www.apple.com/feedback/logic-pro.html

 

Here's the link to a gearslutz thread where a lot of details are clarified. Also the PDC Automation problem

is explained here as well, as PDC has actually 2 major issues...

https://www.gearslutz.com/board/apple-logic-pro/1295909-serious-old-bug-broken-pdc-completely-ignored-apple-logic-x-programmers-6.html#post14904457

 

For the people that still don't understand how significant this can get.

I made a .gif where elastique pitch gets the sidechain signal from inst1, you don't even need to hear the audio, you can SEE how far off the sidechain signal is.

In case the image doesn't work, just use the link. You can easily test this yourself by using a plugin that introduces quite some latency and has a sidechain input.

 

 

Best,

tL.

 

 

( --- Thread was merged into here. Sorry, I didn't see this one --- )

Noticed that Plugin (or any) Delay Compensation isn't applied when monitoring input (audio or MIDI). This made me think that the PDC on Logic might not be done at 'online' or 'audio engine runtime' level, but is simply done by adjusting the read timing of channel source data, so that eventually channel outputs end up in sync with each other at summing/output stages, but only after going through their entire signal chains/routes.

 

This would be more like a design flaw, not a bug, and fixing this would propably require a rewrite of the Logic audio engine itself. At least in situations, where signals need to be in sync before the final output.

 

While monitoring live inputs through Logic, it seems that Logic just doesn't have the required compensation mechanism, and the signals just pass through, as Logic can't adjust the read timing of live input. If individual chanels and/or their routes have different latencies, the output will then be out of sync. In this respect, auxes and sidechain inputs are also just monitoring their sources 'live'.

 

The 'proper' way to deal with this propably would be (instead of relying on compensated the raw data read timing) to hold the data (that needs to be PDCd/delayed) in an extra memory buffer during audio engine 'runtime'. The data in memory buffer can be accessed in sync at any 'latency stage' during the audio engine runtime, by adjusting read timing from this memory buffer at the sidechain input/monitoring end. Trade-off being increased use of memory and lower maximum track count. If 100 channel inputs need to be monitored in sync, and one of them has latency inducing plugin, then the 99 other channels need to be held in a memory buffer until the channel with latency has finished filtering/processing.

 

But now, the Delay Compensation seems to work only at 'visual' level in Logic. 'What you see on Main window tracks is what you get at final output stage'. The signals flowing through their routes may not always be in absolute sync, and when this is required (sidechainin), Logic doesn't seem to have any mechanism to derive the amount of compensation needed at different points ('nodes' ) from it's own signalchains/routes.

 

A simple test on video:

 

2 channels/audio tracks.

 

Both with identical content.

 

Put a compressor on channel 1, and sidechain it to channel to 2.

 

Set the compressor to Platinum 1:1.

 

Put a Linear Phase EQ on chanel 1, after(!) the compressor.

 

Listen to sidechain input on compressor, while comparing it to channel 2.

 

It is out of sync. Even though the latency is introduced after(!) the compressor and it's sidechain input, and the tracks seem to visually be in perfect sync on timeline. This would be because instead of delaying the post-fader output ('write') of channel 2 to match channel 1 latency (would require memory buffering), Logic apparently just delays the absolute input ('read') of channel 2 data to match the latency.

 

In this case, when listening to the sidechain input on channel which later induces latency, the already delayed-at-read sidechain input signal goes through the Linear Phase EQ, and gets delayed by it's processing latency, resulting in sync offset between channel 1 & 2.

 

In other words, the sidechain input signal is already compensated for the Linear Phase EQ latency, even though it arrives in the compressor before the Linear Phase EQ.

 

Move the compressor behind the Linear Phase EQs and repeat the experiment. Notice, that now they are in sync. Because the listened sidechain input no longer goes through the Linear Phase EQs, and is the same delayed input signal heard from channel 2. In this situation both signals are delayd to compensate for the Linear Phase EQ latency, but neither of them goes through the LPE, so they are heard in sync, but with unnecessary delay compensation.

 

Mute channel 2, turn off sidechain input listening and enable sidechain input, and experiment with some compression settings. Then move the compressor back in front of the Linear Phase EQs. The sound changes. In the video the compressor now misses the kick attack completetly. Because the timing of the compressor input signal to be processed depends on the latency of the Linear Phase EQs, but the sidechain input timing is fixed based on the needed total latency compensation amount.

 

User doesn't even need to setup complex routings with auxes and sidechaining to suffer from this. Simple reordering of sidechained plugins can 'break' the sidechain input sync.

 

Repeat experiment in Ableton Live, and notice that it works perfectly (later part of video).

Edited June 27, 2021 by en5ca

Fingers crossed this is fixed in the 10.6 update mentioned on apple.com

Doesn’t appear to be

Was just coming back to ask. How is this still not fixed?

I don't see this bug mentioned in the new 10.6 release?

 

I can't test for myself since I'm not going to switch to Catalina (from Mojave) right now, and 10.6 is ≥Catalina only.

I don't see this bug mentioned in the new 10.6 release?

 

I can't test for myself since I'm not going to switch to Catalina (from Mojave) right now, and 10.6 is ≥Catalina only.

 

It is still there.

sigh

Will this ever be fixed or do we just move to Reaper at this stage? It renders using so many plugins useless.

Hi i just read the thread and have found sort of a solution. It seems that the Linear Phase EQ has so much latency that it will distort your project. So if you sidechain with a compressor put it after the EQ also you can now change the PDC from Off and All to Audio and Software instrumented tracks. Not sure if it helps but it ''fixed'' my problem.

Not fixed in 10.6, reporting a bug again. Maybe we should contact telephone support more often with this?

Not fixed in 10.6, reporting a bug again. Maybe we should contact telephone support more often with this?

I don't think it matters how often you contact telephone support about bugs. Instead, I would recommend you report it (again?) at https://www.apple.com/feedback/logic-pro.html

Reported three times. I think we should start a petition at change.org

Which post has the most summarized and informative description of the bug?

And we should attach two most clear videos with the bugs for ADC & PDC problems, I think.

Then post a link to all topics regarding Logic's ADC & PDC on all forums and maybe in the header of this site and forum?