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Plug-in Delay Compensation broken with external side-chain


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I'm very hands off with Logic these days, moved to Reaper last year but I still check in now and then. From what I'm reading 10.6.3 sounds nearly like a step backwards. Anyone tried out the 10.7 update?

According to release notes, nothing has been done.

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I'm very hands off with Logic these days, moved to Reaper last year but I still check in now and then. From what I'm reading 10.6.3 sounds nearly like a step backwards. Anyone tried out the 10.7 update?

According to release notes, nothing has been done.

 

Very disappointing to hear, oh well.

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PDC seams to be broken even without sidechain now:

 

Here Just 2 channels of Alchemy.

 

One Panned to hard right the othet hard left.

 

On one I added adaptive Limiter with 200ms Lookahead, to make tging obvious:

 

Unfortunately that seems to be the desired behaviour of Logic when monitoring live inputs through software. Basically making 'record what you hear' impossible with mixed latency input sources.

 

viewtopic.php?f=42&t=152855

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For Virtual Instruments either ?

 

And how do you play a track stack instrument which contains effects which introduce latency ...

 

I doubt that this is intended

 

Simple. You don't, at least in sync. But agreed, that probably isn't what they intended, but it's what has been accepted. That's been an issue since early versions of Logic Pro X.

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Here another Example. Essentially it is the same example as the previous, but this time I wanted to check how sidechain 'meanwhile' behaves.

The result is quite 'funky' to formulate it in a political way.

 

So I added one Alchemy playing a pad sound

On thet Track there is a Compressor.

 

Its Sidechaininput is set to another channel with the kick drumsynth on it.

Playback sound Ok to me.

But here come the funkines.

 

Live playback of all other tracks are now behave as expected!

 

Once I remove the Sidechain Input it get's broken as in the previous videos I showed.

 

It would seem without the sidechain connection Logic would operate like Ableton Live does when 'Reduce Latency When Monitoring' is enabled in Live; disabling PDC on monitored input tracks. Although, if you record that, with Logic, you will end up with aligned MIDI notes on different tracks in same non-compensated positions, or aliased reagions, making it impossible to playback like it was heard through monitoring during recording.

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For Virtual Instruments either ?

 

And how do you play a track stack instrument which contains effects which introduce latency ...

 

I doubt that this is intended

 

Simple. You don't, at least in sync. But agreed, that probably isn't what they intended, but it's what has been accepted. That's been an issue since early versions of Logic Pro X.

 

Isn't this an issue with a lot of DAWs though? In some DAWs I could have sworn they just deactivate some of the routing when you monitor to prevent this. Mainly asking because I'm trying to keep track of what to avoid in my mixes and most of the stuff earlier in the thread I would run into was fixed throughout 10.6.

 

Also, doesn't Low Latency mode help one work around this by disabling the plugins that cause that latency?

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Also, doesn't Low Latency mode help one work around this by disabling the plugins that cause that latency?

Yes it does. Anyways is the behavior quite unexpected.

 

?! PDC works for live played instruments when a compressor has a sidechain assiinged to it ?!

?! If we remove that sidechain input live played instruments are no longer compensated ?!

 

Something like this is essential to know, especially when having a huge project.

Thing like this can be tricky to find out and solve.

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Isn't this an issue with a lot of DAWs though? In some DAWs I could have sworn they just deactivate some of the routing when you monitor to prevent this. Mainly asking because I'm trying to keep track of what to avoid in my mixes and most of the stuff earlier in the thread I would run into was fixed throughout 10.6.

 

Also, doesn't Low Latency mode help one work around this by disabling the plugins that cause that latency?

That depends on the DAW, and it's 'Low Latency Mode' implementation. Cubase doesn't change the routing, but it bypasses latency inducing plugins from monitored input signal chain to minimize latency while maintaining sync. Ableton and REAPER don't change the routing, they offer the ability to disable PDC for monitored inputs to reduce latency. Studio One and AFAIK Pro Tools bypass plugins and further routing. Logic seems to do all three in Low Latency Mode: bypass plugins, bypass routing and disable PDC in some cases, as shown in ansolas' video.

 

This is perhaps slightly off topic, but regarding to input monitoring the problem with Logic is it does not offer discreet control over PDC while monitoring inputs, and in any case, doesn't properly compensate the monitoring latency to software monitored inputs with or without Low Latency Mode when recording. As shown in ansolas' video, creating the sidechain connection seems to enable PDC on all input monitored tracks without informing the user, or informing that PDC was disabled for monitored inputs in the first place (when in fact it is enabled in the preferences); this should be a global or track preference option, and not depend on the routing.

 

There are some examples on this thread where sidechain PDC isn't working during normal playback in Logic, even after the fix, and when input monitoring is not involved at all. At least Ableton, Cubase and REAPER are able to handle this correctly: maintain sync during playback and recording with software monitoring, compensate recording positions for monitoring latency, and offer user control over whether to use or constrain PDC or not (or bypass plugins/routing) to reduce monitoring latency.

 

What I know to be fixed with Logic is that reordering plugins no longer affects sidechain PDC, and sidechain PDC should work between tracks inside same submix or directly routed to master. What (I think still) should be avoided is sidechaining between different 'layers' or 'depths' of tracks/submixes/buses/groups/stacks/etc when different plugin latencies are involved.

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[praise]

This fader here turns out to be very useful:

 

 

 

909481547_Screenshot2021-10-21at13_27_44.thumb.png.7fc3dd874767d6e9f0d360227d17a7a3.png

 

It lets me easily see in teh muxer which channels exceed the latency threshold.

 

<3

[/praise]

 

So once set to 0 ms you can easily determine the zero latenzy plugins

 

And teh best, LowLatency mode excludes plugins on teh master :)

That way Realphones or ARC3 kept unaffected

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In Logic Pro, you can choose to apply plug-in latency compensation either to all channel strip types, or to only audio and software instrument channel strips:

 

Audio and software instrument channel strips only: If you insert latency-causing plug-ins only on audio and instrument channel strips, you can choose plug-in latency compensation for only audio and instrument tracks. Logic Pro achieves this by delaying audio and MIDI regions on audio and instrument tracks. This results in snappy playback performance.

 

All channel strip types: If you insert latency-causing plug-ins on aux or output channel strips, you can choose plug-in latency compensation for all types of channel strips. When this setting is turned on, Logic Pro compensates for latency-causing plug-ins by calculating the amount of latency caused by all plug-ins, and then delaying audio streams by an appropriate amount. This type of plug-in latency compensation can result in a slight lag in playback performance, depending on how much latency is being compensated.

 

This is quote from revised(?) Logic Pro 10.7 manual. Now the description of PDC compensation for all channel strip types seems to be correct; delaying individual audio streams between nodes (plugins, split points, etc), causing 'extra lag' to maintain sync. Haven't tested 10.7 yet to see if this has been implemented properly.

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In Logic Pro, you can choose to apply plug-in latency compensation either to all channel strip types, or to only audio and software instrument channel strips:

 

Audio and software instrument channel strips only: If you insert latency-causing plug-ins only on audio and instrument channel strips, you can choose plug-in latency compensation for only audio and instrument tracks. Logic Pro achieves this by delaying audio and MIDI regions on audio and instrument tracks. This results in snappy playback performance.

 

All channel strip types: If you insert latency-causing plug-ins on aux or output channel strips, you can choose plug-in latency compensation for all types of channel strips. When this setting is turned on, Logic Pro compensates for latency-causing plug-ins by calculating the amount of latency caused by all plug-ins, and then delaying audio streams by an appropriate amount. This type of plug-in latency compensation can result in a slight lag in playback performance, depending on how much latency is being compensated.

 

This is quote from revised(?) Logic Pro 10.7 manual. Now the description of PDC compensation for all channel strip types seems to be correct; delaying individual audio streams between nodes (plugins, split points, etc), causing 'extra lag' to maintain sync. Haven't tested 10.7 yet to see if this has been implemented properly.

 

Interesting. With a thread this long, it’s getting hard to parse which issues were fixed, which weren’t, which routing configs to avoid. I almost wonder if after 3 years it should have a 10.7 thread for whatever’s left.

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Here another Example. Essentially it is the same example as the previous, but this time I wanted to check how sidechain 'meanwhile' behaves.

The result is quite 'funky' to formulate it in a political way.

 

So I added one Alchemy playing a pad sound

On thet Track there is a Compressor.

 

Its Sidechaininput is set to another channel with the kick drumsynth on it.

Playback sound Ok to me.

But here come the funkines.

 

Live playback of all other tracks are now behave as expected!

 

Once I remove the Sidechain Input it get's broken as in the previous videos I showed.