Low latency mode: What is the meaning of orange sends, and other questions [SOLVED]

[alexe]

Alright, I think thanks to

I've finally understood how Logic's low latency mode behaves: If there is any latency-inducing plugin anywhere in the signal chain, Logic will not only bypass that plugin, but it will also route the track to be recorded directly to the outputs, skipping over any routing in between. I've tested this and noticed a few things that still confuse me:

 

1. The sends always turn orange in low latency mode, regardless of whether or not they are bypassed. Hence the question: What is the meaning of the sends turning orange? When I remove all latency-inducing plugins from the signal chain, I can suddenly hear that reverb again that I have on that one auxiliary track, but the send to it is still orange. What's the point of that?

 

2. Apparently deactivating a latency-inducing plugin is not sufficient for Logic to consider it gone from the signal chain, but rather one needs to remove the plugin entirely from the track. Is that correct or is something weird going on in my case? When I deactivate all latency-inducing plugins in the signal chain, Logic still skips over all my routing and goes straight to the outputs in low latency mode, but when I remove said plugins instead, the routing is not skipped.

 

3. Out of curiosity, in case anybody knows: If low latency mode bypasses all latency-inducing plugins, then why does Logic - on top of that - also skip all further routing and go straight to the outputs? One would think that once the latency-inducing plugins are bypassed, there is no need to skip any routing?

Edited February 11, 2022 by alexe

[David Nahmani]

1. An orange send indicates you're not sending that specific track to that specific send.

2. That's correct, unless you use Low Latency Mode which can take care of that for you without having to remove the plug-in. If it were not working like that you couldn't automate the On/Off button of a plug-in without creating hiccups in the audio signal's time synchronization.

3. It skips any routing that would create latency, such as any bus routing that would lead your signal down a path where it needs to be delayed by plug-in delay compensation in order to be sync'ed up with other streamed that are themselves delayed by latency inducing plug-ins.

[alexe]

1. An orange send indicates you're not sending that specific track to that specific send.

2. That's correct, unless you use Low Latency Mode which can take care of that for you without having to remove the plug-in. If it were not working like that you couldn't automate the On/Off button of a plug-in without creating hiccups in the audio signal's time synchronization.

3. It skips any routing that would create latency, such as any bus routing that would lead your signal down a path where it needs to be delayed by plug-in delay compensation in order to be sync'ed up with other streamed that are themselves delayed by latency inducing plug-ins.

 

Thanks for your help David, but I'm still confused (but a bit less already at least ) and one thing you say seems to contradict with what I'm experiencing.

 

1. As I explained in my original post, the track in question displays an orange send that leads to an aux channel that has a reverb on it. I can hear the reverb despite the send being orange, and I can hear the difference between switching the reverb on and off on the aux channel. This means the signal is clearly being routed through that aux channel despite the send on the originating track being orange, so an orange send cannot indicate that this send is inactive as you suggest. What you suggest would make total sense in theory, but it's not what I'm seeing.

 

2. I understand your second sentence, but not the first. The second sentence makes sense to me: A latency-inducing plugin induces latency even while deactivated, because otherwise you couldn't turn the plugin on and off without time sync hiccups. Thanks a lot for this insight, it's totally logical but I had never thought about it before! However, what do you mean by low latency mode being able to "take care of that for you without having to remove the plugin"? In low latency mode it still isn't sufficient to deactivate the latency-inducing plugins in order to prevent Logic from also skipping over all the remaining, non-latency-inducing plugins. There, too, I need to remove the latency-inducing plugins entirely (which makes sense knowing the explanation from your second sentence).

 

A very key insight for me is that a plugin that induces latency does so even while inactive. Thanks for this! I think the Logic user manual should make this point much clearer (or make it at all, for that matter), because knowing this is really critical in order to understand the behavior of low latency mode.

[David Nahmani]

1. You're right. What the orange send actually means is that the signal will be routed through the signal chain where that bus is routed only if that results in less latency than what your audio preferences are set to, otherwise the amount of signal sent to the bus will not be routed to that bus but instead routed straight to your Stereo Out so that you can hear it.

 

2. In low latency mode there's no need to turn off or remove the plug-in at all, the signal just bypasses the plug-in completely which means the plug-in does not add latency. Isn't that what you're experiencing?

 

I've been experimenting with various set ups for a while to try to answer your question and through my experimentations I've found that you'll get a funny (a.k.a. buggy) behavior if you start messing with your plug-ins while a track is R-enabled and you're in low-latency mode. To make sure you truly get the expected behavior, you'll want to stop touching any of the plug-ins, restart the core audio engine (in Logic's audio preferences, deselect and reselect the Core Audio checkbox, then close the pref window), and R-enable the track again.

[alexe]

2. In low latency mode there's no need to turn off or remove the plug-in at all, the signal just bypasses the plug-in completely which means the plug-in does not add latency. Isn't that what you're experiencing?

 

Ah yes, that is what I'm experiencing, there was just a slight misunderstanding here. I know understand the first sentence of your previous statement . What I had meant is that even if the latency-inducing plugins are disabled, low latency mode still skips over the remaining active, non-latency-inducing plugins, too. One would need to remove the latency-inducing plugins from the signal chain entirely to make low latency mode at least process the non-latency-inducing plugins, merely deactivating them isn't enough (which, once again, makes sense after what you explained).

 

While this totally makes sense now, it's still kind of unfortunate from a workflow perspective. Say I have a bunch of plugins on my stereo output channel. If only one of them introduces latency, then low latency mode will skip over the entire chain, even if I deactivated that one latency-inducing plugin. So there is no convenient way of bypassing only the latency-inducing plugins but not all the rest. But I guess that's just how it is

[David Nahmani]

One would need to remove the latency-inducing plugins from the signal chain entirely to make low latency mode at least process the non-latency-inducing plugins, merely deactivating them isn't enough (which, once again, makes sense after what you explained).

Right! Wow I don't know if I'm tired but it took me a couple of re-read to grasp that sentence as well.

 

While this totally makes sense now, it's still kind of unfortunate from a workflow perspective. Say I have a bunch of plugins on my stereo output channel. If only one of them introduces latency, then low latency mode will skip over the entire chain, even if I deactivated that one latency-inducing plugin. So there is no convenient way of bypassing only the latency-inducing plugins but not all the rest. But I guess that's just how it is

Actually the Stereo Out is the one channel strip where it works the way you want: it bypasses the plug-ins that would be responsible for adding too much latency to the signal path but not the others. I just tested this with an Adaptive Limiter and an Amp Designer, the Adaptive Limiter is bypassed but I can hear the Amp Designer.

[alexe]

Actually the Stereo Out is the one channel strip where it works the way you want: it bypasses the plug-ins that would be responsible for adding too much latency to the signal path but not the others. I just tested this with an Adaptive Limiter and an Amp Designer, the Adaptive Limiter is bypassed but I can hear the Amp Designer.

 

Oh, right! I've just tried this myself several times in a row and the first time it didn't work and the other times it did. The one thing that's weird in this case: The bypassed plugins on the output channel do not turn orange for me. As I turn on low latency mode with a latency-inducing plugin on the output channel, nothing changes visually on the output channel strip. The latency-inducing plugin is skipped from the processing, but its insert slot is still blue. Is it the same for you?

[David Nahmani]

The one thing that's weird in this case: The bypassed plugins on the output channel do not turn orange for me. As I turn on low latency mode with a latency-inducing plugin on the output channel, nothing changes visually on the output channel strip. The latency-inducing plugin is skipped from the processing, but its insert slot is still blue. Is it the same for you?

Yes, that's normal, there's no visual indication that your live signal stream is bypassing that plug-in.

 

The plug-in does not turn orange because it is not disabled: it is still processing all other audio signals, only the live signal from the R-enabled track is bypassing that plug-in.

[alexe]

Oh, right! Thank you so much!

[David Nahmani]

You're welcome!

[keano12]

I am running into this too when I don't believe I had this happen before with this particular plugin. Wonder why its happening now? I was able to sing and hear it with low latency on. Low Latency Safe Mode isn't showing wither odd. It is 1 plugin on the track which I know I sang through in another song.

Edited February 18 by keano12