Basic plugin latency question

[czh]

I have a really basic question about plugin latency. In a plugin where the UI is showing the waveform of the audio on a track, or showing a visual representation of how that plugin is acting on a track, does a discrepancy between what I see in the UI and what I hear indicate actual latency in the way the plugin is working? For example, I'm using soothe2 as a de-esser on a track. When I open the soothe2 window and watch what it's doing, it doesn't match up with the obvious esses I'm hearing, but it does show that soothe2 is doing something. I see a big reduction in the affected frequencies, and then a second later I hear the ess in question. Turning the plugin off does sound different than having it on, which seems to indicate that it's working at least partially, but obviously for something like a de-esser to work at 100% effectiveness it really requires exact sync, and I don't trust my ears that much (yet).

Is there a chance that Logic's latency compensation means that all audio is delayed and in sync and plugins are working as intended, but the UI is showing non-compensated info so looks to be ahead? And if that is true, then...why not delay the UI too?

I'm using an Apollo Twin on an M1 Mini. This project has about a dozen audio tracks and about a dozen aux tracks, and I think my plugin usage is in a normal range. I'm not having any other performance issues.

Thanks!

[des99]

On 8/4/2022 at 3:15 AM, czh said:

In a plugin where the UI is showing the waveform of the audio on a track, or showing a visual representation of how that plugin is acting on a track, does a discrepancy between what I see in the UI and what I hear indicate actual latency in the way the plugin is working?

Generally, no.

Remember, the plugin is processing the audio *as Logic gives it the data*, but you are *hearing* the audio, *after* the audio has left the plugin, and potentially further delayed due to latencies of all the other busses and plugins on your system, so they can all line up at the output.

Simple example - say you have one track with Soothe on it, and an Adaptive Limiter on your output channel, which adds half a second of latency.

When you watch Soothe, it's visual display won't line up with what you hear, because what you hear has been delayed half a second *after* the plugin processed that audio. It's complex, depending on a typcial project, what plugins and routings are used, and the various methods Logic employs to deal with the various latencies involved.

But mostly, the discrepancies between what you see and what you hear are the result of all the latencies combined in your project going on, and the plugin processing that data doesn't know anything about what's going on elsewhere - it's just working on the buffers of samples given to it by Logic.

[czh]

Only just seeing this. Thank you!