How to even up latency between tracks/effects

Report · Nov 07, 2023

I've been using a Soundcraft UI24R mixer along with Audition to create a mix to a livestream. Soundcraft provides a Multi-Channel USB Audio Driver for Windows, which is basically the ASIO for that mixer. I'm using the latest version of Auditon and the latest version of that driver.

That ASIO driver exposes all 32 channels from the mixer as microphone inputs. I'm using about 20 of them to create the mix (drum kit, guitars, microphones, etc.), as shown in the picture below. I then set them all to record and activate the "I" (monitor) button on each channel (smart monitoring is off under Preferences -> multitrack). I then use reastream to send that audio mix to OBS. I understand there are multiple points of latency with that, but that's not my concern (I can always delay the video that the livestream uses so that audio and video are synced).

The issue is that whenever I add an effect to one of the ~20 channels, that channel (and only that channel) then becomes out of sync with the rest. So that means I can't add, for example, a reverb effect to the snare drum or some voice effect to one of the microphones without causing those channels to get out of sync with the rest of the voices/instruments, which literally ruins the mix.

So I'm wondering: is there a way to compensate for that latency, like adding the same amount of latency to the remaining channels? The best way I could think of doing it is adding all those effects to all channels and them turning them off on the channels in which they won't be used, but I guess that'll add a lot of stress on my CPU unnecessarily. There has to be a better way to compensate for those effects' latency... right?

I don't care if the final product is delayed by 1 whole second or more, since I can always delay the livestream video, as long as all channels from the mix are synced and the mix is not ruined. I'm using Audition 24.0.0.46 on a 64-bit Windows 11 running on an i7-12700H at 2.3GHz (up to 4.7GHz). Any help would be highly appreciated.

Report · Nov 08, 2023

I've got a feeling that your analysis is correct. The problem (if I've understood this correctly) is that the only way to compensate for latency introduced in one channel is to delay all of the others to compensate for it, simply because there's no way to magic away latency. Also, you're doing this to a live stream. I think that the difference this makes is that at no point in your scenario is there a mixdown, in which it's straightforward to compensate for latency - which it has to do to take account of all effects added to all channels. Or am I missing something?

Report · Nov 08, 2023

I'm sorry, I'm new to all this so I'm not familiar with all the terms. If by "mixdown" you mean actually exporting the multitrack to a final file, then you're correct, that never happens. It's all live, I don't even press the "start recording" button so there's no "post-processing" whatsover. I'll now try to apply the same effects to all channels (but turn them off for most of them) to check if it applies the same latency to all (and doesn't burn my CPU in the process). But I honestly expected to be a way to make Audition "calculate" that latency and somehow apply it to all other tracks so the mix is always in sync.

Here's the current final product btw. I'm fine with what we have so far (just some EQ and gain applied, which added no latency whatsover to any of the channels), but since we're now using the mixer's DAW this would be a nice opportunity to start producing some nicer-souding stuff by using effects/plugins. Thanks for the help!