# Latency compensation in AU vs VST in Live?

**URL:** <https://forum.juce.com/t/latency-compensation-in-au-vs-vst-in-live/60482>\
**Category:** General JUCE discussion\
**Created:** [March 17, 2024, 5:07pm UTC](https://forum.juce.com/t/latency-compensation-in-au-vs-vst-in-live/60482 "2024-03-17T17:07:53Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![axelcrs](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/axelcrs/32/18132_2.png) [@axelcrs](https://forum.juce.com/u/axelcrs)\
**Post date:** [March 17, 2024, 5:07pm UTC](https://forum.juce.com/t/latency-compensation-in-au-vs-vst-in-live/60482/1 "2024-03-17T17:07:53Z")

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Hello Jucers!

I am encountering an issue that suprises me a little bit I must say ; I have a plug-in with dynamic latent compensation, that I call with the setLatencySamples() method. I am really surprised because, in Ableton Live, the plugin latency stays fixed at 0 with the VST plug-in ; AU works though, and Reaper is also correctly updated (on both Windows & Mac). It seems quite strange, am I missing some step here?

Thanks a lot!

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**Author:** ![DaveH](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/daveh/32/4924_2.png) [@DaveH](https://forum.juce.com/u/DaveH)\
**Post date:** [March 17, 2024, 6:11pm UTC](https://forum.juce.com/t/latency-compensation-in-au-vs-vst-in-live/60482/2 "2024-03-17T18:11:18Z")

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I’m wondering is it also broken for you in Ableton on Windows, not just Mac?  
I haven’t tested latency for years. I just remember Ableton used to be able to set it at any time, so as a hunch, if you put a break point on the setLatencySamples function, is it being called only once where you expect to be?  
I presume you’re only setting it in prepareToPlay()? I believe some host ignore it if it’s not.

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**Author:** ![chkn](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/chkn/32/3862_2.png) [@chkn](https://forum.juce.com/u/chkn)\
**Post date:** [March 17, 2024, 8:26pm UTC](https://forum.juce.com/t/latency-compensation-in-au-vs-vst-in-live/60482/3 "2024-03-17T20:26:23Z")

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Live has problems updating the correcting latency with VST2 under certain circumstances.

Apparently it works correct with VST3 and AudioUnits.

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**Author:** ![caustik](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/caustik/32/22449_2.png) [@caustik](https://forum.juce.com/u/caustik)\
**Post date:** [March 17, 2024, 11:58pm UTC](https://forum.juce.com/t/latency-compensation-in-au-vs-vst-in-live/60482/4 "2024-03-17T23:58:51Z")

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From your description, it isn’t clear whether your VST+AU test was on the same system. If it wasn’t, at the risk of pointing out something too obvious, Live does allow you to disable delay compensation. So worth checking whether that was switched off on the VST machine.

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**Author:** ![axelcrs](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/axelcrs/32/18132_2.png) [@axelcrs](https://forum.juce.com/u/axelcrs)\
**Post date:** [March 18, 2024, 11:57am UTC](https://forum.juce.com/t/latency-compensation-in-au-vs-vst-in-live/60482/5 "2024-03-18T11:57:15Z")

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Ok, I found the problem : Ableton Live actually does not handle prepareToPlay() the same way between AUs and VST3s. In AUs prepareToPlay() is called one at the beginning, while the same function is being can be called regularly during a lifetime with the VST3.

Thank you all!