View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0010418 | ardour | bugs | public | 2026-06-25 22:21 | 2026-06-25 22:21 |
| Reporter | GhostsonAcid | Assigned To | |||
| Priority | normal | Severity | minor | Reproducibility | always |
| Status | new | Resolution | open | ||
| Platform | macOS | OS | Mojave | OS Version | 10.14.6 |
| Product Version | 9.7 | ||||
| Summary | 0010418: RJ Studios AU plugin is given an incorrect plugin latency compensation after a restart | ||||
| Description | Heyyyo, Not sure if whatever's causing this affects *other* Audio Unit plugins in Ardour/Mixbus, but within a *44.1kHz sample-rate session*, the AU version (-ONLY the AU version-) of RJ Studios' "True Mid/Side" plugin switches from a correct =92.88ms latency compensation to an *incorrect* =85.33ms *after a restart* of Ardour/Mixbus (-see picture). This leads to inaccurate PDC and phase issues, etc.. I assumed this was purely the plugin's fault (-again, the AU version), so I emailed RJ Studios earlier today, and Jeff Rippe has already replied back, stating the following (which I think you might find interesting): "The code used applies to all versions of the plugin. So if VST3 works but AU does not then I'm afraid it is an issue in Ardour. Harrison Mix Bus and Ardour are not widely used DAWs (compared to Reaper, Logic Pro, etc.) and are not typically part of our test base. That said, we have had some peculiar issues with Ardour - reported them - and received no reply. What you have reported honestly makes no sense UNLESS Ardour is reporting the wrong sample rate to the plugin. 92mS is the latency at 44.1kHZ and 85mS at 48kHz. There is no other reason why the latency would be off by that exact amount." ... Jeff seems 100% correct about the 44.1 vs 48kHz difference, as the math clearly indicates: 44,100 / 48,000 = 0.91875 0.91875 * 92.88ms = 85.3335ms So anyway, I do wonder... Is this in fact an issue with Ardour/Mixbus in their handling of AU plugins? All in all, I *might* just settle and use the VST3 version which does NOT suffer from this issue, but I don't necessarily like the rigidity of the I/O (i.e. the AU version has */* for the Audio I/O, whereas the VST3 has a set 2/6). Thank you very much for reading!!! : ) -J | ||||
| Steps To Reproduce | 1. Get on a macOS machine/VM(?). 2. Download the "True Mid/Side" plugin demo from: https://www.raisingjakestudios.com/utility%20and%20fx.html#xl_True:32Mid:47Side 3. Install the AU and VST3 versions accordingly. 4. Create a new session *at a 44.1kHz sample-rate*. 5. Create a stereo track, and add the *AU* version of True Mid/Side plugin to it. 6. Observe the 92.88ms latency time, which is correct. 7. Quit and reload the session. 8. Observe the now incorrect 85.33ms latency time. | ||||
| Additional Information | In a nutshell, it's as though when Ardour/Mixbus goes to apply a latency time to the AU version, it thinks or simply *defaults* to an *assumed* 48kHz-relevant time (i.e. 85.33ms), instead of respecting the actual 44.1kHz sample-rate of the session. | ||||
| Tags | AU, Audio Unit, PDC, plugin, RJ Studios, True Mid/Side | ||||
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2026-06-25 22:21 | GhostsonAcid | New Issue | |
| 2026-06-25 22:21 | GhostsonAcid | Tag Attached: AU | |
| 2026-06-25 22:21 | GhostsonAcid | Tag Attached: Audio Unit | |
| 2026-06-25 22:21 | GhostsonAcid | Tag Attached: PDC | |
| 2026-06-25 22:21 | GhostsonAcid | Tag Attached: plugin | |
| 2026-06-25 22:21 | GhostsonAcid | Tag Attached: RJ Studios | |
| 2026-06-25 22:21 | GhostsonAcid | Tag Attached: True Mid/Side | |
| 2026-06-25 22:21 | GhostsonAcid | File Added: Ardour 9,7 - 'True Mid Side' AU Plugin Delay Compensation Incorrectly Changes after Restart (1).png |
