AU plugins not resizing, controls dropping

I’m having a problem with Apple plugins under Mixbus (Mixbus 1.4.1 on MacOS 10.6.5). Certain plugins, such as AUDelay, AUDymanicsProcessor and AUMultibandCompressor have a triangular control at the lower edge of the window marked “Details”. Clicking this control should resize the window to display more contents, but that doesn’t happen. You can tell that the contents of the windows change, but the lower section is masked off. Resizing the window doesn’t let you see it. These plugins work fine under GarageBand.

Also, I lose control of the the dot shaped handles in plugins such as AUHighShelfFilter as I’m dragging them around, which is very frustrating. I reselect, drag again, moving the dot a bit and then lose control. Again, these work fine in Garageband.

@kkalnasy: from IRC:

kkalnasy: this is caused by apple failing to document aspects of the AudioUnit specification correctly and fully
kkalnasy: in addition, the versions of the plugins that we have tested during development do not have this GUI element, so we have not tested it
kkalnasy: we don’t do development on 10.6 because its very, very hard to provide back compatibility to 10.5 and 10.4 users (there are a LOT more of them than you might think)

Thanks for your response! I understand the issue with backward compatibility and lack of proper documentation. I hope this can be addressed in a future version of Mixbus in a way that doesn’t break versions running on older versions of MacOS. By the way, Mixbus is excellent.

I find Ardour to be a wonderful program. I do hope development will move to 10.6 at some point in the future? I’ve run into the same hickups…

thanks, Eric

There are two seperate issues here not to be confused.

One is the plugins that are shipped with 10.6 that cause the issues seen. The other is the development, which can happen on 10.4 just fine, but as a result Paul can’t see and test the 10.6 plugins very easily.

I will say just compiling Ardour on 10.6 is a pain in the arse due to Mac’s hybrid approach to 32/64 bit. Much less steady development.


I’m having exactly these issues on 10.6 as well.

Are there any workarounds so that we can use the full functionality of the AU plugins in Ardour?

What is required for development in this area?

@kelleydv: i’ve done some work on it already, but without a 10.6 system to work on, i can’t make any further progress. As seablade outlined, i am not going to upgrade my system to 10.6 because it is very hard to build a back-compatible release fotr 10.4 and 10.5.

Hi Paul… I’m also having the same issue as kkalnasy… would very much appreciate it if this issue is ever resolved. I’m running Ardour 2.8.11 (built from revision 7387) on Mac OSX 10.6.7. If there’s anything I can do to help, let me know…

I’m running 2.8.12 on Lion now and still having this issue. I found a clumsy workaround though. It’s VERY clumsy, and doesn’t allow for realtime tweaking but:

  • Do as much as you can with the plugin in Ardour.
  • Save the preset.
  • Open Garage Band and create a real instrument track.
  • Add the plugin and load the preset you just saved.
  • Edit what you couldn’t before and save the preset.
  • Load again in Ardour.

I used this to adjust the attack and output gain of the AUDynamics processor - my favorite AU plugin.

Garage Band is “jack-able” so, in theory, you could hook things up so that you can listen to the result of tweaks in realtime. Something like inserting the GB track in your signal chain where the AU should be… That’s a lot of work for inflexible payoff though. And I’m not sure if it would even work as expected with levels and stuff. I haven’t tried yet.

As I’ve mentioned previously, Apple changed the behaviour their own plugins in either Snow Leopard or Lion. The issues you report do not apply to plugins from third parties AFAIK. Until we get a Snow Leopard and/or Lion system setup to do building/testing on, it will not be possible to make any progress on this. I am doing some work on getting an SL system setup for building, but there are a lot of other important issues right now too.