New LV2 plugins coming from Harrison


I am a developer and product manager for Harrison Consoles. We are launching a series of new LV2 plugins for our workstation, Mixbus. These plugins have rich graphical interfaces.

One of the major benefits of using the LV2 format, besides being open source and freely licensable, is that it can work cross-platform. We are loading the LV2 plugins in our OSX, Windows, and Linux versions of Mixbus. I’m looking for an Audacity developer to help me make sure these plugins (and their GUIs) can load into all versions of Audacity. I can share the needed host code from Ardour/Mixbus if that helps. Perhaps it’s already possible; I haven’t built the latest Audacity to check if the needed extensions are in place.

If anyone volunteers to test the plugins on Audacity, I can probably provide free licenses of the existing and upcoming plugins. PM me here, and I’ll share my email details with you.

Ben Loftis
Harrison Consoles

Hi Ben,
That’s a coincidence, I was just telling someone about Mixbus today.

As this forum is at the user end of things it is quite rare that the developers come to visit. You may be better to post direct to the developers mailing list which you can find here:

Unfortunately LV2 support is currently disabled in Audacity as there are some unresolved problems, but this will hopefully be only a temporary affair and LV2 support will return in the not too distant future. I know that there is substantial demand for LV2 support, so it currently gone but not forgotten.

Hi Ben,

I’m not a developer either but I can give you some extra information in so far as the main stumbling block was on Windows - the slv2 library is written in C99 which is not supported in Visual Studio, so to get LV2 support on Windows we need to do a lot of work translating calls into C++.

If it is of interest you can see a summary of the LV2 work that was done here: .

Also I see on your site “Mixbus loads VST plugins on Windows, AudioUnit plugins on OSX, and LV2 plugins on Linux” (though I understand Ardour supports LV2 on Mac). So is making LV2 work cross-platform still in the development stage for you also?


Hi Gale,

I think I have good news on that front! SLV2 has been superseded by LILV ( We use LILV in Ardour/Mixbus and it compiles easily on Windows. The Redland requirement has also been removed; LILV does its own file parsing.

And yes, I’ll need to update our website for the upcoming 2.2 release. We will load LV2s on Windows, OSX, and Linux. The release of 2.2 will have 3 LV2 plugins bundled into the Mixbus package. Having the same plugins available on all three platforms is a goal that we’ve had for a while. I imagine that Audacity would benefit from that as well!


That sounds encouraging, especially if we can get rich interfaces going. The interfaces of our LADSPA plug-ins are only tabular.

Can you say briefly what those three plug-ins are? I’m not sure how well LV2 supports real-time effects but Audacity does not support real time effects yet.



Our announcement has been delayed by a few days, but I’ll be sure to post here when they are available!

The plugins are well-suited to realtime, bpm-aware, and automated effects, but they should still be usable in Audiacity as well.


LV2 support is now available in 2.0.6-alpha and will be released in the next 2.0.6 version of Audacity if it passes testing.

If you use LV2 plug-ins, please test 2.0.6-alpha and report any problems in this thread.

Latest pre-compiled builds of 2.0.6-alpha are available for