Stereo track and AU plugin


Most of my AU plugins does not work on stereo tracks in Ardour.

I can not imagine working without a good EQ (such as Eqium by Elemental Audio, now bought up sold under a new name). When trying Ardour to load a plugin on a stereo track Ardour refuse loading the plugin and returns:
“You attempted to add a plugin (Eqium). The plugin has 1 inputs but the at the insertion point, there are 2 active signal streams.” …

Splitting an acoustical A-B or X/Y recording in to two mono tracks and doing the EQ twice is not a good option for me. The plugin needs to be identical on both channels when setting up too.

All editors I tried, capable of using AU-plugins, handles this plug-in without problems on both mono and stereo tracks. Is there anyway go get this working in Ardour? Is it a known problem?

Sorry I missed you on IRC. Bad time of day for me, often.

It would appear that this plugin probably has 1 input and 2 outputs. That means that we can’t handle the case of 2in/2out tracks by just replicating “hidden instances” of the plugin, as we would if it had 1 input and 1 output.

Lets talk more on IRC.

Paul you misred what he wrote;) It is the other way around, the plugin has a single input, but there are two active streams(Stereo track).

To the OP, in 2.8.2 IIRC there is a link in the Help menu to “Chat”. This will open up your web browser to the #ardour-osx chatroom, where you can chat with Paul(If he is around).


The track must be stereo(?). I can see that there are two graphs inside the track, twin VUmeters beside the fader and I can hear that it is stereo, the master VU-meters indicates too that it is receiving stereo information. I can not add the Eqium plugin to the master fader either.

I can add the STTool (stereo wideness/phase manipulation/meter, by flux) and any of the apple AU plugins.
But the EQ plugins (about the only plugins I use and rely on), like Eqium and Trackplug (from Wavearts) fails with the message:
“You attempted to add a plugin (Eqium). The plugin has 1 inputs but the at the insertion point, there are 2 active signal streams. …”

I will se what I can do about IRC, haven’t used it before…

You apparently don’t have stereo tracks - Ardour is telling you that the plugin would only receive a single input. It would be vastly easier to tackle this on IRC (#ardour-osx) but be patient with the timezones and people being there to assist. I’m there most of the day, US Eastern time.

AU I/O configuration is quite complex and its possible that Ardour has some issues with the way this particular plugin reports what it is capable of. I’d like to get it fixed.