Audio Unit: parameter automation advice

Hey guys,

I’m developing a drum synthesizer audio unit, and it’s running like a dream with Cubasis.
However, parameter automation is still something that no AU host on iOS (including Cubasis) fully covers, hence I currently also support MIDI CC messages for every parameter.

This sort of works, in the sense that Cubasis records and plays back the CC messages but they can not be edited after being recorded. At the current state of AU support on iOS this is as good as it gets, I guess.

My question is: do you see any practical/technical issues with this solution; supporting CC and AU Parameters for controlling the synth? Or can there be situations where this potentially conflicts?


More info

do the CC messages show up visually in the interface once recorded?

Also will your AU support loading drum samples?

In Cubase they are currently not visible, unless I’ve overlooked a setting somewhere. But as I said, it’s all up to the host applications to support parameter automation, so this is the best I can do as an AU to support automation within the current limitations.

My AU is fully synthesized in realtime, so no samples involved. You can read more about the project >here<

Supercool, I look forward to downloading it when it’s on the App Store

Hi brambos,

As of yet automation for AU instruments/effects is not supported.


Thanks for chiming in, Lars.

I’m aware parameter automation is not supported. But recording of MIDI CC messages works, which is what I’m implementing in my drum synth right now. I was just wondering whether that would lead to possible conflicting behavior right now (or possibly further down the line) in the way Cubasis handles parameters in iOS Audio Units.


Hi brambos,

From our engineering:
How exactly do you record MIDI CCs from your AU plugin with Cubasis? Is the CC data written to a MIDI event in the arranger? We cannot test it since we don’t know of any other AU instrument that does that.
In general, Cubasis sends MIDI CCs that are contained in a MIDI event to the AU instrument plugin that is assigned to the MIDI track. The MIDI CC data can be edited in the MIDI editor: Double tap the event on the track to open the editor, then tap “Velocity” in the lower left corner to open the parameter (CC) list.


Hi Lars, thanks for checking!

Currently my AU does not send CC, but only receives CC. Internally, my synth engine is fully controlled through MIDI CC messages and all AU Parameters it receives are first translated into MIDI CC. Hence if the user controls my AU using a MIDI controller, or by programming CC messages in Cubase full parameter automation is possible.

I’ll check if it’s possible for my plugin to also send CC messages when the user tweaks its UI. That would essentially work around the current limitation of AU Parameter automation. Huzzah!

I guess Audio Units on iOS are still a bit of an uncharted territory :slight_smile:

Full automation with Audio Unit plugins. Cubasis is the first host to do it on iOS (at least with this plugin)! :smiley:

Super excited about this one

Great news brambos!