Seid geraumer Zeit schlage ich mich (auf nem IPad Air 1 & 2) mit Cubasis rum.
Ständige Knarrzzer (bei InterApp und Interne Sounds), Timingprobleme und Hänger verderben mir die Freude, an diesem sonst sehr durchdachten Programm.
Deinstalliert hab ich auch schon öfter, Mic in Einstellungen ausgestellt, Latenz geht nicht zu verstellen (256), …
In order to support you, it would be important to have more details about your project setup (number/details on instruments in use etc.).
The number of instrument apps assigned via IAA can have massive impact on the overall performance.
There are also limitations of Inter-app audio as described in the In-app help chapter “Accessories/Routing”.
It might make sense to give the iPad a full restart (power off and restart).
As stated above, please get back to us with more details.