Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.Download on the App Store
Audiobus is the app that makes the rest of your setup better.
AUFX Push side-chain gated compression effect tutorial
This is a random AUM keyboard playing the tutorial sound. I will begin to write and show you how to achieve it with only compression limiting technique. Ya, I know the tune sucks , no worry it will be a great tutorial. This tutorial is difficult for me to write, but once you understand it, it is one of the best thing you can have musically.