Jonatan Liljedahl


AUM is the flexible audio mixer, recorder, and connection hub for your iPad, iPhone and iPod touch.


Connect hardware inputs and outputs, Audio Unit extensions, Inter-App Audio apps, Audiobus, soundfile players, built-in signal processing and filters, in any configuration you want.

Route anything to anywhere with mix-busses, effect sends, audiobus ports, and external multi-channel audio interfaces.

Play hosted synths and instruments using the built-in keyboard or external MIDI controllers, or sequence them from other apps using Virtual MIDI.

Record mixes, individual tracks, or both, straight into the storage space of AudioShare (no copying of files needed), with synchronized start and end.

Play back recordings, soundfiles and loops as channel sources in the mixer for backing tracks, further processing or mixing.

Route MIDI in any way you like using the MIDI matrix.

Synchronize everything with the transport clock and play in time with other apps or devices using Ableton Link, a new technology that synchronizes beat, phase and tempo of Ableton Live and Link-enabled iOS apps over a wireless network. Sync old hardware to AUM via MIDI clock.

Includes built-in processing nodes for various stereo processing, Mid/Side balance and conversion, EQs and filters, limiting, clipping and saturation. Or use any 3rd party Audio Unit extension or Inter-App Audio effect.

All controls in the mixer can be controlled via MIDI, including parameters of hosted and built-in plugins.

News & Reviews


  • High quality audio up to 32-bit 96kHz
  • Clean and intuitive user interface with crisp vector graphics
  • Extremely compact and optimized code, very small app size
  • Unlimited* number of channels
  • Unlimited* number of effect slots
  • Inserts and sends are configurable pre/post-fader
  • Internal busses for mixing or effect sends
  • Supports multi-channel audio interfaces
  • Supports Audio Unit extensions, Inter-App Audio and Audiobus
  • Audiobus state saving
  • Highly accurate transport clock
  • Metronome with selectable output and optional pre-roll
  • Sends host sync to Audio Unit plugins and IAA apps
  • Send MIDI clock to external hardware
  • Play in time with Ableton Link
  • FilePlayer with sync and looping, access to all AudioShare files
  • Records straight into AudioShare storage space
  • Record synchronized beat-perfect loops
  • Built-in nodes for stereo processing, filtering and dynamics
  • Latency compensation makes everything align at the outputs
  • Separate Inter-App Audio / Audiobus output ports
  • Built-in MIDI keyboard
  • Fully MIDI controllable
  • MIDI Matrix for routing MIDI anywhere

* only limited by the CPU power of your device

Built-in Signal Processing

Stereo processing

  • Stereo balance
  • Stereo to mono
  • Stereo panning
  • Mid/Side balance
  • Mid/Side to/from Stereo convert
  • Invert phase

Filters & EQ

  • Parametric EQ
  • Low-shelf filter
  • High-shelf filter
  • Low-pass resonant filter
  • High-pass resonant filter
  • All-pass (1st order)
  • All-pass (2nd order)


  • Gain
  • Hard clip
  • Saturation
  • Lookahead peak limiter

Additionally, use any 3rd party Audio Unit extension or Inter-App audio app.

Frequently Asked Questions

It's built into the app, tap the menu button and then `Help`. There's also a copy of the manual online:

Just tap the big square '+' button!

Tap the channel title label. You can there rename the channel, remove it, as well as access MIDI control routing for this channel and its nodes.

Tap the `+` in an empty slot and choose between available nodes.

Swipe the node to the left to reveal the eject button. Tap the eject button to unload the node.

The effect slot area is scrollable, scroll to bottom and tap the `+1` button. Alternatively, just double-tap the effect slot area.

Tap the slot to show the node picker, at the end of the list is a `Remove empty slot` button.

Yes! Long-press an effect slot or node to show the pre/post toggle.

Drag an effect node to the right, and then up or down before releasing it.

Drag the channel down, for example by grabbing the output slot, and then left or right before releasing it.

They go into a folder named 'AUM Recordings' in the shared storage space of AudioShare, and can be viewed in AudioShare or by tapping the menu button and choosing FILES inside AUM.

Since AUM version 1.1, you can select hardware mono inputs and outputs directly in the node picker.

Tap the tempo in the upper left corner, then tap the three dots in the menu that shows. This will open the Clock Options, where you can enable Link, choose time signature, sync quantum and pre-roll.

Unfortunately the Ableton Link technology has no mechanism for start/stop, as can be read on their website. You need to manually start each Link enabled app, or use the global play trigger button in Audiobus (but then you need to route the apps you want to start through Audiobus).

However, AUM sends Inter-App Audio host transport state and clock sync to all hosted apps. Apps listening to this will start with AUM and sync accurately with its tempo. I recommend that you ask developers to implement this, it's really not harder than Link. See here for some developer notes on the subject:

Since version 1.2.1, AUM allows sending MIDI Clock to a single CoreMIDI destination. The purpose is to synchronize external hardware. The clock is aligned with the audio output of the device.

NOTE: Trying to use it for syncing other apps or via wireless MIDI will probably not align well! There's no reason to continue using MIDI clock for sync between apps, when we have Inter-App Audio host sync and Ableton Link.

Inter-App Audio apps and Audio Units should implement host sync, which has been part of the IAA standard from the beginning, and is the natural way for a node to sync to the host (AUM in this case).

This is an iOS 9 bug, that makes audio delayed almost a second! Fortunately there's an easy workaround: When this happens, plug in a pair of headphones in your device, then plug them out again. Latency should then go back to normal. This issue seems to be fixed in iOS 9.3 for most users.

Since AUM version 1.1, there are MIDI channel filters on IAA and AU MIDI destinations!

This is most probably the "Inter-App Audio Zombie Bug", unfortunately there's nothing AUM can do to prevent it from happening. The best way to avoid this happening is to make a habit of always swiping out music apps from the multi-task view when done with them. Also, always make sure to switch to a loaded IAA app at some point, so that it appears in the multi task view, otherwise it might still be running in the background as an invisible "zombie" process that prevents the app to load again.

You can also try the Clear RAM Trick to clear all processes, including any invisible IAA zombies: Hold power button until "slide to power off", then release it. Then hold Home button until the home screen shows up. All processes are now cleared!

For developers, I've found a way to make IAA zombies much less likely to happen. Check out

I've seen some IAA node apps that don't correctly start their audio engine when launched in the background via a host app like AUM. In those cases, it often helps to make sure "background audio" is on in the other app, and to launch it manually and let it keep running while you load it into AUM.

AUM keeps running in background when needed, unless the session is empty. Just double-tap the home button and swipe the app out of the multi-tasking view when done with the app. If you hadn't saved your session, you can tap the "Restore Session" button next time you open the app.

Where can I ask additional questions?

You can use my forum, or drop me an email!

Page last modified on October 25, 2017, at 11:09 AM π