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 StoreAudiobus is the app that makes the rest of your setup better.
##Solved## Setup : 4 iPads pro connected and in sync...
Hello,
It seems quite stable, so I share my solution here
Now I need to push a bit with more synths...
Known bugs : novation Launchpad can't be connected on the USB port of ICA4+, so it's connected using an other USB hub on the third iPad. Also, with Launchpad app, you can't stop with Audiobus all loops...well...One day, maybe....
Also note that on the main iPad (used as a mixtable) I couldn't use Audiobus because of the latency too high (128 min) , so using AUM with 64.
I can record live with loopy on this Ipad, play the guitar without lag, and other output audio sources seems ok...
I would love to have a master play to play Link on all iPad at the same time...
Enjoy 
Comments
Wow, I would just be happy to HAVE 3 iPads pro
I am
(but they're "only" 32 Gb versions...)
I sold (almost) all my hardware synths to achieve that...Theoretically it should work...Even if hardware still more stable, it's really easier without all those jacks everywhere...Hope it get more stable, that's why 3 iPads allows to have less synths on each of them...
Also, children are happy to play with them while traveling
Ok, for my records
Even with more than 15 apps with Link activated all is stable BUT now that have been deeper into midi with Modstep, I've seen that even with the lowest possible latency, midi was lagging a bit...
~~So at the moment I use Midi Link sync app
https://itunes.apple.com/us/app/midi-link-sync/id1071048493?mt=8
, and add 50 ms to midi to really be in sync...~~
Then I use Midi flow and create a pipe from Midi Link Sync OUT, to all my hardware external gears, and also other ipads that receive midi (for playing additional synths, or for Ruismaker !!!! If not, the beats generated would not be in sync !! )
Problem with this app, you can't assign the start/stop to an external midi controller, wich is very annoying as everything else (the 2 other ipads) are controlled by them...
I send a mail to the dev...Let's see what happen...
~~I also tested the "Link to midi" app
https://alexandernaut.com/linktomidi/~~
I really love apps from Alexander, but my tests shows, at the moment, that it was really less stable...
Can anyone confirm that ? It might be me...
Enjoy
Eureka...I'm so dumb...
I wanted to make all iPads mixed in one place (into a kind of mixtable iPad) but it will always lead to latency...even with a buffer of 32...
I wanted to do this to record on the fly the other synths from the other ipads into one, and then finalise all loops into a final track.
But if you do a direct monitoring with the ICA4+ of all iPads, with AUM on each of them, you'll get the same result, without any latency at all...This is physical...
Ok, you can't record each individual track from any iPad just on one, so you'll get loops on each iPad, but who cares...finally...Each iPad is a multitrack recorder, then you reorganize things into one track.
So I "keep it simple" for the config of ICA4+, just direct monitoring almost everywhere, I just add line 1 & 2 for my mic and guitar into the first iPad, I can sample on the fly, add effects and record them, line 3 & 4 for the third iPad goes in direct monitoring, and the second ipad thru the 2nd usb port, in direct monitoring....And REALLY voilà !
Anyway, don't know if anyone care, seems obvious when you write it down, but it wasn't for me...
Happy...Let's go to bed now...:)
lol, sick setup bro
Ok, total of 32 apps running.
Around 25% CPU load on each iPad pro.
After 6 hours, with stops and goes, some few glitches sometimes while I switch between apps, and little slow on the tempo, (glitch tempos ?) but not very big (but noticeable)
Midi controllers doesn't crash either.
On a slow track it's okay, but when I'm afraid with heavy playing...Keep testing...
Well, first live track with this new setup...Still some bugs...But it' slowly getting better, but still very dangerous in a live situation...
Ok, I think I might found the problem...
On the ICA4+ to avoid much as possible glitches I've setuped in audio parameters
Number of buffered audio frames : 5
Sync factor value: 4
I was focusing of getting the best latency possible, but with my live config it seems not relevant...
What they say about that:
http://www.iconnectivity.com/blog/controlling-latency
Number of Buffered Audio Frames - refers to how many USB frames of audio the interface will buffer between the two USB ports. Each frame is 1 millisecond of data. Lower values yield lower latency but at the risk of distorted sound (lost data). Higher values yield higher latency but less likelihood of distorted sound due to lost data. User should select the lowest value that works best for their system.
Sync factor Value - used to calculate the frame rate for synchronization between the two USB ports. Lower values yield higher jitter, high values yield lower jitter. User should select the value that works best for their system.
So IMO I can accept a bit more of latency, hopefully not so much noticeable (AUM : 256, with latency compensation on ) to allow the best constant signal, and on the other hand reduce the jitter to the max, as it is for live performance...
I'll see now if I have less artefacts...
I also tested 24 bits 96khz to lower the latency but it directly double the CPU load on the iPad, AND I directly get scratch with the audio analog input of the soundcard, so it's defenetly a no go (in my situation...)
thanks for the background info and best of luck
@Telefunky you're welcome
Ok, so finally, all seems stable...Last point I had to think is that on the 3rd iPad I'm using a QX1222 USB that must be in 48 khz, if not, I got sometimes glitches (seems it came also from that...)
All iPads are used between 28 & 35 % (CPU from AUM) and 1.9 & 2.2 GB use of RAM.
I may now work on new tracks and chaining. (but first...HOLIDAYS for 2 weeks
)
I also add my iPhone 5 in the set as a Link's metronome (using Launchpad, very nice metronome
) and a TC-11 for some weird sounds...
)
I've been really disappointed by some apps, and some others where finally a very good surprise and fit perfectly ! (Launchpad is really cool finally, yes !
Good stuff. Thanks for sharing all of the details. Dug the longer track a lot.
Impressive sound check
I really like the main synth pad, at first I thought you were going to launch into a Stranger Things cover 
Maybe you've already figured out the 5:17 glitch. To me it sounds like what I would get when iOS takes over with some background task (like email push or some other background notification when an app is refreshing data online). Almost like iOS takes a second to temporarily do what it wants and ignoring the fact that you have a dozen music apps that need to stay on priority.
@syrupcore @Htmx thanks for the nice comments
I will check all notifications from all apps...I've already disable Links notifications, and been careful with what others apps can send, but I must have forgotten some, so it's a very good reminder...
I also disabled bluetooth, transparencies, and transitions effects.
Hello there,
Here's a new track done with this setup. I've added a Quneo, and it's a really cool controller...
You can't see it in action as the camera has to be put somewhere else...Need to fix that detail for the next video...
If you need someday better sync and want to externalize it I recommend look into bomebox. Maybe it will give some extra stability plus midiflow plus OSC plus midi din and ethernet... but maybe you have all covered by iconnectivity hardware. Just dreaming without limit since 3 iPad pro are over my budget for few lifes... xD
Jesus Christ!!!!
I'm lucky to have managed to build a pretty wicked live setup between my Air2 and Mini2, but DAMN.. As a full time freelance musician this just makes me feel bad. Three iPad Pro's!!.. Are you fucking kidding me??! I make most of my wages from an old beat up double bass that I got from a school's music department auctioning off it's old junk!!
Wicked setup though. Once I started to get over the fact that I'm most likely never even going to own a single iPad Pro, then I started to bask in the coolness of it. Post more videos with explanation of config/workflow etc.!
@Dubbylabby thanks, didn't know the Bomebox ! Nice device ! But it's true also that I can handle with Midiflow, and Apollo for all my needs at the moment...
The Iconnectivity Audio 4+ is also a big help to achieve this...(2/3 of the price of the Bomebox, so...)
@OscarSouth yes, 3 ipads sounds a bit greedy, but if you consider a real pro synth, let's say an Analog Four, second hand, it's the price of an iPad pro...And you've got a 6 voices analog synth, multitimbral 4 parts, with a unique sound, true, but THAT is very expensive omo...
But its true, I have to buy apps, sound card, midi controllers...But I can run 3 Model 15, 3 DRC, 3 Animoog, 3 or more Troublemaker, at the same time, with effects, like Sugar bytes...All that could go on stage in a big suitcase, and that's it.
All is connected to AUM, so I can record "direct to disk", in multitrack, edit in Cubasis, export, then done...
If I like a track live, I can prepare the Cubasis edit version right away.
I have so few wires now as I had 20 years from now...And so much power in my configurations now...
So much headaches also with all the virtual midi routing, and glitches from nowhere, crash from apps (even with Audiobus, at the moment I even stopped using it...) bad midi implementation (no Program Change, no midi channel that you can change, bla bla bla...) but also the doubts to have made the wrong choice by not buying proper synths, doubts with some midi controllers that are CRAP ( you can do this, but not that, or this but just in a particular case) I even had doubts for a good wifi local router, doubts on good quality usb hub...
On the other hand, I also get IAA sync, Link sync, if I want a new synth : 10 box, and I don't need to move in a bigger place, buy some more cables, adaptors, bla bla bla...
The workflow has been really a pain in the ass for long, now it's getting a lot easier.
I hope IOS 11 will be THE IOS that will bring the perfect stability I need, and some advanced version of AUM to prepare a full live for an hour or two of music, without a glitch...
I'm also considering a 4th iPad pro...lol, not sure, but I think if I get a better musicality and real needs, I might go for that !
Stay tuned for the next episode
Don't forget bomebox is also wifi router hotspot!
@Dubbylabby I think I'm gonna wait before getting any new box for a while...
Anyway, finally, I got a 4th iPad pro...
Just found a bug in Midiflow, it's going to be corrected soon...
Just finished ALL the midi mapping of the Quneo, the BCR2000, all midi connections are running smoothly between the 4 ipad, almost no glitch...
Some useful infos:
1.Latency 256 on all iPads.
2.Keep at ALL time at least 1gb of free memory, around 700/900Mb you may get pocs already...
3.Never goes up to 50% of use (number taken from AUM), using around 35% is already a lot...
4.If an app slows everything, or generate instability, too bad, even if it's a cool app, don't use it.
5.It takes AGES to set a midi controller, not to assign, but to get something really ergonomic. Keep it simple...Save your midi channels, your mapping must be super hyper duper organized. If not, you'll get midi conflicts, that's absolutely sure.
A little organic loop created to finish the mapping/effects/soundcheck, probably for my next track:
Congrats on that setup. New video coming?
Not yet, now it's time for really composing. I've been using the same drum patterns for 6 months now !!!
I also need to finalise my "master ergonomic massive patches control of program change" between tracks...
I guess my next video would be 2 or 3 tracks, a mini live...
Also need to check the voice patches...Design the Modstep's matrix. Damn, still stuffs to do...
Ok, just to explain a bit more how all this works, I made this video, hope you'll like it:
@crony your setup explains the constant urging for all apps to have MIDI PC.
@InfoCheck true, but even with just one iPad, for a live there's nothing faster and efficient than program change...