Audiobus 3 as a MIDI transformer

iamspoon

Hello Bus,

I would like to route some external MIDI controllers through the new MIDI side of the App and use Audiobus 3 purely as a way to remap the incoming MIDI messages with the MIDI tools on various channels and send these back out to hardware synths.
(No audio output Apps being used.)

I'm hoping this will work at near-zero latency rather than being delayed by the audio buffer size within Audiobus.
Anyone tried this and willing to share their experiences here?
Thanks.

gonekrazy3000

@iamspoon said:
Hello Bus,

I would like to route some external MIDI controllers through the new MIDI side of the App and use Audiobus 3 purely as a way to remap the incoming MIDI messages with the MIDI tools on various channels and send these back out to hardware synths.
(No audio output Apps being used.)

I'm hoping this will work at near-zero latency rather than being delayed by the audio buffer size within Audiobus.
Anyone tried this and willing to share their experiences here?
Thanks.

it does work near zero latency on the ICA4+ atleast. substantially lower latency than just coremidi => midi ports.

iamspoon

@gonekrazy3000 Cheers, that bodes well for it working similarly with my Roland Duo-EX or Studiomux MIDI ports I imagine.

Anyone else tried this esoteric setup? : 0

wim

Why would MIDI messages be delayed by audio buffer sizes? There's no audio involved.

iamspoon

I thought the whole AB engine might be interlinked in such a way that this could be the case. Hopefully not though.

wim

It's possible. I hope not though.

iamspoon

^Likewise.

@JohannesD any idea how this would function?

iamspoon

Hello,
Further to my original post about using the MIDI mixer and plugins with external MIDI gear, I am wondering about something else related to this if anyone can help!

I'd like to know if it's possible to use multiple lanes in the MIDI mixer with each lane being fed by a separate MIDI channel coming from a single MIDI port?

In this setup each MIDI channel could be discretely processed using the MIDI tools before being output back into the external gear.

Thanks for any info.

(Still holding out on upgrading to iOS 10 and Audiobus 3 due to connection issues with Cubase IC Pro : ( )

wim

I know the input part of what you describe can be done. It's possible to have multiple lanes from the same midi controller, each processing a different channel. I tried this with apps in the output slots. I haven't tried outputting to hardware though.

Just plain 'ol MidiFlow will do that for you too, even without AudioBus, I think.

iamspoon

Yeah I have the original MIDIflow App and it can do it AFAIK but I'm mostly interested in using the new MIDIflow tools to restrict to key, randomise and other transformations per MIDI channel.

If it makes it any clearer:
I'm plugging a single port MIDI device into my iPad (Duo Capture EX, although I also have the Studiomux App), but this is itself connected to an 8 channel MIDI box with various keyboards and MIDI sound modules connected to that.

The plan I had was to use multiple lanes in AB3 on specific MIDI channels to process the input and output of all these devices independently.

From what I can tell, it seems MIDI channels are not part of the AB3 specification which would probably restrict this kind of use since my iPad only 'sees' a single MIDI device as input and output and can't restrict the input/output to specific channels.

I realise this is probably not a very common case use of AB, but it would be really useful to me if I could use it as a multi-channel MIDI transformer in this way.

Hope that makes some sort of sense!

JohannesD

I don't see why this would not work (I hope I didn't miss something). Audiobus can restrict MIDI channels for hardware inputs and outputs: Click on the (i) icon right next to the port. You can select the channel, default is omni. You can then apply some MIDI transformations with the Midiflow apps, and then send the output to a hardware device on a specific channel.

iamspoon

@JohannesD Ah that's great, thanks for your input. I'm sorry it sounds so convoluted when trying to explain : )

I did watch your videos but it was unclear if the (i) icon would reveal those settings or whether MIDI was strictly per device port rather than per channel.

I guess the remaining question is whether that is also true for the output slots too. Can they also be set per MIDI channel in the same way? (all on the same port.)

JohannesD

@iamspoon said:
I guess the remaining question is whether that is also true for the output slots too. Can they also be set per MIDI channel in the same way? (all on the same port.)

I corrected my post:

@JohannesD
You can then apply some MIDI transformations with the Midiflow apps, and then send the output to a hardware device on a specific channel.

So, yes, that is possible.

iamspoon

@JohannesD Cool, thanks very much.

If you don't mind, I'm also keen to ask about the opening post in this thread too.
Do you know whether the MIDI operations are subject to any latency due to audio system buffer size or whether the two systems operate independently?

In other words, if I only use the MIDI side of AB3 without any Audio Apps loaded will there be any noticeable delay from the MIDI functions used in the manner I described above?

Thanks for your help

JohannesD

@iamspoon said:
Do you know whether the MIDI operations are subject to any latency due to audio system buffer size or whether the two systems operate independently?

They are totally independent.

iamspoon

Super, cheers for the information.
I will leave you in peace now!