Are there any experiences about the possible speed for MIDI between Max and Logic? I will use a dedicated port for that but this is an application for the stage. Musicians can and will operate a pitch wheel or volume pedal and play wind controllers (continuous breath messages) while Max switches the presets.

Did anyone see that Logic swallows messages that came from Max at high speed while other devices also send MIDI? I want to be fast but I can accept very small delays if necessary. The crux is that the whole stage sound can get messed up if I lose just a single message.

Hi Peter. You already have an example – the controller < --> LC Xmu < --> Logic MIDI streams can be extremely dense.

You can expect a bit more latency than using Logic alone, and latency/jitter may increase with load, but in general everything gets through. Tip: don’t use the IAC bus (but you knew that, eh?)

I was blind. It sits always in front of me :-)

> You can expect a bit more latency than using Logic alone, and latency/jitter may increase with load,

More overall latency only while Max is very busy, right?
And what means “jitter” in this case?

> but in general everything gets through. Tip: don’t use the IAC bus (but you knew that, eh?)

Everything through is what I need. Regarding the IAC bus, I didn’t have problems with it yet but no, I don’t want this “automatic echo”. I will open a couple of ports in Max.

Timing inaccuracy.

If a port goes away, you may find Logic forgets its assignments and starts sending something to the IAC bus instead, which it also receives from. Disaster.

How do you create your own virtual ports that aren’t using the IAC bus? If I go to Audio MIDI Setup -> IAC driver and add a virtual port, it’s named “IAC Bus 1″. That’s the only way I see to create virtual ports. A while back, I think someone on this forum said the “from Max/MSP” ports were the same kind of virtual ports using the IAC Bus too, but maybe they were wrong? I tried recording into Logic with both “from Max/MSP” and the virtual “IAC Bus 1″ and didn’t see any difference.

The two automatically created Max ports do not use the IAC bus. Same is true for MidiPipe, where you can create as many ports as you want. For additional IAC ports you have to go to the Mac’s Audio/Midi Setup.

By creating your own ports in Max you
1) avoid the IAC bus
2) can have independent in- and out ports
3) can name the ports as you like

Oh, I see. This way you create definitely a port in the IAC driver.

The port creation in Max is properly hidden, for whatever reason:
Go to the documentation and search for “Using Max with Other Applications”. Click on the only link “max_and_other_apps”, on the page scroll fully down. There is the description.

I had no clue what to write as . This is not explained and my own name did not work although I have a drivers license. I just tried CoreMidi and was lucky.

But you can name them differently in Audio Midi setup…

–
Stefan Tiedje————x——-
–_____———–|————–
–(_|_ —-|—–|—–()——-
– _|_)—-|—–()————–
———-()——–www.ccmix.com

Sure, but I was pointing out that these are IAC Bus ports because the default name indicates they are. I assume naming them differently doesn’t change that.

I guess the “from Max/MSP” ports and MidiPipe use lower-level Core MIDI and bypass this IAC Bus thing, but I don’t understand what makes the IAC Bus different from these other virtual port options. I just know some people here had bad problems with the IAC Bus and suggest avoiding it.

The IAC bus is implemented as a driver, which is why it appears in AudioMIDI setup. Unlike anything else in CoreMIDI, it’s a source and a destination in each bus, which is where the feedback issues arise.

I think the IAC bus was implemented by Doug Wyatt as a lowest-common-denominator thing to help developers port their OS9 apps to OSX, so unfortunately it mimics the OS9 IAC driver as closely as possible.

But OSX is rather sexier than that for MIDI. Virtual CoreMIDI sources/destinations may be created and destroyed on the fly by any app, are always single-ended, don’t appear as a driver to the system, and don’t appear in AudioMIDI Setup (though AudioMIDI Setup does have the ability to find them when queried at the API level).