Logic Pro X Logic randomly changing MIDI IN/OUT configuration mid-session

JamesBRey

Logician
Hi Group.


Strange problem here with my Logic X set-up. For some reason, Logic senses and changes the number of MIDI ins and outs available on my system at random unpredictable times - sometimes mid-song messing up what I'm working on.

I have the UNITOR-8 drivers and am using 4 UNITOR-8's as well as an NI interface in the AGGREGATE mode for MIDI / Audio. The NI and an Apogee Ensemble Thunderbolt are the audio interfaces.

Seems like something is happening on the MIDI bus that Logic is auto-sensing. Have used this setup for many years and have upgraded along the way - problem has been with me for some time but not sure when exactly it started.

Any ideas how to fix?

TIA!


jr (LOGIC X 10.4.4, Mac MINI i7, Mac OS 10.12.6 soon to be upgraded to 10.13)
 
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facej

Logician
Any chance you have Bluetooth MIDI enabled on some iOS device that comes near? I have had my iPhone decide it wanted to "play" and change things up a bit. My MIDI environment is much simpler than yours.
 

JamesBRey

Logician
HI. More info on this problem. I have discovered that it relates somehow to the use of my control surface - in this case a FRONTIER Tranzport.

It happened again mid-session one day and I noticed the Control Surface indicator squares left of the tracks disappeared and reappeared for no apparent reason and this is what is causing the glitch in the MIDI i/o stream during a playback / recording.

I guess I can disable the control surface as needed - but does anyone have any idea why this might be happening or a way to avoid it? I can also see that the Frontier driver is sending out a constant stream of MIDI SYSEX data so this might have something to do with it also.

Any ideas on a possible solution?

Thanks. jr
 

facej

Logician
One thing to test/check is the MIDI path. I have MIDI devices connected via USB, almost all of them going through a USB hub. At random times (infrequent, but they occur) a MIDI device will "come and go" meaning the device will disconnect and maybe reconnect.

Make sure your cables are sound. Plug USB devices directly into your Mac (if possible) and make sure that everything that is connected to the hub is behaving correctly.

I make it a point to completely power down my USB MIDI chain at least once a week. Remove power from USB hub, unplug all the devices from the hub, power down all the devices.

When I plug it all back in - power the hub, power up device, plug USB cable into the hub.
 

JamesBRey

Logician
Good points, all! Thanks facej for your input. Still looking for the direct causal link to the Control Surface but it might be the USB dongle for the Frontier as this would relate .....


jr
 
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