Urgent Help Please: MOTU Audio Interface Dropout with Looped Movies



  • Dear All,

    I am stumped by a multi-channel audio problem that a user is having. If anyone has had a similar experience, I'd like to know more.
    Mac Pro + 10.8 + SSD drive. Three photo-jpeg movies playing, routed to three separate projectors. The 'snd out' parameter on the Movie Player is set to 'e1-2' for the first movie, 'e3-4' for the second, and 'e5-6' for the third. This sends the stereo audio for each movie to channels 1+2, 3+4, 5+6 of the MOTU Traveller FireWire audio interface.
    This all works fine for some time. But this is an installation that runs all day. At some point, the audio for one of the movies will drop out for 10-30 seconds. It will eventually come back, but it will happen again at irregular intervals. Very random, and very annoying for the user of course.
    I went to the site personally and did everything I could think of -- including something as radical as routing the audio out to Sound Flower, and then back to the MOTU using the Core Audio actors. I did this because I was concerned that it was something to do with the audio clock on the MOTU. (I tried various settings of that as well.)
    I ensured they had the latest MOTU audio drivers, etc. I really tried everything I could think of.
    The fact that it is intermittent -- and seemingly based on how long the movie is playing -- seems to point to a problem outside of Isadora. Isadora does not "touch" the movie in any way once it's playing. Just before playback begins, it simply configures all the parameters and says "start playing now." It is not updating any of the movie settings during playback, unless you change a parameter on the actor itself.
    If anyone knows _anything_ about this, please post here. 
    Thanks a lot,
    Mark


  • Hello,

    I don't know very well audio systems and routing but a friend had recently a similar experience with this MOTU audio interface (it was the mk3 model) : there were irregular cuts (more like "clic") in Live Ableton.
    He found the solution in the clockwork between the MOTU interface and the mixing console, and using a single optical link.
    I don't know if the person uses a mixing console, but the spdif / optical connection, and the master or slave setting on the interface might be a solution.
    Best wishes.
    Clement


  • I have used MOTU gear for a very long time, and this sounds like a defective unit. That said, if it is a clocking issue, performance of the Traveller and other interfaces is sometimes improved by having an external clock source, preferably a Word Clock.



  • Dear All,

    Just a "post-mortem" on this problem. As it turns out, the problem was not Isadora related at all.
    Apparently, the speakers used for this installation -- which have integrated amplifiers, would turn themselves off if there was a period of silence, or very low volume, that lasted longer than a certain period of time. A very strange and annoying "feature" to be sure.
    Anyway, for those of you who tried to help me, thank you very much for the effort.
    Best Wishes,
    Mark


  • Hi

    Just a light weight share - in several of my installation pieces I used some vintage 1995 AR powered speakers (still have 'um and work great) that had that power-off feature. I figured out how to snip a resistor on the power board and now they don't... pretty simple.
    John

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