Long-term sound installation for roman baths


    May 23 2014 | 11:45 am
    Hi everybody,
    I'm working on a long-term interactive sound installation for a museum. Basically, Max gets data from 10 sensors (I'm thinking of Eowave products) with which it triggers loops, oneshot sounds, and controls volumes, filters, and sends DMX commands. The sounds come out on 12 outputs. This is the first long-term installation I make and I wondered if you had any basic advices. I know I should go for a computer with ssd hard-drive to avoid overheating. I was also told I should avoid external libraries as much as possible for a better reliability. I was wondering if using Max over a long period (at least one year) with frequent starts/stops was fine or if it would prove unreliable. Wondering also if it would be better to have Max control external hardware audio players so it just have to handle the "maths", or if it isn't worth the cost.
    Thanks guys,
    Romain

    • May 23 2014 | 12:54 pm
      On a Mac, Lingon can be useful, but you also tune launchd by yourself.
      For most of the installations I worked on, I restarted the Mac once a week (I first made sure there was no memory leak and no huge VM swap file after a week of use).
      If your installation is in a museum, you can probably get an internet connection. It may be usefull for monitoring and distant support.
      External libraries can be fine. They can be as robust (or even more) as the cycling74 externals.
      I don't think you need external hardware to play sounds. You may want to add enough RAM to put the sounds in buffer~s rather than playing from the disk (although it shouldn't be a problem anymore with SSD).
      Don't forget that the people working in the museum may be fed up with your sounds after a while, so don't play them too loud and don't forget an easy "panic button" in case they need to turn the sound/light off for some reason (or they may simply unplug the whole system).
    • May 23 2014 | 6:21 pm
      Make it a simple as possible for the people working at the museum, with a clear and simple interface with avery few controls such as an ON/OF button, a volume control. also : - how do they turn ON and OFF the max patch or application ? is there a scheduler turning things automatically on and off a specific times of the day ? - Does the patch launch by itself when the computer is turned on ? - what happens when the patch is turned off ? think of the speakers and projectors which might be damaged if there isn't a proper shutting down routine . - What happens if there is a power blackout ? - try to monitor what goes on for at least an entire week with the patch running full time to track down bugs, crashes etc... sometimes there are some surprises...
      have fun !
    • May 26 2014 | 11:37 am
      Thank you guys for your great advices!
      The installation will be in an archeological crypt which can be accessed only during scheduled visits, so the installation won't be on during whole weeks. It has to be powered on and off at the beginning and the end of each visit. The scheduler seems to be a good solution for that. I'll leave written instructions and a clear interface for the people working there, in case they need to power off/reset/reboot.
      My main focus for the moment is the reliability of the installation, as this will be a pedagogical tool during the visit and there will be many groups of visitors interacting with it. I found on forums that Max can be surprisingly stable as long as your patch is well programmed and tested in the long run, but there can be real problems with audio drivers and sensors.
      @Patrick Delges: how do you prevent memory leaks ? Have you two ever had any experience of your patch (or the drivers) going crazy (loud noise out of the speakers for example)?
      I'll try and search other threads about reliable 12-channels audio interfaces and sensors. Come back here to share the infos I find.
      Thanks,
      Romain
    • May 27 2014 | 7:08 am
      As a Max user, the only way to avoid memory leaks is to use objects that don't leak… Run your patch during a long time and check the RAM usage evolution.
      I never had patches going crazy, but I always program security routines in Max to avoid such risks.
      A couple of years ago, an outdoor installation by Paul Panhuysen using effects on sound from microphones put in a birdcage went into a huge feedback during the night. Everybody woke up and even the police came. There was no Max patch involved, only sound effects. :-)
      RME have reliable sound cards. For sensor interfaces, I never had problems with Make Controller (but it doesn't exist anymore), nor with Arduino. If your sensors are quite distant from each other, you may prefer multiple AD converters (like arduinos) with an ethernet network rather than one centralized interface. Some sensors don't like to be connected with long cables. I'd avoid wifi as much as possible.
      Be carefull with humidity! I'd leave the whole system on day and night and would only have a big button on the patch (or even better a hardware switch polled by Max) to turn on/off the installation. In such a case, I would restart the computer automatically once a week (during the night).
      p
    • Jun 03 2014 | 11:07 am
      Thank you Patrick.
      I already did a first installation during three days in the same spot with Arduino Unos connected to Raspberry Pis. The Raspberries were connected to my laptop through a local Wifi network. I used a Digi003 audio interface. No major bugs during the 3 days but I was always around and it only lasted 3 days :)
      What's planned for the moment is Arduinos connected together via local ethernet network (using Raspberries if it's necessary but I think it isn't). I'm working on solutions to protect those from humidity. I'll still try to have a look at more "plug and play" sensors as I'm not a programer. Come back to share the infos if I find anything interesting. If not I'll go for Arduinos and hire a programer.
      Regarding the audio interface, the ones that come up more often in the threads are RME, Motu and Metric Halo interfaces. Think I'll go for the RMEs.
      Thanks again!
      Romain