This is going to sound dumb... but why would sound stop?

    Apr 01 2012 | 7:36 am
    I know that forums can be full of people posting odd problems that are vague and non-descript, so I'll try and be specific! But this is odd...
    I've been working on a large patch for quite sometime. And its been working fine.
    All of a sudden, my audio won't come out of my dac~, or possibly my soundcard. Its a little hard to tell.
    I have a dac~ with 6 outputs, and routing a variety of audio in. I've connected meter~ objects to all of the recieve~objects that channel into the dac~, and they illuminate, just like audio is flowing.
    My soundcard, a motu ultralite mk3 is signalling on the front that audio is flowing into it. But nothing comes out the headphone jack, or through my mixer.
    Here's the weird part. I open up the help file from groove~. Test it and it works. Everything lights up as you would expect, but I actually hear audio. No difference in operation apart from the fact that I hear sound in this one. Where as my patch makes no sound anymore.
    I've also tried selecting the internal soundcard on the macbook pro and running the same test. The same thing happens. My patch won't run, the groove~ help file will. This makes me think its not my soundcard but something in Max/msp or my laptop.
    The odd thing about this is that the patch was working. I mean, routing audio isn't by any means the trickiest thing to do in max. And I've been using this set up for awhile.
    As to why it would just stop, I have no idea. It did manage to come back to life after two hours of cursing last week (its just spontaneously decided to do so), but I've come into my studio fresh and the same problem is happening.
    If anyone could help with suggestions or tests I could try that would be great.
    Thoroughly confused, Todd AK
    Running Max 6 on a Macbook Pro, 10.6.8 (snow leopard), 2.5ghz intel core duo, 2GB 667MHz DDR2 SDRAM, with about 13GB of free hard drive space.

    • Apr 01 2012 | 10:19 am
      Could be a blown filter or DC-Offset problem. You can hook up a [scope~] before your [dac~] and see if the waveform looks ok.
    • Apr 10 2012 | 8:13 am
      Mudang: I hooked up a scope, and I see nothing, it flatlines.
      What's a blown filter involve? Or better, how is it rectified?
    • Apr 10 2012 | 8:46 am
      rectifying blown filter: only applicable if you're using something like biquad~, use the 'clear' message to reset the filter.
      it's confusing if you have meter~ show something but scope~ is flatlining. but when this has happened to me before, it's usually because i've created a signal feedback loop:
    • Apr 13 2012 | 5:28 am
      Raja: Thanks for the example! And the advice.
      It seems a clear message did it, but I had a 'cascade~' object that was blocking the works. Thanks all!
    • Apr 14 2012 | 8:24 pm
      ya, i had the same problem before toddak, drove me nuts until i followed the chain down to the filter and realized it was the problem. keyword was followed it DOWN, if something isnt working right like that, i usually find a part of the patch thats outputting data properly and then follow it down until i notice a problem. then you know what object is causing it.