I thought I'd chip in here, even though I'm certainly no expert (!), but I'm not nearly as pessimistic as Justin... I'd think it should be easy to get sub-millisecond sync on a local wifi net using standard NTP. The ntp site talks about a typical 100 microsec uncertainty in such a situation. Further, if you have two 'clients' with parallel routes to their NTP master (as would be the case on a local wifi) their various delays should be similar, so their agreement would probably be even closer, even if they both had some offset from the master. The Raspbian on my Pi has full NTP installed by default, so presumably one could set up one's own timing network between several of them. And I guess one could get a good check of their actual sync by cross connecting GPIO pins and comparing time stamps on pulses between them.. My thoughts, anyway. -- Pete -- On Fri, Apr 24, 2015 at 01:40:01PM +0200, Anders Genell wrote: > > I have a sonos system at home with two small speakers and a sub in a 2.1 setup. Each speaker is an independent wireless audio player in its own right, but in the controller software they can be grouped together as a whole. In order to have functioning stereo the stream in each speaker must be closely synced to the other. I wonder how they might achieve that. > > Or, more importantly, how can it be achieved using e.g. two raspberry pi? > > My current interest is to make a multi channel sound recording system where each channel (or two channels) are wirelessly synced to all others so that a multichannel file can be created after finished recording session. > > I was thinking that it e.g. should be possible to sync the beginning of a buffer to a certain time stamp, or something... ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ Csound-devel mailing list Csound-devel@lists.sourceforge.net