On Mon, Jan 28, 2013 at 10:14:48AM +0000, Dave Malham wrote: > On 28 January 2013 02:53, Ross Bencina <[email protected]> wrote: > > > > > How about deriving word clock from the AC power line? :) > > That's probably the simplest solution for something that could use > local SD card players, though not for real time work. Keep the average > sample rate over a long period of time synced to the AC frequency > (doesn't matter if there is some drift due to distribution grid > loading, as all units should see this the same) and start time > controlled by a simple RF remote control system. They'll all stay in > sync and so long as the inter-unit delays are minimal (see Fons' > earlier email) it'll be fine for pretty well anything except perhaps > wfs
Syncing to the power line would require relatively simple electronics (a simple very low BW PLL) and do the job nicely. If the sound card has software clock offset controls almost no extra HW would be required. The remove any remaining constant delay differences a simple solution would be to measure them, e.g. using a short linear sweep, and then send a correction to each unit. This could be entirely automated. Once done, all units would stay in perfect sync as long as they have power. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound
