Thanks David, I may just try something without a common source as you suggest.
Following on from previous discussions, quiet soundscapes might work well. I'll
just have a play and see what happens.
--- In "Avocet" <> wrote:
> I've used two "toy" Tascams together with two pairs of stereo mics.
> Syncing the tracks is fiddly and needs more than a clap. With film
> recording a clapper board gives accuracy to the nearest frame, but if
> you want to match two sounds with a common source, you need better
> than millisecond accuracy. That's why I'm saving up for a 4-track.
> With timeode recorders, the timing accuracy is better than one frame
> per week or around one 10 parts per million. With two free-running
> affordable recorders you will get a drift which will produce flanging
> from a common sound source. If you don't have a common source, exact
> sync is not necessary anyway - just sync to a passing plane or
> whatever. :-)
> o.1 millisecond across a stereo image gives a noticeable shift in the
> image - that's 5 samples at 44.1 Ks/s. One part per million drift will
> produce that in around two minutes. Mixed, that produces a comb filter
> effect based on 1kHz.
> Point to ponder - how far away can a clapper board be before it is 1
> frame out of sync? That was one of my questions for trainees. :-)
> David Brinicombe
> North Devon, UK
> Cogito cogito ergo cogito sum - Ambrose Bierce