A picture is worth 1024 words
I discussed the idea of a time-alignment scheme in the article Delays, Delays, Delays. The idea is that signals which have a mechanical delay of some kind (gas transport time, for example) can be time-aligned with signals that have a lesser or no such delay by means of a “logical” delay line inserted into all channels. If the sum of all channel’s physical + logical delays is a constant, then the final output is time-aligned.
Here is a test of that concept, where three signals are generated, with different phases, and then fed thru that process. The outputs, as you can see, have been aligned.
You have to know the physical delay time, however; it does not guess. You also have to account for the fact that some data is lost at the beginning, if that’s of concern, then start your recording early enough to account for that.
Even with those caveats, this scheme allows you to shift signals to account for mechanical delays, EVEN IN REAL TIME, if you need to.