Ah, I did not think about that yet. Using two head-trackers may or may not work, if the slightest difference occurs in the detected head-positions for the A and B part then the result would get messed up I think. Better would be if the signal from one head-tracker could be split, but I have no idea what kind of signals are going through those cables or if it would be possible to split at all. And the A8 has a totally different head-tracker, wireless I think(?), I have no clue what is possible for that either.