The one magnet is enough. Just mount the sensors so that they can read it and there are a lot of pictures in this thread.

On a side note I will be planning on attending the Toledo show and hope to have several new products there (in the RCS booth). Not definite yet but that is my plan. I hope to meet many of the guys that have contributed to the development of the twinsync there. Besides the Twinsync I hope to have some really cool new things there.

BillW