I'm a fairly old school builder as well. The design of this wheel is based on rear wheels from DT Swiss (RR 1450) and American Classic (420's). Both of these manufacturers build rear wheels using 2x lacing and similar spoke gauges. In fact, this wheelset is sort of a blend between the 2 manufacturers designs.
I'm wondering if the spoke tension on the wheel is low. Like I said, its 120kgf right now. Barnetts suggests that the noise can be caused by low spoke tension, but anything over 120 seems awfully high to me.