I figure it'll have anywhere from 8 to 10 square feet of material to complete the horn. If you're using baltic birch ply, that would be less than 1/2 sheet and run you less than $20. If using MDF, figure about $10 of material.

If you choose to buy a set of vane, from whomever it may be, add that to the cost.

The horns should be usable with most 1" exit compression driver similar to the Eminence PDS2002 in Pi speakers. That was the big reason why I was pushing for this version of the horn because lots of guys already run 1" compressions.

gar.