Vax

Unfortunately, I will not be able to borrow any of the materials as they will be destroyed in a fiery blaze at the end of the (art) event. I have access to high-precision surveying equipment, so precision will not be a problem. I was thinking along the lines of spraying foam and carving it into 2 different forms for setting/curing the panels, to be used 12 times each per parabolic dish. The material to build the panels with is still a big mystery to me. Ideally it will be sturdy and dense enough. I am looking for an adhesive solution that burns relatively cleanly. I have budgeted $5,000 US for materials. Fortunately all labor required will be covered voluntarily.

(image not to scale) I'm interested in creating a pair of 15 meter diameter parabolic dishes facing each-other at an outdoor event taking place on a dry lake bed with a set of stairs leading up to a platform that would allow a group of people to talk or sing in the focal point, allowing long-range transmission of audio between the two points over a relatively large range, preferably more than 200 meters. First off, is this even feasible at this distance? Will there be too much noise pollution or loss of voice quality or amplitude? The temporary structure will need to be assembled on-site. I believe sectional panels could be cheaply built using cloth, chicken wire, and adhesive laid on a form. Will these panels suffice acoustically? Is density of the material a big factor here? Thanks for any help -Vax