foam ist a good quick testmaterial, but i have a problem with the transmission of sound through the material in the mids.
because you can´t simulate both horns together,
the single simulation does not help much,
but you can see the similarity to the other DHorns,
here for a satellite.
one point is the softfibre in my construktions,
if you want to take only foam you need felt for the walls,
look the plan.