What Do YOU Think?

Look at this stack in the picture attatched, idesigned it using Google Sketchup and all cabs there are from actual plans, but 1 thing...

above the scoops there are the hd15's from Rog Mogale's speaker plans: www.speakerplans.com/index.php?id=hd15horn do you think they could be could enough to run from 60 - 200 Hz?

if not please could you suggest plans (horn only) that will be good for the chosen frequency range

thanks