Quote Originally Posted by J Henry View Post
GM,
I used 18mm ply (furniture grade - veneered both sides) & got bad resonance even with the braces as shown. I put additional 18mm layers on the 2 sides & the back & it transformed the whole speaker.
I believe it. Veneered MDF is better than most furniture grade plywood these days based on what's available around here. Still, comparing a folded horn with its much greater acoustic pressure is an 'apples/oranges' comparison to a reflex cab. In its horn gain pass-band, the LaScala is making about as much acoustic pressure as almost four 416 woofers in a sealed cab, so even if made out of the best 19 mm plywood, doubling up the panels on the last third of the horn is easier for most folks than adding the amount of bracing required to keep it from 'flapping in the breeze' like loose lips.

Is the section below it a 'djk' inspired reflex chamber?

GM