Incoming...811b horns without vanes

[Elitopus1]

I use a single thin layer, but thinking about trying several layers, or a single thick one.

Ok thanks. Looking at my 802D and Emilar EH800 horns they both look pretty flat on the mating surface. It does make sense that I wouldn't have to use a thick cardboard gasket.

I looked in the horn throat and with the cardboard gasket you can see a big gap between the horn and driver. With a thinner gasket or none there is no gap at all.