1803B horn plans available?

[Audiomind]

I think the fringes of frequency response must be built in. For example, my 811 horns are rated to 800Hz, yet they're utilized in sytems with 800Hz / 6dB passive crossovers like my Heathkits. There must be a fudge factor there.

FWIW, I have a Behringer 2496 active XO and will eventually be bi-amping my system. I can adjust slopes to 24dB and tune the final XO point anywhere I need it to be.

Yes all horns have a roll off built in at the low end of the range and maybe skilled crossover guys can work with that but in my experience you have to stay away from the cutoff with the crossover point of you are asking for trouble and probably will get a notch in the response.

Also I think the sound of an unloaded driver is probably not so good below the cutoff in addition and may even have some distortion if near driver resonance.

Maybe there are some horn designers out there who could elaborate on the problems of crossing at the cutoff a little better than I can.