My conch horn has the point on thick end filed off smooth to provide a place to form your lip on. Talk about a shallow mpc, but no manufactured mpc is added.
Oh yeah, your neighbor might think an 18 wheeler blowling an air horn was about to crash into their bedroom.
Too, I think such would stampede cattle. Maybe put deer on the run also.
Now to make a trumpet "mute" with one. Anybody like that idea?