anyway to make (economically) a smaller directional speaker

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Maybe 12 inch (or less) diameter and somewhat directional at 90 degrees maybe?
Are parabolic and/or directional speakers available or do they have to me "Homemade"?
Not much distance required 30-80 feet...
And just a noise or beep or ringing to make someone go looney
So is this possible??
I've seen a few things on youtube but no instructions as to how...
Any ideas?
Thanks

 

[miso]

https://groups.google.com/forum/#!topic/portable-sound-blaster/YxjJQ-6SpqI[1-25-false]