Directional Speakers
The DIY directional speakers are not difficult to build, as there are kits available on ebay and such, but are extremely low quality, pretty much unusable for actual installations.  There are commercial models available with much better sound quality:  http://www.audiospotlight.com

The Browns are just regular speakers, and won't provide any notable beaming. From the same site:
https://www.holosonics.com/sound-fields
https://www.holosonics.com/fundamental-limitations-of-loudspeaker-directivity