Audio Spotlight

[abu]

Hi
Anyone know where I can get hold of/make an audio spotlight. these are new type of loudspeakers which send sound to a specific area by using some kind of carrrier wave. They are available commercially but are expensive. I need to send sinusoidal audio signal to a distance of 10 metres ( nothing complex or fancy)

[Externet]

Hello Abu.
You will get better results at higher frequencies (over 500 Hz ¿?), the bass range will reach, but spreads too soon.
Get a solid (not mesh) parabolic reflector from a discarded satellite antenna and position the speaker cone center exactly at focus aiming towards the parabola. The smaller the speaker, the better directionality; the larger the parabola, the longer the range; use an enclosed speaker for decent front-to-back ratio results.<p>Miguel