directional sound system

epilot said:

what this means please?

"it is impossible to generate extremely narrow beams of
audible sound without extremely large loudspeaker arrays" :roll:

Click to expand...

Sound from speaker transducers becomes more focused when an array of transducers are used together due to them all being in-phase on the axis of the array, and having phase-shift from colunm to column or from row to row for off-axis.
In-phase sound adds in level while out-of-phase sound cancels.
The size of the transducers and the size of the array is determined by the sound frequency that needs to be focused.