audioguru said:
A number of speakers in a flat array focuses the sound because a little to the side, one column of speakers is closer than the others. If it is half a wavelength closer, the sound cancels.
epilot said:
sorry but i can not understand what you said!
If you are directly in front of an array of speakers, you hear all with the same phase and their loudness adds.
If you are off-center then one vertical column of speakers is closer to you, and other columns are farther. Measure the difference in distances and calculate the frequency that is a half-wavelength. That frequency will be received out-of-phase at your ears and be cancelled.
Don't you know about speakers' phase? Speakers and the air they vibrate must be moving in the same direction at the same time for sound to be loud.
Try it. Take two stereo speakers and place them facing each other with a small gap between. Play mono music. It will be loud if the speakers are in-phase. Then reverse the wires of a single speaker to make it out-of-phase. The bass and most of the sound will be gone. Don't forget to correct the wiring after this test. :lol: