3 ms·
Minor factoid: While that’s true in the limiting case (far away) for rock concerts, it’s common to use line arrays which fall -3 dB when you double your distanc
by klodolph 7y ago
Minor factoid: While that’s true in the limiting case (far away) for rock concerts, it’s common to use line arrays which fall -3 dB when you double your distance, as long as you’re within a certain range. Within this range they follow inverse rather than inverse square.
- dmoy 7y agoIs that a similar effect to antenna arrays?
- Cerium 7y agoIt is most similar to the effect of electrostatic charges. The effect of a point charge is the inverse square of distance, the effect of a line charge is the inverse of distance, and the effect of an infinite plane has no relation to distance.
- dmoy 7y agoOk thanks that is a useful mental model
- hunter2_ 7y agoIt's more similar to an antenna that isn't an array. But you could compare an antenna array to a microphone array, sure. They both work by tweaking the phase and relative gain to arbitrarily change directivity without a need for physical directivity techniques. Like how home voice assistants and multi-antenna wifi APs achieve long distance reception without also amplifying 360 degrees of noise. They do a thing not unlike camera autofocus in that they quickly home in on whatever optimizes s/n.
- hunter2_ 7y agoVery true. Most other things are approximately point sources, and even then it's unpredictable until you're at a sufficiently far field. And then there's free space, half-space (as with a wall mounted dryer), etc.