How far can swiftlet sounds be projected by tweeter?

This is a question of curiosity I had for a while. I did read about how the atmosphere attenuates different frequencies unequally over distance. I don't have a definite answer until tests conducted.

This would be one interesting up coming exercise. I surveyed my area for a quiet spot a good distance away. There is clear line of sight to my roof top without obstruction. Estimated its distance on Google Earth to be 2.63 KM. Once told Pak Hen I want to make a long range caller to go 5KM. He looked at me and said, "You are crazy!" Well, looks like I can contend with half range to begin with. He is correct, now I think I am crazy too.















Like to see if my long range tweeters can project sound that far! It's also about pushing the envelop.

The last time I did field tests was with Victor (of Yen Yen blog) back in Singapore at perhaps 300 meters. An industrial area void of residents was chosen and test conducted late at night. Even then volume was not turned on too loud as it drawn on weary passerby. Those were normal tweeters tested, ones used for external sound. Just a simple listening test with human hearing.