This is a video of our model 5 running on new years. This recording has some awesome echos in it. The siren is in a building that was open to the side opposite of the camera. You can hear more of the high tone in the echo because the wall muffles out a lot of the high tone.
Here is the link:
http://www.youtube.com/watch?v=ldnvU7Ht ... ature=plcp