Originally Posted by
Z R I D E R
I have a Hornit, it's so loud and I've used it with great success many times. It really helps me when drivers are turning into my lane and can't necessarily see me due to obstructions (like parked cars, trees, etc.). I really like that I don't have to worry about pumping anything up (runs on batteries) and it has a trigger that can be placed wherever is most convenient for your finger to push it.
Downside: the louder of the two sounds that it produces is unrecognizable to most people, unlike the airzound which clearly sounds like a horn. The Hornit just sounds like a crazy loud and fast siren, and not everyone will react to it in a way that you want or react to it at all. However, I've had way more successes than failures with it so far.
I agree with this. I like the sound of the AirZound much better, but I like the reliability of the Hornit. I'm using the Hornit now.
Originally Posted by
Z R I D E R
I could be wrong, but this problem has more to do with physics than it does the diaphragm material. As the temperature outside decreases, the temperature of the air inside the bottle will also decrease which decreases the pressure that was built up inside. The atmospheric pressure also plays a role in the problem.
PV=nRT for an ideal gas (for which air is not, but..)
P is pressure and T is absolute temperature. 32F is 0 C is 273 Kelvin. 25C is 77F is 298 Kelvin. So this suggests that pressure should drop 10% over this temperature range. But the effect seems a lot worse than that. So I think it is the diaphragm reacting to the cold (or maybe water droplets freezing on the diaphragm???) more than the lack of pressure (particularly since it doesn't seem to have a problem just over freezing, but gets bad quickly).