Megaphone

[Znoober]

I need to buy a megaphone but I don't want to get lumbered with one that turns out to be really quiet. So... what kind of wattage do I need to be looking at? They seem to range from 5 to 25 watts, but I have no idea how loud those would be. Basically I need to make a helluva racket, possibly for cheering up emo kids and goths, and heckling rubbish bands at Reading Festival.

[tomd]

We've got a 45w one at work we use for rounding people up after fire alarms, but as you'll be up against a 30kw pa you probably wouldn't be heard very far anyway.