But I can say that this will be used at noisy conventions,
2) Most speakers list their peak wattage. The RMS wattage is 1/2 peak.
3) I don't see a voltage rating for any of the speakers I've looked at, but I suspect if I use ohm's law I can calculate that based on the peak or RMS wattage and the speaker's ohm rating.
4) I suspect a speaker like this one with "dual 4 ohm voice coils" will draw as much current as a 2 ohm speaker:
6) That being the case, can I assume a car amp must be able to step 12v up to 60v?
Makes me wonder if the guys I know who have been hooking up two speakers to a wimpy amp that can only put put 7W have been doing things all wrong and they'd get the same volume out of one speaker... and even then they wouldn't be coming close to maxing it out.
(On a side note, I'm now thinking that a 4 ohm dual cone or dual coil speaker is still a 4 ohm speaker. But I'm still not certain about 2 way and 3 way speakers. I think those probably do behave like 3 4 or 8 ohm speakers.)
I'd still like to know how I can tell if I'm going to blow the amp up with the speakers I connect to it though.
Theres no AC power???
And of course, for stereo you need two speakers. Two speakers in separate cabinets can cover a larger area. And, two speakers gives you more cone area for potentially more bass.
Except... Some cheap 2-way speakers use a single capacitor as a crossover. This blocks the bass from the tweeter, and the bass "sees" an 8-ohm load. But, the high frequencies go to both drivers, and you've got 4 Ohms at high frequencies. (These speakers are usually marked as "8 Ohms").