what will a crossover do when over powered ? (crossover set to 300 and getting 450)

 

I'm guessing pretty much nothing as long as you set your gain properly and don't crank it up like a madman.

Every speaker in my car is overpowered, and I've got no problems so far. But, at the slightest hint of distortion, I lower the volume. And, even then, it gets intolerably loud before distorting I find.

As for the crossover itself, normaly they're able to take a lot more than the speakers, so I wouldn't worry too much. I've seen some caps in x-overs rated up to 250V...

250V in a 4ohm load = 15625W... I don't think your 450W could damage that too easily.

 

Depends on the crossover, in all likelyhood, nothing will ever happen since the tweeters will be on fire long before seeing that much actual power being fed to them. At worst, you might pop a capicitor if it's a cheaper component set.

 

don't most crossovers contain a PTC that will blow to save the tweeter anyway?

 

I should hope not. A fuse maybe, but a PTC would change resistance during normal operation too. Would likely behave a bit like an audio compressor.

 

You should be fine. To answer your question it will get hot and possibly have a shortened lifespan. Not something to worry about.

 

I'd be more concerned with the inductors. They will saturate which shifts their value - especially metal core inductors. And they'll heat up which can move their values too.

 

Good point. When an inductor is saturated it is effectively removed from the circuit. I would think that if they saturate it would be audible and hopefully the volume would be turned down. The distortion would be nasty.