Outboard crossover? Why not?

You have to be SURE that you have an internal crossover! :)

If so, then sure, jumper away.

The tweeter, for instance, needs at least 1 cap to keep it from blowing.

My current reference pair, there's no internal crossover at all, but you can't tell by looking at the outside.

Best,

Erik

Many thanks for all that. It is a price of not really paying attention on a purchase!
As Erik says, the non existence of an internal crossover may not be stated on the back, so what indications can I look for that I have or have not?
Surely jumping can do less damage (Tim thinks so whatever internals??) in any circumstances than triamping, if that is what it is called.? For those who do triamp do they really prefer all those speaker cables?

I am a BIG fan of not using speakers with crossovers inside them.  I use an active crossover (DBX) and it is between my preamp and amps, so my amps actually see my speakers, directly, not my crossover.  When you use internal crossovers, your amps never see the drivers, just the crossover.  

@tatyan69

You run the risk of very easily blowing your tweeter and watching it turn ballistic unless you know what's going on for sure. There's no "less" damage here, either is as risky.

If you have a multi-meter, connect it to the tweeter section. It should, over time, read infinite resistance.

If you get a number between 3 and 10, and it doesn't change after a minute, you don't have a crossover. :)

Of course, you could just take a driver or the panel off and look.

@tatyan69    If you don't have a separate box from the speaker,  the speaker has internal crossovers... You would know if your amp had an electronic crossover to adjust frequency... Jump away,  you will be fine....