The conclusion I came to was that the particular crossover I was dealing with had an electrolytic in parallel with the speaker. The lytic cap just couldn't handle it. For people that don't necessarily know what they're looking at, and just trying to do what the OP is suggesting, it's a crapshoot.It isn't a crapshoot. If there are any shunt components (connected in parallel with the speaker that won't be used), they should be eliminated. Without the load of the speaker, their DCR becomes the load. depending on that DCR, they may burn up (often the case with coils) or look to the amp like a short at some frequency, which may cause it to go into protection.