Subs playing some highs.

[MrSkippyJ]

so if you do it long enough it overheats and can suffer damage?

A subs voice coil is cooled when the cone moves. If you are shoving RMS power through the voice coil at 1k hz then the voice coil is not moving enough to cool itself.

[Autruche]

Interesting, never thought of it that way, but it makes perfect sense.

[audio1der]

Interesting, never thought of it that way, but it makes perfect sense.

FWIW cheap electronic x-overs aren't worth what they cost (I have one, and can't wait to ditch it). I was much happier with a cap & coil, even though it meant sticking at one cutoff frequency at only 12db/oct.