I use the SPL Crossover from Germany. It is an active crossover that allows the user to adjust the crossover point and slope to both the sub and the power amp. JL also makes an excellent active crossover.
Electronic cross-over on pre-amp out, to split signal to subwoofer and bookshelf speakers
I have a 50 W amp for 86 dB bookshelf speakers.
I really want to keep both amp and speakers.
My idea is to have an electronic crossover on preamp out, split the signal say at 80 Hz - Send the lower electronic cross over out to a subwoofer. Send the high crossover out to my existing 50 W power amps.
This would extend speaker frequency range to subwoofer capability - say 25 Hz, reduce the power amp load and allow to play the bookshelf speakers a bit louder,/ have more headroom.
I am sure others have already done. What cross over did you use? Was it successful?