If you have clean bass you might get away with the low pass filter. I use the speaker inputs on my sub and let the speakers have full range. Just be careful not to over set your crossover. If you hear a bloated sound, lower your crossover until it goes away.
If your speakers go down to 50hz, start at 60hz on the sub and see if it works out.
Good luck.
If your speakers go down to 50hz, start at 60hz on the sub and see if it works out.
Good luck.