Passive vs. active crossover?

I know I am beating this to death , sorry but it's my nature just look at my turntable I never stop.
So my question is : my system sounds incredible now, I have my preamp output going into the sub's input and a high pass going from the sub to the power amp. But it is single ended and I prefer running my pre to power with balanced. Will it be easy to make a filter that removes say around 40 hz on down using balanced ic in a passive circuit. Or should I stick with active? And which one?
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Most analog active subwoofer crossovers only allow low-pass adjustment of volume level, ect, (the active part)....the hi-pass output is fixed, except for maybe crossover point choice, and in some cases filter type.

An active subwoofer, used with a passive hi-pass filter, is really not different then.....yes?

Note: My comments refer to the price ranges you have been researching only.

To go from single-ended to balanced with passive components would require use of a transformer. Don't waste your time and money.
I highly recommend the Marchand XM-44, because you can tweak the slopes and crossover points. I went with the upgraded attentuators with one-half dB's per click. Mine has no noise problems. Mr. Marchand knows what he's doing, and will advise you well vis-a-vis choosing the optimum slope, etc.
The Accuphase F-25 active crossover is an excellent unit. I use one myself.