Active line level crossover with subwoofer out - HELP


Hi.

Helping my friend with another challenge. 
Looking for a line level crossover. His preamp does not have a subwoofer out.

What he wants to do is have a high pass filter between the preamp and his power amp. This so his Spendor BC1’s are spared anything below 40 or 50hz. And, the crossover needs a low pass filter to spare the subwoofer the high frequencies. 
Thoughts? 
Thanks!
perkri
Mostly valuable opinions here.  I, too, am investigating an actual active X-over to take everything below out of the signal to my amp and LRS's and send it to at least @ powered subs.  Those subs can be positioned to reduce nodes.  The miniDSP HD has a x-over, HPF & LPF and by plugging in a PC, Mac or phone app, I believe, 25 bands of parametric EQ.  My concern is if the sample rate of this device will nullify the resolution value of my DAC.  The miniDSP HD apparently is 32bit & 192k.  The new $60 dsp from Parts Express doesn't say. 
Good morning all!

Thank you for all the input, thoughts, ideas and popcorn worthy (at times) lively discussion!

Some more info...

My friends place is not set up as a critical listening system/room.

(One speaker is in a bookshelf, the other on a stand further away, the sub is placed in a seemingly good spot, vaulted ceilings, listening area is off to one corner where "desk is and, to make things interesting, there is a large pre war Steinway grand piano in the room...)

This is very much a lifestyle system. That doesn’t mean, however, that the goal isn’t the same as all systems which is do what you can with what you got and try to optimize as best as possible. My goal is to work with what is there, with some hopefully minor changes, in order to have the sound that is flooding the room sound good!

So, because of the shape of the main area and the rather unorthodox set up, bass nodes are not really a big problem. (Walked around the space many times, and there are no "blank" spots or "areas of pain in the bass")

Another bit of info, forgive the pun, there are currently four sources. Turntable, CD to a Dac, Tuner and a Bluetooth device for You Tube/Guest phone stuff...

Many products to research, thank you!
My concern is if the sample rate of this device will nullify the resolution value of my DAC. The miniDSP HD apparently is 32bit & 192k. The new $60 dsp from Parts Express doesn’t say.


Yeah, this is an issue. This is why I run purely digital EQ (roon right now) or only in the subwoofer.

These DSP based EQ systems have to deconstruct the incoming analog signal, do math on it, and then have a DAC to turn those numbers back into voltages. Not really some one who spent a lot of money on a DAC wants to do.

Using a digital only EQ solution, which does the math BEFORE your fancy DAC gets around this, but doesn’t have a solution for your subwoofer. I use

For the OP, who has 2 speakers in two different locations, plus a sub, though, he’s really going to need EQ to match the L and R plus integrate the sub. Having a fancy DAC is the least of his worries.

Of course, other solutions include a digital preamp with built in EQ. :) Anthem makes them as well as integrateds, and built in sub out, with automatic configuration.
Which war ?

fun room, sounds like a music lover

Bluesound DAC or NAD more than adequate 

have fun !!!!
No idea whether either of these will solve the problem but Parasound Halo preamps have sub out with adjustments
and

Emerald Physics has the BOM