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


Purely analog crossover, you can add an EQ to the sub after.
perkri

He’s got Spendor BC1’s for a reason, for their organic sound when used just simply with source and amp.

Don’t go sterilizing the sound by putting mini dsp and or digital xovers in the signal path, as they have lousy d/a converters in them and if your friend has a good dac that sound will be lost along with the Spendors sound.

Get a pair of these passive HP filters (pick your frequency) on the input of the Spendors amps and use an active subs xovers/plate amp to blend it in to whatever you pick to roll off the Spendors at. Or if the sub doesn’t have an active xover then the use the LP filters on the sub/s amps as well from the same place.

http://vi.vipr.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=272942669723&t=1540585209000&category=14970&seller=speakeraddict&excSoj=1&excTrk=1&lsite=0&ittenable=false&domain=ebay.com.au&descgauge=1&cspheader=1&oneClk=2&secureDesc=0


100hz HP ones
https://www.ebay.com.au/itm/2-Harrison-Labs-FMOD-100Hz-HP-High-Pass-Satellite-Electronic-Crossover-USA-Made-/272942669723

Cheers George
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