how to Implement a High Pass Filter in my setup


hi all , 
i would like to know what's the best way for me to limit full range signal going to my front speakers. 
and at the same time managing cross over on my two subs. 

in my setup where its source > Digital Coax > DAC > Pre Amp > Amp , i have read that this can be done with a high pass filter. 

i need the flexibility to be able to change the dAc or pre amp or amp depending on my future needs. 

the question i have are
should the cross over setting just be set on the subs themselves?
where does the sub plug into in this signal chain?
if using a high pass filter is the best solution - which one should i get ?


kearkg312
Thanks I think I kept getting confused between sending a stereo signal to the sub and sending a mono . 
So essentially there’s two options use HPF on sub or use HSU’s one

Which way would be better? Yes, after I get this setup I would look at buying a minidsp and integrating that

Would a minidsp work with either setup ? 
I have used that HSU filter when the sub that I was using had no high pass filter. If you use the HSU you can place it near your amp and you will only need a short IC to connect it. You might want to run your speakers full range and see if you like it then you won't have to bother with any extra cables. BTW, I no nothing about DSP.
I’m kind of leaning towards the HSU filter myself, that way if I ever change out the subs to ones that don’t have a HPF, it will be an easy swap out.