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 ?