I'm hoping someday I can purchase a little aluminum box DSP FIR correction / crossover with four analog outputs, for $100 (inclusive of any "plug ins" that might be needed) - that's when I would finally call it "low cost". If it had to have only 2 analog outputs, that would be OK - physical "passive" crossover could be implemented which has the purpose of only LP for the woofer and HP for the tweeter (with phase alignment between the two drivers of course) then FR level for the overall system is implemented in the FIR correction...
If it costs much more than $100, then it seems to make sense to purchase something like an Intel MINI PC? (Because that can also act as a multimedia server, controlled by wireless touchpad, and use HDMI output for audio)
Maybe that is still too much to ask for in 2016? Perhaps next year?