I currently have a marantz 40n with KEF R3 and SVS Micro 3000. It sounds pretty good, but I am struggling a bit to integrate them as I wanted since my room has a resonance peak right at the crossover frequency (even with the port plugs). Unfortunately the 40n does not have high pass filtering, so I was wandering if Apollo Hypex NCx500 with miniDSP Flex HT as pre-amp would be a good option, because it seems much cheaper than any other comparable solutions (such as NAD M10 or Lyngdorf 2210). Any suggestions?