edifier t5

Just needed to know if there was an alternative or better way to set up a new Edifier T5 subwoofer in my use case. I have a Fiio K7 connected to my PC. I have Edifier 1280DBS speakers connected to the Fiio K7. And now I've connected the Edifier T5 subwoofer to the parent 1280DBS speaker via...

So, the tops have a EQ control and Vol control, the subs have an EQ control and Vol control. How do I match them. And I don't mean "for the room". This may confuse people. ( Image you have a three way box: you have to match the three drivers to give an overall "flat" response, that is room...