Subs with focal katna 3s

System is upstairs is bryston preamp, dac, and roon/ quobuz streaming.  EAT flat turntable with ortofon black cartridge.  14b3 cubed amplifier.   I have an arc Mike and software I used with my downstairs anthem avm60 surround sound system but didn't know if it would mesh with the bryston two channel music set up.  I will take suggestions on a stand alone diagnostic device.  My cinema setup had goldenear Triton reference mains pushed by parasound a21s (2) with a carver sunfire cinema grand for goldenear aons as surrounds(4).   I know it's all ss with tubes, but that may be next experiment.   House built in 1923,wood floors, 10x18x36

You really want two sealed subs.  Arendal seems to offer high quality/$, and they include a setup app and a 60-day “risk-free” trial period (although I’m not sure of the details).  Worth looking into I’d think.  If you don’t require a setup app then Rhythmik offers a lot of performance/$ and a 45-day trial period although return shipping not included. Best of luck. 

@paliden 

We have REL S510s with our Kanta 3s in an open floor plan family room. They are definitely worth it. If your floor is a suspended wood floor you will need some isolation under all speakers. Good luck !