sealed subs sound different from ported subs...rythmik takes pride in making their ported subs to sound as close to sealed as possible but still different. just be aware that they are different. same goes for different port designs sound different. ofc if you arent comparing at same time, all the choices come recommended. good luck.
Power: Marantz sr7008, NAD C 275Bee x 2, Video: Oppo 103, Samsung 75un6300 LG oled c9 77
Speakers: Focal aria 948, Focal cc900, Klipsch synergy KSF 10.5, Magnepan LRS, Audioengine A2+
Subs: Rythmik FV25HP, Rythmik FV15HP, Velodyne HGS 12, Velodyne VA1512