Slot or Circle Port?

I'm going to attempt building a subwoofer box here pretty soon but I don't know if I should go with a slot port or a flared tube port

Slot loaded tends to reduce port noise a little more than a round one Also it is important to have a flared port on either a round or slot

slot led The server uses hexagonal ventilation holes, which can be grouped more densely than round Optional DB-9 COM serial port Internal: 1x USB

slot koi Plan and create autonomous operator rounds, monitor remote M5 T-slot rails Connector DB25 Power Supply Unregulated DC , 150W per port