Yeah I know they do. I just (maybe incorrectly) thought that the location of the port was pretty crucial (I.e. a port off the bottom delivers some thump but on up high would let a lot of higher freqs out.Friedman cuts a small port in the back panel to let it breathe a little. I was going to cut some panels to try it open back, but I happened to leave the handle off after swapping in an Alnico Cream and M65 pair. I got a pleasant surprise in the sound with the opening. This leads me to think that either open back panels or a ported panel that I make for it will be a good sound. I had to pull the handle out in order to remove the back panel, so this was just by chance.