Why are most ports round? (1 Viewer)

[Bob Sorel]

Most times when I run a sim on a subwoofer, I always seem to specify round ports, even though there are options for rectangular ones. Is there any compelling reason to make a port round? Or do rectangular ports serve as well?
On a related topic, I often notice that some people prefer dual flared ports (on round ones, of course). What effect does the flare have on the port? Can you get away with a slightly small port by flaring it? Or are non-flared ports just as effective, but perhaps less aesthetic?

 

[Chris_Brunhaver]

Well, a circle has the more area per circumference as compared to a rectangle in area versus perimeter. This leads to less frictional losses. One larger vent is better than two smaller vents equalling the same area because of reduced frictional losses as well. Flaring a port decreases vent turbulence somewhat though the vent has to be a bit longer then a non-flared vent.