Bass reflex enclosure

Hello all,
I am building a subwoofer and I am trying to figure out what port diameter to use. The factory specs for the sub say that I should use a 2.5 inch diameter port tube, but this is only for one port. My question is wheather I can use 2 ports of 2 inch diameter? Will I have problem with port turbulence because of the smaller size?

I don't know what I would do if I didn't have this forum to answer my questions.

Bear in mind that the longer the port is, the more it tends to achieve a life of its own. The air acquires enough momentum that it becomes difficult to stop once it begins moving. As such, you get a lag between the port response and the driver; a distortion mechanism, in other words.
Better to use a short port...but then you end up with it being narrow in cross section, hence more likely to make noise.
Your choice--just be aware of the tradeoffs.



2001-12-31 5:49 am
If you REALLY want to know about the port size, you could download WinISD and enter in your speaker parameters if you know them. It has a utility that determines the mach number (air speed velocity) in the port for a given size. It can give you and idea if your port is too small or not.

Just a suggestion. Good luck!