View Full Version : L port vs. straight port

04-05-2012, 01:27 AM
making a box for 2 vvx 12's 4 cubes @ 32HZ and am wanting to make a centered slot port at the bottom of the box. and was wondering if making the port without any corners change anything. basically want the external part to look like this Home Theater Sub Build - Realm of Excursion (http://forum.realmofexcursion.com/home-pro-portable-audio/74274-home-theater-sub-build.html) but dont want to make all of the corners on the inside. or are they needed? sorry if this seems confusing. maybe a box designer can help out!?! might just end up paying for a design... thanks

04-05-2012, 01:45 AM
Bends help reduce port noise. 45 degree corners allow support and move the air better

04-05-2012, 02:01 AM
You do have a really great idea. That was cool.

Moble Enclosurs
04-05-2012, 02:17 AM
Not only port noise but resonances also. When you don't put the 45s, or whatever angle you are working with, in the corners, it builds up pressure and that can cause peaks in the response at certain frequencies. Less noticable in substaging, but still beneficial to reduce that.
Nominally, the smaller the port area, the more sensitive it is to reducing port noise and less sensitive to resonance, and vice versa for increasing larger ports. So, a balance can be met for sure, but always better to be safe and utilize them when applicable.

The only major case when they are not as beneficial is for corners inside a compression chamber (main box volume excluding the port volume) where it is compression based, but for tline constants, they are and should be utilized nearly always on any bends/angles.