Hello everyone,

I'm curious if theres a general rule of thumb for the number of bends in a port? I've built a couple of boxes before and always ended up with a little bit of port noise but I've also always used shorter round ports (3" in diameter by 9.5" in length in my most recent box). I recently traded that sub for two older 8" Kicker L7s and plan to build a new box for them.

I've been working on a design on WinISD Pro and I came up with these specs; 2 cubic feet, tuned to 31.045 (to correct the port length) with square port dimensions of 10.5" tall and 2.5" wide and 33" long.

Now this box is possible in my car but I was wondering how to execute it. A port with a single bend with the port starting in the front and bending at the back, but this would cause me to need a relatively wide box.

Or no bends at all with the port on the side, though this would cause me to almost have the port right against the side of my trunk (a big no-no if I understand correctly).

Or maybe like a sandwich of bends going from the front to the back of the box, but does this decrease the ports efficency like how bends in your exhaust rectrict flow?

Thanks in advance,
Kidd

 

All bends restrict flow regardless of the flow medium and restriction have a direct effect of efficency.

With respect to enclosure bulding you may not notice a difference. I am not aware of a rule of thumb on the number of bends in enclosure bulding, however I have seen slot ports enclosure where the ports have 1 to 4 bends, and 45 degrees strips are used in the corners to aid the flow, how much difference does it make? Again may not be noticeable.

 

a) That tuning sounds too low for a pair of Kicker 8's IMO
b) I also look at bends similar to exhaust, or home HVAC, when every bend cuts down on efficiency. Can you use a long-radius pvc elbow to get the bend you need? They're nice gentle curves which are smooth and when glued with straight pipe, make for great, easy box port.

 

Thanks guys,

I ended up going with a smaller sealed box in the cabin (behind the center console) but I wanted to thank both of you for your input.

 

Glad you got it worked out.

 

keep in mind with ur small sealed box u can make a bigger ported box tuned high and throw that sealed one inside for a quick fourth order experiment