displacement of 45's

[husker77 10+ year member]

Is there a rule of thumb or something to figure how much displacement you lose from putting 45's in the corners and such. I know I can use math to figure it out but to dumb anymore to figure it out.

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[gckless 5,000+ posts]

Depends on the size of your 45's. Easiest way is to measure the area as a square, solve for area, then cut in half.

 

[husker77 10+ year member]

3" wide at the large end seems to be standard.

 

[av83 10+ year member]

3" wide at the large end seems to be standard.

If I'm just altering a box that is spec'd w/o 45's, I only put one in the port. Just make it big enough to maintain port width at the corner.

 

[mat3833 10+ year member]

from what i understand, when ur adding 45's to the port, you dont have to subtract anything. since you are adding them to keep port width more consistant and help improve airflow. when i build my boxes im actually going to try to make the port turns half circles instead of 90* angles. still not sure how im going to accomplish that but if it works i will be happy, mainly because im going to have a Folded port, not just an L port.

Matt

 

[husker77 10+ year member]

I was referring to 45's in the corners.

Well I did the math, when using a 3" wide 45, it looks like you lose .0026 cubic feet of airspace for every inch of brace.