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View Full Version : what port length for 35Hz?



oldschoolboomer
12-25-2008, 02:11 PM
built 23.9 gross square foot "wall" yesterday. the port dimensions are 5.25 x 50.5 x ?????. I need to know how long to make the port for @35Hz tuning. Maximum length is 19.25 which I believe would tune to @29Hz which may be a bit low for se15's. Need help asap as I want to get the port in and start the bracing and finishing work today.

oldschoolboomer
12-25-2008, 02:17 PM
bump

hatemonger
12-25-2008, 02:29 PM
can you widen it a little? or is that not an option. say 7 x 50.5? then it would be around 16 inches and box volume would be around 22 cubes. i'm assuming you made a mistake by saying 23.9 square feet. it's 23.9 cubic feet? correct?

oldschoolboomer
12-25-2008, 02:35 PM
meant cubic feet. The port is only 5.25 tall due to space constraints. The overall dimensions of the box are:
24.5" deep x 37" tall x 52" wide. This is for 6 se15's.

hatemonger
12-25-2008, 02:37 PM
meant cubic feet. The port is only 5.25 tall due to space constraints. The overall dimensions of the box are:
24.5" deep x 37" tall x 52" wide. This is for 6 se15's.

well. my calculations are wrong then. what is the displacement for each woofer?

oldschoolboomer
12-25-2008, 02:50 PM
.17

oldschoolboomer
12-25-2008, 03:00 PM
bump

hatemonger
12-25-2008, 03:58 PM
13 inches. you'll end up with about 21.5 cubes tuned in the mid 30's

oldschoolboomer
12-25-2008, 04:45 PM
thanks a bunch. I have now finished all the bracing south of the port. 13 it is.

jdawg
12-25-2008, 05:12 PM
bracing take up airspace depending on what you use for braces

hatemonger
12-25-2008, 05:16 PM
bracing take up airspace depending on what you use for braces

agreed. box size will come down, and also mess up your tuning. especially if you use 2x4's. all thread won't take up as much.

jdawg
12-25-2008, 05:18 PM
all thread i wouldnt even worry with, but if its dowels or 2x4s, especially 2x4s if he used a bunch then it could up tuned pretty high real fast

oldschoolboomer
12-25-2008, 07:13 PM
I used 3/4" plywood cut 3" wide with 45's. I braced the crap out of it and maybe used the equivalent of 1 20" x 12" piece.

oldschoolboomer
12-25-2008, 07:14 PM
well maybe a little more than that. but not much.

Dutchie.
12-27-2008, 08:17 PM
The ideal port area is 12-16 in^2 per ft^3