Posted April 15, 201015 yr Im building an enclosure for a Bl 12 I would like to tune it to tune it to 32 Hrz only Im not sure how to get the results Im looking for the specs for the enclosure im building is 16" deep 53"wide 8" tall on the back side and 9.5" tall on the front side I plan to fire it up I will be running it 1 ohm with a T1000 fosgate amp can sombody tell me what size port and length to use round or slot pot ? total air space is 2.79cuft with 0.18 deducted for sub displacement its 2.61cuft
April 16, 201015 yr I actually get that you have 3.13 cubes before displacement. Assuming 3/4" wood, 14.5" x 51.5" x 7.25 (average of 8 and 9.5 minus 1.5" wood thickness) / 1728 sq in/ft = 3.13. Take out sub displacement = 2.95.As for port, a 30 sq. inch slot port 32" long will yield you a box about 2.2 cubes tuned to 32 hz.If you want to use round ports, you could use one 6" round port that's 27" long will give you a 2.4 cube box tuned to 32 hz, or two 4" ports 24" long (2.5 cubes net), or three 4" ports 47" long would give about 2 cubes net.IMO, slot port would be easiest.
April 16, 201015 yr Author I actually get that you have 3.13 cubes before displacement. Assuming 3/4" wood, 14.5" x 51.5" x 7.25 (average of 8 and 9.5 minus 1.5" wood thickness) / 1728 sq in/ft = 3.13. Take out sub displacement = 2.95.As for port, a 30 sq. inch slot port 32" long will yield you a box about 2.2 cubes tuned to 32 hz.If you want to use round ports, you could use one 6" round port that's 27" long will give you a 2.4 cube box tuned to 32 hz, or two 4" ports 24" long (2.5 cubes net), or three 4" ports 47" long would give about 2 cubes net.IMO, slot port would be easiest.
April 17, 201015 yr Author ok if I go with a slot port my box is shaped like a wedge in order to make it 32" long I will have to make an L shaped port and the port will narrow from the out side port opening to the inside port opening will this change anything
April 17, 201015 yr Yes. The port needs to be of uniform size throughout the port length.Maybe a round port would be easier, unless you were thinking of putting the port opening on a different face than the sub was on (like the side).
April 17, 201015 yr Author my sub will be an up fire on the top that is 16" deep if I put the port on the end opposite of the sub coming out of the end of the box will it still work the port would then be firing into the door but it should have at least 5-6 " clearance and just to make sure I understand you right the 30sq inches for the port thats the size of the opening of the port and just make it 32" long correct ? thanks again for all your help Im just about finished with it just makeing sure I put the port in right