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View Full Version : aeroport length for 2 rl-p 12s in 4 ft^3?



Lil Poot
03-14-2006, 09:57 AM
i asked a friend of mine who is very knowledgable with enclosures and f-bodies (but puts a lot of stock in modeling programs, which i dont) to help me with the port designs on my box. i was shooting for a 4 ft^3 @30 hz box, when i asked him about it, this is the reply i got. he recommends 33hz, but i was shooting for 30 because i want this to hit LOW.

To be honest with you, I think 4 cubes for those 2 subs is too big. The Qts on these subs is so low, that they really want a smaller box. I found that 1.5 cubes (each) tuned to 33hz gives a nice flat response. With the 1.5 cubes per sub (3 cubes total), you'd need 2 4" ports at 17.4" long each, or 3 3" ports at 15" long each.

If you jump up to 2 cubes per sub (4 total) tuned to 30hz, the response thins out between 40 and 70hz, which I feel will hurt your overall bass response. But... at that size, your ports would be 15.5" long for the pair of 4" ports, and 13.37" long for the 3 3" ports.



i was thinking 2 ft^3 was perfect for a ported rl-p 12. should i go ahead and do the 4 ft box or take his advice and do only 3? for the ports im using 2 4 inch aeroports. are the lengths he gave me about right? anyone else have any thoughts on this? if i have to, i can build it another inch and gain about another cubic foot, so i can go up to 5 if i have to.

its goin in a firebird trans am, so the design is quite unorthodox. here are some pictures of my current sealed box. im basically going to build the same thing, just with a rectangular section extending about 1 and a half feet up to the backs of the back seats, box will be completely level at the top, and the added section will be 4-5 inches tall. im going to start on the box on my next day off, just going to build it, then get the exact size to cut the ports but i think i'm going to do it right at 4 ft. ill get plenty of pics :naughty:

someone told me i might be better off with 2 4.5 inch ports a bit shorter than 4 inch ports and longer, but i couldnt find them anywhere. links to good prefab ports?

http://img65.imageshack.us/img65/7316/dcfc0023large6wu.jpg

http://img138.imageshack.us/img138/5315/dcfc0022large4xi.jpg

http://img53.imageshack.us/img53/7671/dcfc0025large1ut.jpg

Lil Poot
03-20-2006, 03:13 PM
bump.

in the middle of building the new box now, need to make the final decision on the ports. im going to use 2 4 inch aeroports. the subs are going to be in the same place. would i be best off having the ports in between the subs firing upward, or on the front of the box firing forward? does anyone know the diameter of the 4 inch aeroport at the widest part of the flare?