How much port area for two DC XL 15's?

[sprkn_ranger]

It's not about how much port area subs like, it's about the port area to net box volume ratio. I personally like 13-15in2 per 1ft3.

a general rule of thumb yes... ideal no

2 12s that move 7mm xmax in 4cuft do not need as much port area as 2 12s with 28mm xmax in 4cuft. its about volume displacement moreso than a sqin/cuft

This def makes sense...now Is there a formula that lets you figure out the amount of port needed based on the amount of Xmax and cubic foot of enclosure?

[ChevyBoy95]

i would say 130-140. and no, i am not crazy suggesting 23 per cube, all of my applications with DC subs turned out better with 18+ per cube, not to mention, gets louder to ear the lower it gets down to about 28.

edit: xmax is key, like decaf said.

[SPLadd1ct]

i would say 130-140. and no, i am not crazy suggesting 23 per cube, all of my applications with DC subs turned out better with 18+ per cube, not to mention, gets louder to ear the lower it gets down to about 28.

edit: xmax is key, like decaf said.

Are you stating that in your personal applications that you used 23 square inches of port area per cubic foot? For what DC drivers exactly? the XL line?

[Decaf]

120-140sqin should be plenty

[bkolfo4]

At least Decaf has the correct idea.

sqin and cuft should not even be used in the same sentence together. . .

[dohckiller808]

http://www.carstereo.com/help/Articles.cfm?id=31

[ChevyBoy95]

i would say 130-140. and no, i am not crazy suggesting 23 per cube, all of my applications with DC subs turned out better with 18+ per cube, not to mention, gets louder to ear the lower it gets down to about 28.

edit: xmax is key, like decaf said.

Are you stating that in your personal applications that you used 23 square inches of port area per cubic foot? For what DC drivers exactly? the XL line?

ive used the 5 in 2 applications, one with 16 per cube, turned out SHITTY! went will 19ish, slams the lows.

4 applications with level 4s, with 16 per cube, mediocre, and then 21 sqin, and murdered lows down to 25hz with 37hz tuning, and no thermal issues either.

~130 is my suggestion, for single 15s i like 60 to 70 sq inches or 120 - 140 for 2.

edit, the only time 14-16 worked well for me was when i used aeros for a single level 4.

[Cashdollar2009]

3.75ft^3 seems a little big for a 15" XL on 2k.

I ran my 15" XL in 3.5ft^3 on probably 2,000-2,200 with a single 6 inch aero (I believe around 10in^2 per ft^3) tuned to 32Hz and it liked to unload below 30Hz. I shrank to about 3.1ft^3 and made a few adjustments, tuning also dropped to around 30Hz and I could drop to mid-20Hz just fine. Before I get scrutinized, the port area was slightly less than what gets recommended around here and I still ran into unloading issues just a few Hz below tuning on that power in a 3.5ft^3 enclosure.

Just a thought.

[ChevyBoy95]

3.75ft^3 seems a little big for a 15" XL on 2k.

I ran my 15" XL in 3.5ft^3 on probably 2,000-2,200 with a single 6 inch aero (I believe around 10in^2 per ft^3) tuned to 32Hz and it liked to unload below 30Hz. I shrank to about 3.1ft^3 and made a few adjustments, tuning also dropped to around 30Hz and I could drop to mid-20Hz just fine. Before I get scrutinized, the port area was slightly less than what gets recommended around here and I still ran into unloading issues just a few Hz below tuning on that power in a 3.5ft^3 enclosure.

Just a thought.

flared aero was key to running that little port area.

[Cashdollar2009]

I understand with the flared aero application you can generally use a smaller figure for port area. I was just saying that on this forum, general suggestions have been thrown around for the longest time to use 14-16in^2 per ft^3 in a slot port application, and 9-12in^2 per ft^3 for an aero port application. Through these suggestions and numerous builds applying these suggestions I have noticed trending patterns. If he were to go by some of the suggestions he is getting on here, although they are not to be mistaken with these general rules because the general rules are incorrect, by coincidence, they match and if he plans to carry out with said suggested port area in such a large enclosure on this specific driver, I can foresee unloading issues at low-end frequencies if he feels the need to venture sub-30Hz.

(Note to what Decaf mentioned on this answer being driver parameter reliant, that is a nice simplified way to put it in which it makes sense.)

I am just saying though, take this driver, put it on 2k, work with the suggested port area, and then put it in a 3.75ft^3 enclosure and I feel you will have issues playing much, if any lower than tuning.

Just a suggestion from personal experience with this driver within his supposed power range.