1 18" ported vs 8 12"s sealed

[Serpent710 10+ year member]

18" BTL ported vs 8 12" hifonics hfi's sealed? which do u think would get louder on a aq2200d? never really messed with sealed boxes so i dont know much about em. thanks

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[RidnClean 5,000+ posts]

thats a lil obvious.

the cone area will win.

 

[Serpent710 10+ year member]

thats a lil obvious.
the cone area will win.

thanks. didnt really know cause of the sealed box.

 

[Brian Owens 10+ year member]

Nevermind - My brain read (1) 18 vs. (2) 18's, not (1) 18 vs. (8) 12's.

That is a BIG difference in cone area.

Brian

 

[spencer321 10+ year member]

this is a crude estimation BUT...

assuming 1200cm^2 cone area on the 18, and 480cm^2 on the 12's...

the 12's are 3.2 times larger in cone area, if you gain 3db evertime you double the cone area... than the 12's would technically be 4.8db louder, however, they lose approx 3db for being sealed vs being ported, so again... crude estimate but the 12's should be approx 1.8db louder than the 18

 

[Serpent710 10+ year member]

so technically if if i went with 6 12's and ported them i would be louder than the 8 12's sealed?

 

[spencer321 10+ year member]

so technically if if i went with 6 12's and ported them i would be louder than the 8 12's sealed?

yes

 

[PV Audio 5,000+ posts]

so technically if if i went with 6 12's and ported them i would be louder than the 8 12's sealed?

Absolutely. A double in power, an equivalent vented enclosure or a double in piston area = a double in perceived output, which in electronics is 3dB. Obviously for the middle one, you have a narrower passband in which the rule of thumb applies, but it's still pretty much the same. Now, that isn't to say that 12 ported will be as loud as 24 sealed, because there's so many factors that can influence, however, it's pretty much guaranteed that 1 18 will not hold a candle to 8 12s sealed, ported or otherwise.

 

[kfx450r 10+ year member]

Are those hfi 12s still 35$ shipped at electronix or w/e

 

[99grandprixGT 5,000+ posts]

ya u can get them on ebay for like 65 dollars a pair shipped.

 

[ThatChevyGuy 5,000+ posts]

Id go with the 18" ported if you want any lows, those hifi's dont do so well on low notes.

 

[PV Audio 5,000+ posts]

Id go with the 18" ported if you want any lows, those hifi's dont do so well on low notes.

Except that we're talking about such a larger amount of cone area that this point is irrelevant. 1 18 has a cone area of 9^2*3.14, or 254 sqin. A 12 has a cone area of 113 sq in. Eight 12s has a cone area of therefore 904 sq in, or over 3.5x the cone area. His lows will be just fine.

 

[ThatChevyGuy 5,000+ posts]

Except that we're talking about such a larger amount of cone area that this point is irrelevant. 1 18 has a cone area of 9^2*3.14, or 254 sqin. A 12 has a cone area of 113 sq in. Eight 12s has a cone area of therefore 904 sq in, or over 3.5x the cone area. His lows will be just fine.

Not if the subs **** *** lol. Have you heard them?

 

[DBfan187 5,000+ posts]

you're severely underestimating what a lot of cone area can do

 

[ThatChevyGuy 5,000+ posts]

Not reary, i know i had 3 of those ported at 32, and they sucked, and sealed, and they sucked more. There will be a extreme rolloff below 40 hz sealed