Box for 4 SA-8's

[Dodgedakotafan]

ok i want to buy 4 SA-8's to put in my dodge dakota extented cab, they will be run off a AQ2200

now im not very good at box designing so i wanted to confirm/ask opinions on this box

it will be 3.2 cubes (roughly .8 cubes per sub) with 2 4" aero's with a length of 14.35 inches each, that should make it tuned to 35hz.

does that box sound good? if not feel free to give advice on this box. Thanks!

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[hatedonmostly 5,000+ posts]

Depends on who you ask...I'd say too little port area

 

[Dodgedakotafan]

what do you suggest i do for aeros then? im not really sure, i was just taking a stab in the dark on this one.

i forgot to add, this will be daily driven, id like to have it sound as good as possible on all types of music, from rap/hip hop to metal

 

[supermaxx123 10+ year member]

I'd do 4 of those ports

 

[supermaxx123 10+ year member]

I also hope you took into account the subs airspace along with ports, pretty big subs. should sound really good though with your airspace/tuning and proper port area.

 

[Dodgedakotafan]

yeah i took into account of sub displacement, i figured about .1 cube per sub, overall the box should be roughly 3.7 cubes before displacement.

you think i should do 4 4" aeros? wow that seems like alot. that would make the aero's 31.63 inches long though, thats far too long

well honestly im using this calc http://www.carstereo.com/help/Articles.cfm?id=31 so when i type in the enclosure volume i should be typing in the cubic feet after displacements correct?

 

[supermaxx123 10+ year member]

seems like a lot but it's what needs to be. You might be safe with 3, personally i'd run 4. this sub moves some air.

 

[Dodgedakotafan]

ok so if i do a 3.2 cube box (after displacements) and use 4 4" aeros, the calc is telling me i need to make the aero's 31.63 inches long, and i just dont have the room for that and i would rather not have the ports outside the box. hmm im at a loss of what to do.

 

[supermaxx123 10+ year member]

try 3, would be better than 2.

 

[Dodgedakotafan]

hmm even for 3 4" aeros it would need to be 22" long for a 35hz tuning. i wish i was better at this, this is only my second time designing/building a ported box

 

[Bumpin' Goalie 10+ year member]

Aeros are tricky like that. To achieve anywhere close to daily/low tuning and maintain "proper" port area length is CRAZY.

PSP Flared Aeros help with the flares. Though still hard to judge. One 12-14 of port area via PSP Aero for ~ 2 liters of Displacement seems to work well for me so far.

 

[supermaxx123 10+ year member]

i had the same problem, had to tune to 37hz, sometimes space can be a challenge. only fix would be passive radiators but unless money is not of limit, i'd say try a higher tuning.

 

[Dodgedakotafan]

hmm yeah, right now i have an AQ sdc2.5 tuned to 38hz, i like the way that sounds, so i might try tuning to that again, i just wanted to try something different.

 

[Bumpin' Goalie 10+ year member]

hmm i may just go with a slot port design, seems simpler unless i can figure something out with these aeros

Have SD and Xmax on the SA-8's? Can't recall them.

SD (in CM^2) * XMAX (in CM) * 2 / 1000= Displacement in Liters.

1 4" Aero has 12.56 port area.

2 4" Aeros have 25.12 port area

3 3" Aeros have 21.195 port area.

Those would be your best bets depending on liters of displacement.

 

[supermaxx123 10+ year member]

can't expect them to sound the same even at the same tuning. maybe try using 3 subs and 2 ports.