Enclosure Help - 2 FI SP4 18s

[AceAnderson]

Hi guys, I'm designing a box for a someone who'll be competing with it at State finals, so I'm really trying to get this right. I've been out of the car audio world for about a year now, so I need some refreshers. I'm designing a box for two FI SP4 18s at maximum allowed volume, 32ish hz. It's going in a Chevy Blazer, and the back seats will have to be folded down to make it fit.

I've came to the conclusion that we really can't do a center port, or even dual side ports because of space limitations (36" wide, 2 18" subs = 0"), so I'm opting to put the subs on top (he wants to invert to show off the basket work he did), and using a regular slot port on the side. Here's the model so far with the specs, let me know if I'm overlooking anything wrong

Click to read more...

 

[Hertz Mafia]

Build the box over the wheel wells. Should be able to get wider then 36" that way. My buddy had subs up port up in a blazer with two 18s on a DC 3.5k and would do 150db+ on music

http://www.caraudioclassifieds.org/forum/dc/96286-2x-18-xl-box.html

Gives u an idea of the box design and subs and port location

 

[AceAnderson]

I think we're going to stick with the dimensions we have currently and make the best out of them. Did you see anything wrong in those numbers?

 

[Hertz Mafia]

Port looks kinda large and the woofers might load uneven with one kinda being in the port and the other having the port wall

 

[Hertz Mafia]

@Jeffdachef @CSCStang

 

[AceAnderson]

I was worried about that actually, I didn't know if that could cause an issue... With regular dual ported boxes though, one sub will always be closer to the port, right? Just kinda how it works? We were possibly considering an aeroport

 

[Hertz Mafia]

I was worried about that actually, I didn't know if that could cause an issue... With regular dual ported boxes though, one sub will always be closer to the port, right? Just kinda how it works? We were possibly considering an aeroport

Then make separate chambers and each woofer gets its own port. Try and keep it symmetrical

 

[Jeffdachef 5,000+ posts]

I was worried about that actually, I didn't know if that could cause an issue... With regular dual ported boxes though, one sub will always be closer to the port, right? Just kinda how it works? We were possibly considering an aeroport

bottom port or square port works too.

 

[AceAnderson]

Also, I know this is a big box, but to get good port numbers i have to have the port be a foot wide or so. That seems like too much? How big of a port is too big? It's got a decent ratio and should be enough port area per foot though