EPerez

Yea no problem. You could make the width 5 1/4" if you want also.

You would probably get your answered quicker if you called/emailed FI.

Port area doesn't come out to cubic feet. The port displacement does, but not port area. Port area is just the height multiplied by the width of the port. I would make your box out of 3/4" and have a double baffle on top. So if 18 is your height of your box then the port height would be 15 3/4" and then have the width 5.5" which is 86in2 of port area. However your dimensions are way too small. You need more depth so the tuning will lower and the volume will go up.

multiply your height, width and length of your port in inches and then divide it by 1728.

It's just how much the port takes up. When you download the calc it will tell you everything you need to know

Are you trying to find the port area per foot? If you want to download it again, I can help you understand it.

You should download the torres box calc. Type in google "torres box calc" and it's on the s m d forum. It's a very helpful tool. This way you can do it yourself and it'd be easier for you just to do it instead of asking and having to wait.

I would do 80 to 90 in2 of port area.

You can't make a box without knowing the amount of port area you need. You can't just keep making sketchups and ask if they're good. Ill check and see how much port area it should have. How much power are you puttin to the sa12s?

Well of course the box needs to be bigger. What's your max dimensions you can/want to use. For that box you came up with, I wouldn't put either of the pairs in that box. Your going to need a bigger port. How much, I don't know. I would have to get the specs of the subs. I'm not really sure if you would hear much of a difference between the subs. Both are proven to be some badass subs.

Just make an offer!

Bump!

If your really serious into gettin the highest DBs then you should invest into an spl meter like Shizzzon is suggesting. He has a company that sells them. So look into his.

If the port is facing forward and not sealed off than it will probably be better to just have port and sub face rear.

Exactly!! That's why I was thinking he was not happy with the 18 BL. I'm sure if he had a good design and was built right, he would of been happy with the output. Either way this sp4 will do the job.

Not sure what suv you have but how about 2 15 gcons? That would be way louder and sound just as good.

Hahahahah that guy has no defense!!! There's no difference in building a box for a 15 or an 18. The box is just bigger in all aspects like net volume is bigger, port is bigger(well depending on sub but usually is) and the cut out for the hole.

Ill check you dimensions in a minute but first doubling all around wouldn't be nessessary unless you're competing and need every tenth of a DB. I would do single everywhere and double up on baffle. Then Bracing where it needs it. The zx2500 will be plenty for that sub. The lowest you can run the kicker amp is 2 ohms right? Did you order a dual 1 ohm? In your 3rd paragraph, I don't really follow you lol you don't need to make it more difficult than it is. Go in Torres and keep messing around till something works. Just make sure the port length doesn't go to far into the side wall. What do you mean by low? (Give me the hz or a song?) what do you mean by highs(hz or song?). People have completely different ideas of lows and highs. But with the music you said you listen to you should be fine with tuning around 33hz. Ohh and is the sub and port on your box facing forward? The port needs something hard for it to unload.i would put te port towards the door and maybe sub up.

If no one has helped you by tomorrow after noon ill take a look at everything and help ya out.

Gotta post pics

Glad you like it. I gotta figure out why the photobucket isn't working and then ill send more.

This is the only way it'll work right now. I don't know why my photobucket uploading button won't work. Right click on the pic and hit open. Then when it goes to my gallery right click on the pic again and click large view. It'll go to a bigger pic. I have to work in an hour. When I get home I'll try to get some better pics.

Box design is all complete. I should have the sketchup and cut sheet for you by 4.