S.DeYoung

Be prepared to spend a lot of money on suspension upgrades to support something like that. The biggest problem with adding all that weight is going to be the stress on the tranny.

It probably won't be a daily driver anymore.

How much do the hcca's cost now. I have never been impressed with them. I bet you could find better woofers for the price. Any reason you have to run 12000wrms? It doesn't seem pratical to run that much power in a sealed application.

Drill hole through flair and screw down. I don't use glue when securing to the box.

On my phone right now. I can recalculate here in a bit. If those are your max dimensions, stick with the numbers above. Tuning may change 1 to 2 hz but it won't be noticeable.

Port size does effect tuning. So when figuring out box size you need to take size + port and sub displacement. Just adjust the total size and make it a little bigger. If you can't go bigger adjust the size to 4.25 and refigure port length and displacement will change. I have had great luck with two 12" SA-12s tuned to 32hz and 4.0cubic feet.

It will displace .48 cubic feet

Well if you are making them yourself. Three 4" Pvc ports. Each 22" long.

I would go with three 4" aeros. I buy mine from parts express. They are the psp brand. The problem you need with three 4" is they each have to be 22" long. Could you raise tuning to 33hz? This would mean you wouldn't have to cut them down, since they come in 17" kits.

Alright I just found that. So we have 19mm xmax, two 12" woofers and tuning @ 30hz? I come up with 8.92 MINIMUM diameter if using round ports. If using slot port then 62.45 inches.

What is the xmax of the SA-12?

First of all: in my opinion that is not enough port area. Would you consider building a slot port?

If you want to run 4000wrms and three 12s, you are not looking for sound quality.

Fail

Would you be willing to split them up?

The longer the port, the lower the tuning. I have seen a lot of vehicles have this problem. The box is tuned to 32hz but because of the cabin gains the vehicle peaks in the 40s.

Why do you need that much power for a pair of subwoofers that are rated at 600wrms each?

Why not a ported box with the port shooting into the cabin? Easier to design and build.

then what about the hifonics hf 2500 That is better than the SPL amplifier. I have not been impressed with Hifonics/Maxxsonics products lately. Check in the for sale section here and see if you can find a nice Sundown amplifier.

I would recommend going with more port area. In my experiences with the Xcons, they did better with more. I see your range is roughly 92 to 124. Shoot for the higher number.

The SSA Zcon is a great subwoofer.Those SPL/Power Acoustik amplifiers are junk. They don't do near rated power and have a tendency to crap out fairly quickly.

Rodents like to live under the engine cover, where exactly were wires chewed through?

I doubt they are made in America

No Idea. You haven't given enough information. Goals? What amplifier? Vehicle? etc. Also adding a period here and there would help instead on having one long run on sentence/paragraph.