4th Order Wall Design Help Needed

[nutnbutcustm 10+ year member]

I have been building systems for about 16 years I just never have built or messed with a 4th order.but i have decided no better time than now! so here is my info....

Purpose: street beat I want to do demos and do street beat in usaci so my goal is to do 160+ on music @47hz for 30 seconds at a time. I say 47hz because my truck peaks at 45 and 47hz is the track i have to use for street beat.

equipment: I have 4-12" B2 XC's being powered by 2-B2 M1's I could swap out to 15's but would like to stay with the 12's if my goal is attainable with them.

space: I have a 2005 Nissan Xterra that i can do anything with, my demensions are roughly 40"wide 36"tall 40" deep

i can go bigger but i would like to keep it this size or smaller to be able to remove the box to try different designs. it has a false floor "base" already installed. also would like to use a large aero port for the front chamber tuning rather than a slot port.

If you need anymore info just let me know, and if i need to pay you something just let me know.

B2 XC 12" specs

Power Handling: 6 kw ~ 15 kw*

Sensitivity: 86.1 dB

Nominal Impedance: 1 Ω

(Re):0.9 Ω

Resonanse Frequency (Fs): 38.3 Hz

Vas: 16.51 L

Qts: 0.331

Qms: 4.848

Qes: 0.356

Voice Coil diameter: 4"

I have tried to message @80inches but his pm box is full so anybody else have any advice? this is a huge build with some pricey equipment so please only help from guys that have built and have a lot of experience with 4ths please! and thanks in advance for any help!

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[nutnbutcustm 10+ year member]

87 looks and no replies at all??

 

[RangerDangerV2 5,000+ posts]

I do not see 160s with a 4th... youre only using the front wave and you risk unloding very easily... just do a flat wall.

 

[nutnbutcustm 10+ year member]

they are doing 160+ in italy with only 2 woofers in 4th orders, and yes you can unload if you arent careful but if you test,test and test and get tuning right it can happen.

 

[RangerDangerV2 5,000+ posts]

flat wall is much easier. and it will give you what you are looking for...

 

[mlstrass 5,000+ posts]

why would a 4th order unload, subs are in a sealed chamber.

Personally I'd go for cone area, so 15's at the minimum. Flat would be probably be your best bet, but a 4th order could do it also, especially if you build to get a decent bump around your peak...

 

[pro-rabbit 5,000+ posts]

A 4th can and will do what you want in that truck. Just don't expect it from the first build or two. If you go for numbers altering port position will alter your numbers drastically. The biggest over all issue will be getting the SPL port to peak with the truck correctly.

 

[nutnbutcustm 10+ year member]

this is why i want to use a aero port for easier adjustability, I have come up with a design i just havent built or designed one before, just looking for someone to either design me one or look over my design

 

[mlstrass 5,000+ posts]

just do port/loading wall out of 2x4's and screw in until you have it right, then screw/glue...