Hello everyone,

This is my first post.I currently have 2 dd9518g dual 4 ohm subs,1 hifonics sampsom amp driving these subs in a 12 cft box ported to 35 hz with 140 sq in port. this system is in a 2007 chevy avalanche with the midgate removed.I currently hit a 149.5 db @ 47hz. I have 24 cft avaliable for a new enclosure for the new season and would like to try a bandpass box.This is a daily driver so i cant make any major mods to the truck.The truck have 2 layers of dynamat on the doors,roof floors and bed of the truck.I currently have a dual alternator setup with 6 kinetik hc1800 batteries for a electrical system.Believe it or not i also use this vehicle for sq also.I am wondering if anyone could point me in the right direction for the new build and design.

Hello everyone,

This is my first post.I currently have 2 dd9518g dual 4 ohm subs,1 hifonics sampsom amp driving these subs in a 12 cft box ported to 35 hz with 140 sq in port. this system is in a 2007 chevy avalanche with the midgate removed.I currently hit a 149.5 db @ 47hz. I have 24 cft avaliable for a new enclosure for the new season and would like to try a bandpass box.This is a daily driver so i cant make any major mods to the truck.The truck have 2 layers of dynamat on the doors,roof floors and bed of the truck.I currently have a dual alternator setup with 6 kinetik hc1800 batteries for a electrical system.Believe it or not i also use this vehicle for sq also.I am wondering if anyone could point me in the right direction for the new build and design.

You should take this to the enclosure design area of the forum. Maybe send a pm or an email to poundthatsound or audibel and fisher customs about your design ideas.

Btw...welcome dude.

Edited November 12, 200915 yr by bigrank916

Hello everyone,

This is my first post.I currently have 2 dd9518g dual 4 ohm subs,1 hifonics sampsom amp driving these subs in a 12 cft box ported to 35 hz with 140 sq in port. this system is in a 2007 chevy avalanche with the midgate removed.I currently hit a 149.5 db @ 47hz. I have 24 cft avaliable for a new enclosure for the new season and would like to try a bandpass box.This is a daily driver so i cant make any major mods to the truck.The truck have 2 layers of dynamat on the doors,roof floors and bed of the truck.I currently have a dual alternator setup with 6 kinetik hc1800 batteries for a electrical system.Believe it or not i also use this vehicle for sq also.I am wondering if anyone could point me in the right direction for the new build and design.

What Amps do you have? And what does your front stage look like?

Big difference between the two. First question though is why a bandpass?

Bandpass enclosures can be very loud when tuned properly.alot of db drag vehicles in Europe use bandpass enclosure and have great sucess. I currently run 1 hifonics Samson amp at 1 ohm (8000 watts).

My front stage is a 3 way setup using DLS irdirium 6.3 using a jl audio 450.4 v2.

If loud, then 6th.

it's up to you but you got a design flaw since u not breakin a 150 yet with that much power.

One main thing i see immediately is your port area.

You would benefit GREATLY if u rebuilt a new ported box, stay with 12cubes NET and build a massive port using roughly 300sqin minimum, 500sqin recommended but may not have the room.

Make sure you built it as long as possible and test it. Take the port out, cut an inch off and test again and keep doin it til u get your highest score with this monsterous port then rebuild it permanently.

port area is way too small and tuning is too low for SPL.

Build a new box around 12cubes with 20^2 of port per cube tuned 40-45Hz. Make a port reducer to drop port area to around 12-14^2 per cube and drop tuning into the 30's for daily/sq.

I've built a LOT of DD/AQ boxes and set them up that way when possible...