View Full Version : Box and Port info

01-24-2012, 11:13 PM
Building a new box.. Size as follows

= 2.24cubes

sub - 12" skar vvx
sub displ. = .18

box after sub displ. - 2.06 cubes

okay I want to do 2 4" flared ports anyone care to help me figure out the length of said ports
and displ after said ports are in to get around 28hz... or maybe even 1 4" flared port whichever would be best..

Amp is Memphis PR.1000.1 Sub is skar 12" vvx dvc2ohm wired parallel to 1ohm

I want the sub facing up ports either facing the seats or towards the back of the car.

car is 03 chevy impala... box will be all the way in the back against the seats so that i have trunk space... Wanting a 12" box so i can mount the amps on top of the box and be able to get to all of the wire/gains from inside the car from the back seat...

01-24-2012, 11:25 PM
idk if 1 4" areo would make the vvxs happy and adding another port makes it varder to tune that low .you will be sacrificing some high notes ibelieve if that 1 port dont do a good enough job

anyhow 1 port @18 inches =28hz
2 ports = have to be 43''s long and 20' external=28hz

correct me if im wrong

01-24-2012, 11:40 PM
hrm... wonder if I should just tune it back to like 34hz ... just want it lower than what i have it now in the L-Port box.... maybe do a slot kerfed at 2" :/ with side firing instead of port on sub side

01-25-2012, 02:13 AM
You would need 41inch long ports to tune to 28hz with 2 4in aero's in 2 cu/ft. You would be better off using 2 3in ports, those will run about 23inchs long for a 28hz tune in 2cu/ft. However you will be loosing volume due to the port displacement so your volume would drop by at least .2cu/ft, which would increase the length of the ports to 25inches.

Try something like this, I just made this box, 1.8cu/ft tuned to 32hz with 2 3in pvc ports about 17in long:


01-25-2012, 03:26 AM
hrm..... I'm at 1.3 or 1.4 after displ with the box i have now tuned to 33 or 34... was wanting to go lower than that or even in the high 20s :/ ....
i mean i can always go bigger and throw 3cubes before displacement... but i'm wanting a low profile box no higher than 12-13"s so I can mount my 2 amps on top of it....

01-25-2012, 05:01 AM
This is a perfect website for port lengths. Give it a try.
Products Menu (http://www.psp-inc.com/tools.html)

01-25-2012, 05:08 PM
If you went with 2 3in aeros and used the full 18inch length as they come, you would loose about .2 to their displacement, which would yield 1.86cu/ft and a tune of 32.65hz, just something to think about.

01-25-2012, 05:25 PM
only thing is i'm trying to keep the box no wider than 14" or 15" and port on the side into the cabin.. with sub facing up

01-25-2012, 05:34 PM
You can get pieces to make bends, whether pvc or actual aeroports

01-25-2012, 07:41 PM
guess I'll try to do some sketches tonight and see what kind of port / sub placements i can come up with including the amp racks I want to make
cause this setup just isn't cutting it anymore