View Full Version : help with first time "REAL" box in 240sx hatch

01-21-2012, 07:50 PM
im looking to make an enclosure for my 240sx (s13) hatchback.
what i have to work with is:
amp - hifonics 2608d (2600rms @1ohm)
subs - pair of 12in dc audio lvl4s d1
Mounting Depth
Mounting Hole Diameter
Motor Width
VC Diameter
.18³ ft
Magnet Weight
Power Handling RMS/Peak
Impedance (Ohm)
d1 or d2
494.00 cm²
66.60 L
1.95e-04 m/N
173.08 g
27.4 Hz
3.60 ohm
4.02 mH
23.5 mm
87.0 dB
Suggested Sealed
1³ ft
Suggested Ported
1.5³ ft

im wanting to do a ported box and have it tuned low to get the 240sx flexing but do not want to do a wall.
i want to be able to remove the box when needed.
and to keep the sway bars (X-bars) installed.

i was thinking if the port needs to be long i can have to port go in between the bar and the trunk floor.
my back seats will be removed and have my batterys and amps there.
so the spare battery casing in the back will be moved.

and the spare tire compartment, would that just be better to make a false floor and not even try to use that space?

heres pix of what im working with








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01-21-2012, 07:54 PM
just wondering why you want your car to flex. sure its coo to some, and helps some, but most dont want there cars to flex at all

01-21-2012, 07:59 PM
i need suggestions on whats the best application i can use for my situation here.

im wanting the do port design

what should the box be tuned to?

should i do circle port or square port? and at what hz?

this with be my first box build and would just like to do it right

double 07
01-21-2012, 08:22 PM
I have a friend that's a DC dealer and I do believe Rusty @ DC told him that 1.5 cubes net per sub (12" level 4) was perfect....I don't remember if he recommended a specific tuning but 33-35 would more than likely work just fine. As far as the box design maybe do subs up, port back or subs back port back......The second combo was louder in the civic hatch we done a while back......Some hatch cars work nicely with Aeroports......not sure........I am sure you will get more comments and ideas just hang out a while.......A lot of builders/designers on here

01-21-2012, 08:28 PM
We did set a few records back in 03 with a 240sx in USACi pro stock class. We had to modify the back panels a little to get a little more volume though.

As for enclosures though, are you wanting to make this simple or are you wanting to go a bit more in-depth with the design/build?

Also, willing to move the battery around a bit?

01-21-2012, 08:40 PM
ya the battery in the back will be moved to the rear seat area (with rear seat being taken out)
and the sway bars i was wanting to keep them in.

im trying to learn the sub box enclosure calculating software on the computer to help me out (but learning as i go along)

01-21-2012, 09:43 PM
I have a 90 240 sx, and did a pair of 1000 rms 10s ported/round in 3/4 mdf [email protected] mono.Dimensions on the box are L=36"x W=14" x H=14" dual chambers, and I had them on my Autotek Mean Machine [email protected],and the DB meter I had went Into error @135.So not sure what it really did, but it banged the entire vehicle,and made your throat hurt when the bass hit and the amp was @12"oclock position,0bass boost,o treble,and +5 on bass setting on hu,o loud button.I have eveything out now due to being in rebuild for engine.But ran 1 redtop up front, 2ga supply w 200 anl fuse to small motorcycle Optimus battery,and to agu fused 4 dist block 1 stinger fan on Autotek, and I ran a USA US Acoustics 4080 on my Polk MoMo 6.5 up front w Kicker KS 25 tweets, and a pair of Polk db 5.25 2ways in rear,with a Kicker KQ9 preamp.I deadened the tire well/spare tire area, and the entire flooring, built a false flr out of extra MDF, and painted with Rustolum paint to match to support my amps and box.easy to mount amps, and fan, and l bracketed the box stationary.Hit pretty good!!! Will redo after the engine gets replaced, and back here.All wiring is still ready to go.Just saying ..2 tens worked GREAT for the vehicle Airspace, and that box with the subs I used, and that amp was nothing but BRUTE!

01-21-2012, 09:49 PM
You can set that amp(onyx up on its side) with a bracket to retrieve approx 10 in more space also, and put the battery on the far rt side at the rear.A Kinetick 600,0r 800 will fit great in there.That amp will run cooler up on its side also, and prob wont need a fan to keep it running cool.Just a few suggestions.I will say this..That was the hardest wiring of any vehicle i have ever done.It took me 2 days, and evrything was a pain in the A##, but it was worth the trouble after done.:D

01-22-2012, 01:02 AM
ya all the wiring wasnt that hard for my but just took a little time lol

and the flexing part is just to say that a 240sx CAN flex lol but not really important.

but im having trouble trying to calculate the volume of my "imaginary box" becuz the front plate will be smaller than the back plate on the box im thinking of. (idk if anyone can understand what i am trying to say here..)

i kno volume=LxHxW but each LxHxW of each plate is different..

01-22-2012, 01:47 AM
ya all the wiring wasnt that hard for my but just took a little time lol

and the flexing part is just to say that a 240sx CAN flex lol but not really important.

but im having trouble trying to calculate the volume of my "imaginary box" becuz the front plate will be smaller than the back plate on the box im thinking of. (idk if anyone can understand what i am trying to say here..)

i kno volume=LxHxW but each LxHxW of each plate is different..

L x W x H= sum devided by 1728=cu ft. I had mine firing up towards the back glass to reflect towards the front.Sounded Great.Cant help you there.Im only good with true square measurements,Easier to do.Have you asked Pro rabbit or Ram or any other sub box builder?, or ran a thread on the Help 101 on enclosures yet?You may get a better response there?

01-22-2012, 02:25 AM
ya i was gonna do subs firing up on glass and ports either face front or back

but ya i thought i am in help 101 enclosure thread.. lol

01-22-2012, 02:31 AM
Hope you get it sounding good.Patience you know..LOL

01-22-2012, 02:33 AM
heres what i got so far

does anything look wrong here?



01-22-2012, 10:44 PM
im wanting to be tuned to 34 hz

would i be better of doing a
(my min. dimensions) 4.46cubic feet box with port sticking outta the box
(my max. dimensions) 6.685cubic feet box with port inside the box

01-23-2012, 12:01 AM
For a pair of 12s with 2600 watts on them i HIGHLY recommend increasing the vent surface area by quite a bit. I would recommend dual 6 inch aeroports at minimum. This would give you about 56 sq inches of port (14.36 sq inches per cubic foot)...as opposed to the 25 sq inches of port you currently have (6.44 sq inches per cubic foot)...assuming a Vb of 3.9 cubic feet that is.

01-23-2012, 12:02 PM
The issue with increase port area with round ports is the length to get the tuning one desires. It can become a nightmare very quickly lol.

01-23-2012, 12:25 PM
Oh I completely agree, but I would believe that having 25 sq inches of port on a setup like that would lead to some noise issues.

01-23-2012, 12:50 PM
If they are flared ports it would be fine actually, but that box is very large.

04-27-2012, 03:58 AM
heres what ive been trying to work on with re audio calculator

is any of this looking right?


04-27-2012, 06:56 AM
Get away from that ****** calculator it ***** and is very inaccurate and not good if your just learning.

04-27-2012, 09:42 AM
So I'm asuming what I did was all wrong?
The programs I have are bassbox, bassnotes, bassplots. Are any of these good to start with?

05-02-2012, 09:44 PM
heres what i came up with using torres..