Nore474

I am going to replace my sealed box with 2 MA audio XL 12's into a ported box with them

I have to make the box volume 2 cubic feet for each sub how does this sound
lentgh 41"
hieght 18"
witdh 14"

I am not to sure where i should place the Ports?

I have those black prefab ports with a 4" diameter and the port lenth is 6" i am pretty sure that is to short I think i need it to be 10" I can make that longer by just putting pvc pipe over it right? or should i just use pvc pipe?

This box should fit into my maxima right?
can you guys give me some pointers!!! please

thanks!!!

Soul Fly

volume = LxWxH
1 cu. ft = 1728"...(12x12x12)

I think thats a little odd - are you going to have a labryinth/separator in the middle of the box? (to make it 2 separate enclosures?)

hrygeek

What size MDF are you using? 5/8" or 3/4? Either way you are well over 5.5 cu ft. What are you trying to tune the box to? A 6" long port by 4" is not tune very low. Prob around 50 or so HZ. As far as the box fitting is should be fine. If you give me the specs on the subs and what you want the box tuned to, I can tell you how long to make the ports. Need more info. You can use PVC or go with square/rectangle ports.

MaxSE03

iTrader: (1)

Here is one for port size, number, length, tuning fq: Port size

Here is one for box volume: Enclosure

Hope that helps.

Nore474

I appreciate the help guys

I am going to use 3/4 inch thick mdf

I need an enclosure thats 2 cubic feet for each sub that will fit into my maxima.

my subs are the MA120XL

MA Audio Sub 12" 600 watts and 1200 watss Max
Dual 4 Ohm Voice Coils
240 oz. Double Stacked Magnet
Sensitivity: 84.8 dB @ 1w/1m
Mounting Depth: 6.25"
Port size: 2-4" (d) x 14.75" (I)
Sealed Box: 1.0 to 1.4 Cu. Ft.
Features
Patented Die-Cast Chrome Plated Basket
2" Treated Foam Surround
Heavy Duty Non-Pressed Paper Cone
Patented Thermo-Cooling Motor Structure
Dual 4-Ohm Voice Coils So it plays at 2-Ohm or 6-ohm

Nore474

what do u mean by tuning frequency

MaxSE03

iTrader: (1)

Tuning Frequency

This is the best i could come up with right now. I don't have any good favorites on my work computer.

Nore474

i would like a 29-33 tuning frequency

ok I took measures of my trunk....

On the opening where the trunk flips up the smallest length measurement was 40 inches inside the trunk the lenth was approximetly 50" the height is 18"

Can you guys give me an estimate on what I should make my box to achieve the 2 cubic feet for each sub I have 2 subs

I am going to move my spear tire and trace the rug of the trunk onto a piece of ply wood. Will the piece of ply wood just fit into the trunk or do I have to make it into seperate piece?

Where do you guys with big boxes put them? in the back more or in the front of the trunk?

and I still have to figure out where i want to put my amp I was going to make it flush with the piece of plywood that I was using as the floor of the trunk.


Thanks for all the help I really really Appreciate it!

Nore474

also when i make the box do i need to put a seperator in the middle to make it into 2 seperate enclosureS?

Nore474

ok I took some measurements from my old box to see how everything fits....

How do these measurements sound inside the trunk of a 4th Gen Maxima

W=41" H=14 Depth= 17

I am a little shady on the depth

these measurements come out to 2.13 cubic feet in each enclosure

hrygeek

Keep in mind when you are calculating the internal box size that you also incorporate in all of your calculations the space taken up by any bracing materials (divider/brace), the speaker itself, and the port/s. The dimensions of 41" X 14" X 17" are fine. Your port length is kind of deep. Also keep in mind that the ports should not be placed on the back, bottom, or sides of the enclosure. The port should have a minimum of 4" from the speaker and any wall/bottom. With a 17" depth that will be impossible unless you come out of the box a couple of inches. You can also calculate a rectangle port for the same purpose. If you vent straight up, you need about 4" from the port to any obstacle. I need the xmax of your drivers in order to calculate frequency of the enclosure.

If you are going to flush mount the amps, be sure to leave breathing room around the cooling fins.

If you are going to put in a piece of mdf on the bottom of the trunk, make sure your measurements (H) will fit. 3/4" mdf and a 1/2" of carpet will reduce how tall the enclosure can be.


maxima.cardomain.com/member_pages/show_image.pl?image=member_img_a/236000-236999/236421_55_full.jpg

Nore474

I am pretty sure the max wattage of my speakers are 1200

and I got the height covered.

I am gonna mke the ports on the front of the box with the subs is that a good idea?

so the volume space is 21" and the subs require 2'so with the brace it should be good. and I am still confused about the ports they have to be 18.8 inches accoreding to that Enclosure link above I want them at a 30 tuning frequency
so with the ports will it make a difference if I use elbows and put them on an angle like this ( |_ ) ? will the ports still have the same effectiveness?

hrygeek

Making an angle in a port is fine. Also having the ports and the subs face the same way is fine.

Dustyroads

I responded to your post over on MaximaForum. Here's the info I gave.....

Internal box dimensions....

39" Wide
17" High
11" Deep

If you use the 2 4" ports at the 6" length then your tuning frequency would be 42Hz, here is a plot of the frequency response.

Nore474

does it matter how close the ports are to the sub if they are on the same side of wood?

how do u get the ports to be sturdy enought and to make them stay put?

Nore474

i made it 38x18x14 and it comes out til like 2.1 interior space

I got a 4" diameter port by 12.5 to equal 35Hz

how do u think this will sound guys?

Soul Fly

1728x2 = ????

Dustyroads

Tuning the port that low is kind of dangerous, you are getting close to the Fs of the speaker. If you tune at or below the Fs of the speaker you can damage it. Since you already have 4" ports that are 6" long, then just tune the box to 42Hz. It will work out real nice for you.

There is no spacing requirement for the ports, but I would leave some room between everything for support.

Nore474

no i used 4" ports that are 12.5 inches long!

thats like 35Hz i think

Nore474

the verdict...


wow it kicks amazing

its loud as hell but to many rattles how can i get the rattle out of the trunk where the M A X I M A emblems are?

hrygeek

Dynamat as much as you can. We used expansion foam in the deck lid and then dynamat over it. Be careful around the locking mechanism. Ours got a little sticky.

Nore474

how much will that dynomat and foam cost?

hrygeek

Expansion foam is about 4 bucks a can. Dynamat extreme on ebay is about $100 for a trunk kit. You can also use rolled asphalt ($10) from home depot/lowe's. A LOT cheaper and works ok. When you put expansion foam in the trunk lid, be sure to watch out for any mechanisms that might get stuck. If in doubt, don't put expansion foam in certain places. Once you foam it, place tape over the holes. Otherwise it will make a huge mess. I have also heard of people using the roll on bedliner stuff for dampening. Don't know. Haven't tried that one yet. That's about $50 a can from the local auto parts store.

http://maxima.cardomain.com/id/2k2kevpearlse

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Nore474

hey where are you from hrygeek? I appreciate the help before you gave me

jmax

Is this an old thread or something? Because I don't see where anything taller that the rear deck will fit in the trunk. What is the year of hte maxima you plan to put this in? And no offense but dustyroads is way off the truth. Tuning too high is what allows a lot of subs to overexcur and turn into rubbish.

hrygeek

Phoenix, AZ. No problem on the help.

Nore474

when you say trunk lid thats the part on the trunk behind where the key whole is?

hrygeek

Yes. You can dynamat/asphalt that whole area. DON'T put spray foam anywhere near this area. It will clog up the locking mechanism. Put foam on the flat part. Dynamat/ashpalt over that.

http://maxima.cardomain.com/id/2k2kevpearlse

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