Ok, So I talked to Atrend designs, they make good quality and very reasonable subwoofer enclosures.
I currently removed my 8" freeair's and i have a box in the trunk which is horrible rattle but good bass .

Atrend is asking me if I have some dimensions so my question
1. Should i use the slant from back seat (Since its not foldable) and use that contour to build a box that just uses that space or.
2. Have a floating design right below the Sub opening for a slim box or
3. use the backseat contour but have some sort of cylindrical design that pushes the sub close to the factory opening

I know bass is non directional but really curious. Also, BTW if i give them dimensions they can make more if others are interested .

Ram

 

Personally, I would be looking at having a custom single reflex box made where the port for the box is located at the old sub opening. This will port the sound into the cab and let you use a box with a slant on the front to follow the contour of the rear seat. THis will maximize your trunk space. If you need me to be a bit more specific, let me know. I used to build single reflex boxes all the time and if done right, can really improve the bass in both quality and sound.

 

yes please i looked up the single reflex but I cannot visualize your suggestion. Thanks for the help

 

ramandanu, picture a typical sub box that is one big box (leave out the hole for the speaker at this point). Now, divide the box into 2 equal volumes (ie, divider in the middle). In that divider is where the speaker is going to get mounted. This will result in the speaker firing into a box that is sealed (this is good for tight bass notes and not a lot of wobble that can be associated with other style boxes) and the back side of the speaker will have a tuned port placed in it (this port improves the efficiency of the speaker and therefore you get more dB/volume out of the speaker for a given amount of power input.

You can also do the same thing using 2 subwoofers where you take the same box but you divide it into quarters (ie, install 3 dividers). Remove the middle most divider (this will leave you with 2 boxes on the outside and a box that is twice the size in the center). The subs will then get installed into the dividers like before with the speakers firing into the double size box and the outer boxes will have the tuned ports placed in them to give you the volume.

The big trick with this style of box is knowing what size port to install. You get the wrong size port based on the specs of your speakers and you can actually make a speaker that will be very quiet.

Like the below article states, you may have also heard these referred to a "bandpass enclosures". If you want some reading, read this: JL Audio » header » Support » Tutorials » Tutorial: Bandpass Enclosure Characteristics

 

cool. Thanks! So I read it up and makes sense. So Atrend is asking me for dimensions so they can have a product for XJ. I might give them the port openings, the back slant angle space etc and tell them to figure out how to set up the port. I plan to use a single kicker solo baric L7 10". will keep this DL posted if I succeed

 

ramandanu, if you were near me in Washington DC, I would tell you to come on over and we can build it right in my garage. IT is not that hard to do and with a few equations, you can figure out everything.

 

oh. I went to George mason and lived in Fairfax a long time. I miss DC


I will check online for some equations. If I am successful I can share what I did with others

 

ok. here is a rough diagram. does this sound like how i should visualize it? assuming the slant goes behind the back seat and the overall bandpass port spans approximately the two ports where the 8" was before.. if so then all i need is equations for my L5 10" solobaric I plan to use

 

Aftermarket subwoofer boxes are the best option for sound quality and price. If you want to build your own, first check out this article on how to build a subwoofer box. It gives good tips to building a subwoofer box. The best way to build a cheap subwoofer box is to use a wood that is harder than the rest of the wood in the car. Some people use the trunk deck, which is made of a very hard wood. This really helps to prevent feedback and rattling. You can build a subwoofer box very cheaply by purchasing 3/4" MDF board and cutting it yourself. That can save a lot of money. You can also buy a premade subwoofer box from a local store, usually for very cheap. Doing research and asking around can also help you to find a cheaper box. Subwoofer boxes can be very expensive. The Woodstore sells quality boxes for cheap, but other stores and custom shops can be very expensive for subwoofer boxes. Sub boxes are the most expensive thing to install in jdm cars, so it makes sense to do it yourself. It is also the best way to get the subwoofer to sound the best.