S13 coupe 12" sub box designs

[jday240]

First off I searched and found 1 post about 12's in a coupe and that only discussed brand. I wanted to know if anyone had any designs for a sub enclosure for 1-12" sub that will fit the coupe's trunk area. The height of the box can be 12" max, 30" wide and depth is at least 18" due to port length. I prefer an angled box to face the front of the car but I am not sure if it is possible. Any discussion will be appreciated...I haven't had sub(s) in my car for the last 4 years and I am looking forward to it when I finish the body work on the coupe.

These are the specs:Cloth laminated paper cone with MD6 coating Dual 1 ohm voice coil Die cast aluminum basket Aluminum/chrome dust cap for extra rigidity under extreme conditions Black wrinkle finish with Diamond cut Chrome finish front & back plate Large roll treated foam surround One piece, 360º rubber gasket Dual conex spider Woven tinsel lead through spider Chrome binding post terminals 2200 Watts Power Handling 1100 Watts RMS 340 oz Magnet 4" BASV/Kapton hybrid 18AWG voice coil Ported Box: 2.4 cu ft Tuning: 40Hz Port Suze: 4" (dia) x 16.75" (length) # of ports: 2

[PoorManQ45]

...and depth is at least 18" due to port length.

Don't mind that, you can put a 90 degree elbow in the port to make it run the length of the box.

I prefer an angled box to face the front of the car but I am not sure if it is possible.

The the highest possible SPL with minimal cancellation the sub should face the back of the trunk(tailgate).

I'm sorry but I can't be of much more help then that as I haven't worked with a 240 in person.

I would recommend that you make a fiberglass enclosure. It's "fun", and a good skill to have, and your enclosure will take up as little space as possible. And best yet, it'll only weigh about 10~20 pounds, compared to an MDF box of the same air volume which will weigh about 75lbs

[onosqv]

you can fit 12's in a coupe if you angle the box at approx 45 degrees or so.

I had 2 12's in my coupe - 2 separate boxes. The boxes were relatively tiny - approx dimensions probably 12 x 14 x 14 or so. More aimed at response & quality rather than loudness I suppose. They are currently packed away in storage right now while I work on more important things, but your idea should work fine.

If you aren't planning on using your trunk for anything else (i.e. groceries, books, tools, etc), then the possibilities are endless, but yea...

My question: is there any reason you want to run ported rather than sealed? I've heard many ported boxes and most of those just sound too sloppy for my tastes.

[jday240]

Thanks for the help...I didn't know I could put an elbow on the port. As far as the design I plan to angle the the box for that reason so I can mount a 12" speaker. I am partial to a sealed box myself but want this particular speaker designed only for ported applications.

I have read the article on fiberglass and I may try to build it w/ fiberglass.

[PoorManQ45]

My question: is there any reason you want to run ported rather than sealed? I've heard many ported boxes and most of those just sound too sloppy for my tastes.

Yep, and there's the fact that most people port them around 40 or 50hz because they play stupid rap music in their cars, which all songs seem to contain a single frequency bass note(between 40~80hz), not much else.

THe problem with going with really small ported boxes is that porting them to a low frequency(~20hz) becomes extremely difficult. I don't mean it's hard to tune them to that frequency, I mean it'll be difficult to get a good response down to that frequency. You'll end up with a 3~6dB roll off down to the tuning frequency, then a spike of ~3~9dB. This makes for horrible quality. Have you ever wondered why GOOD loudspeakers(with built in subs?) are so large? To partially get rid of the problem I'm talking of, and to increase the efficiency(larger boxes are usually more efficient).

Just for a quick test, use WinISD Pro to model a sub of your choice in a ported box. One box should be the recommended size(probably between 0.5 and 2ft^3), then model that same sub in a "large"(5~15ft^3) box, both tuned to the same frequency(should be around or below 30hz). I'll bet you $1 that the larger enclosure has a MUCH smoother response down to the tuning frequency.

I absolutely HATE it when people build subwoofer boxes and then tune them to 40~50hz. It's an effing subwoofer for god's sake. It's Supposed to play down to at LEAST 20hz. And one of the MAIN reasons for a ported box is to extend the lowest frequency that the sub can play. 40~50hz is right in th emiddle of a SEALed box's tuning frequency. If you want to capitalize this section of the frequency range then please go with a sealed box. If you're going ported, go lower

*edit* yesterday there was this car behind us that had a sub or two. It was absolutely horrid. They only played one freaking freqeuncy. It may have just been the song(probably rap), but it sounded like a$$