New box design for a 13w7

[Lite-On]

Hi all,

I'm currently busy with a new build in my '63 Pontiac. I'm starting with moving the 6,5" to the front, but after that i'm going to make a new box which I would like to place under the parcel shelf.

I have a lot of unused space right there, and would like to keep space in my trunk - so I thought..... why not building a box under the parcel shelf, and seal it off from the trunk :-)

The sub i'm using is a JL 13w7. I don't want to discuss on this sub, as i'm quite happy with it

Well, i'm still not sure what kind of box i'm going to use. I would like to have decent SQ - it doesn't need to get stupid loud, but it would be great if it could by a ESPL setup or something like that.

For now i'm powering the sub with only 400 to 500 wRMS - I know it's quite low, but that will do it for now.

I'm now playing with a standard ported box (JL specs) dropped in the trunk, but I don't like how it's playing the lows in my car. This box is tuned around 35Hz.

With my new box i'm looking for something that plays the lows a bit better, but it also needs to do play the higher end (like 40Hz). Not sure if that's possible, but i'm going to give it a try, as I play all kind of music (rap, top40, chillout/lounge, drum 'n bass, dubstep, metal etc.). I like to have clean bass with all kinds of music.

A T-Line will become to big... that's something I already know. But i'm also thinking about doing a 4th order bandpass, ported through the rear seat.

But the big question with a 4th order is..... will ~ 160 liters (5.7 cuft) of space be enough do to a simple 4th order which is ported through the rear seat?

With a sealed box I think i'm going to loose a lot of output power isn't it?

[teamace24]

Dont be ashamed to to talk about that sub, it really is an amazing sounding sub and can get very loud in the right box. I love those subs, many people talk crap about them only because they are expensive, and they are, but to say they dont sound great is so not true.

I had the 12 inch version in a 2.5 cubed net box and it slammed every kind of music i gave it from lows to upper lows, sounded amazing as well. Had it on 1000rms.

Put the 13 in about 3-3.5 cubes net ported. Tuned to 34hz and you will love it. JL really works great in big boxes.

[Lite-On]

Thanks for your reply :-)

So you had good experience with the W7's? Atm my box (around 70L), is in the trunk, nothing special but it doesn't hit the lower lows (<30Hz). So with chopped and screwed, the sub has tons tons of excursion but there is almost no sound in the cabin, that's the reason why I have mixed feelings with a ported design. I never tried a larger box like 3.5 cubes on this sub.

But i'm sure that it will sound completely different when the sub is under the parcel shelf, and completely sealed off so no sound can leak to the trunk.

I'm still thinking about doing a new ported build, or bandpass - but I don't think I have the space for a bandpass. I would like to hide the box under the parcel shelf, ported through the rear seat or ported in the parcel shelf. I'm having around ~6 cubes of unused space, so in case I go with a ported design... space isn't an issue.

Did you ever tried other designs on w7's, like the 4th order bandpass?

If I go ported - what kind of port would you recommend? With a ported design, i'm thinking to do 2 round ports mounted in the parcel shelf. How large do I need to make the port(s) in order to let it move lots of air :-)

[teamace24]

Have some one on here make you a design that specializes in making them.

2.5 Cubes net even 3 if you want. Give it 1000rms and tune to 33-35hz. Good port area 14-16 and it will pound very loud and low.

Experiment with sub placement in your car and make sure you set your filters properly everywhere so you wont lose the 25 plus hz bass lines.

[8ight]

teamace has got it right about JL subs in larger boxes, W7s get nasty loud AND low with some box volume.