(2) 18JLW6's in a Ported Box - Looking for feedback

[8Bangin 10+ year member]

Toasted the sub currently in the car so I'm moving forward with the two 18s I've had in the closet. Looking to get low and loud. Max dimensions I have to work with are 38x38x20 inches. The current plan is for a box 20 high, 20 deep, and 38 wide. (Technically 20.75 high with double baffle.) The subs will face the front or rear of the vehicle and the port will face the roof. Port tuned between 28 and 32 Hz, haven't decided yet. I want to take my time on building this enclosure and do it right as opposed to the last one which was slapped together and looks the part. Please provide design related feedback and any ideas you have as to how this could be done better.

My main concerns are the port being far enough away from the drivers and how best to brace the box. Here is a sketch of the box.

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[Jroo 10+ year member]

I would do a search on this woofer. There are several post that go back and forth about box size and should I port or go sealed. You can go ported, but the general consensus was this is really not the woofer to go ported with. JL never like the sub in a ported box and there might be some voice coil issues that some brought up by doing so. I have one and I would just go sealed, but larger than the JL specs.

 

[2RZ-FE 10+ year member]

Not recommended for ported. http://mediacdn.shopatron.com/media/mfg/9013/media_document/live_1/15_18W6_BDS.pdf?1317790201

I'd go 2cf sealed at least.

 

[Sleeklsc 5,000+ posts]

Yeah, abort ported boxes for them. Mine were in the rec size @ 1.75 each and felt they would've liked more room. 2-2.75 is what i'd plan for each.

Mine were plenty loud, but if I could go back i'd build it a little bigger.

 

[8Bangin 10+ year member]

Same dimensions and just eliminate the port? That would give roughly 3ft^3 per woofer. But I've heard when two woofers share airspace they each see about 2/3 of the total volume, effectively giving them 4ft^3 each.

Still open to ideas for bracing.

 

[wenn_du_weinst 10+ year member]

I would use same dimensions but put a center divider in between the subs. It will make sure the box is braced well enough and leaves you with a useable box should something happen to one of the subs.

 

[8Bangin 10+ year member]

Are there any disadvantages to the center divider idea? I really like that idea so long as it won't affect the deebeez.

 

[Sleeklsc 5,000+ posts]

Doubt it. If you don't want to do the divider just brace it. Either way is fine.