box for 2 15" volfenhags

ok i just got 2 15" volfenhags. i kno they aint nuttin special but i got them real cheap, plus im not expecting to hit hard i just got them for looks (so dont fill up this topic with how much they suk and laughter). i was wondering if anyone can help me out with what kinda of box i should build and what specs for it. i kno nuttin about buildin boxes ,ive always bought prefab ones till i heard that the best boxes are built and not bought built.

id really apreciate the help.

its going into a 98 jimmy. the subs came with a volfenhag amp (the amp is max power 1600w, 2 ohms 640w, 4 ohms 440w, 4 ohms bridged 640w).here are some specs ive gotton for the subs online (from the volfenhag site)

fs29 Hz  

qts0.670

qes0.806

qms3.964

VAS:116L

efficiency (1W/1M):91db

piston surface area:0.0855m

RE DC RESISTANCE 3.2 OHM

dc aesistance: 4ohm

dual 4ohm nominal impedace

mounting depth 187mm

RE DC RESISTANCE 3.2 OHM

id like to use a ported box but i was reading something that said if the qts was higher then 0.4 its better to use a sealed (it was on this site where i read it)

mounting diameter 360mm

and the rms is "600w"

and the amps a 2 channel

(again thanks alot)

You are right, chittyboom, and good job doing your research.  Put those in sealed enclosures.  Measure the back area of the Jimmy and decide how much space you want to allow for use of a sub box.  The larger amount of space you can give up the better, and build the enclosure to be rigid with internal bracing.  At least 3 cu. ft per sub so you're going to be building a very large box.  You could also build two boxes and set them side by side facing the rear (for easier manuevering and removal).

If you can't give up that much room, just make it as large as you can.  Separate the chambers so that each sub has its own, and the separating baffle will act as an internal brace in itself.  See other posts on this forum about building boxes.  You can even mount those subs inverted if you want to show their backsides.  Have fun and good luck with the building project and don't look again at any prefab boxes, which will all be too small for your needs anyway.

Get that much of it done and report back to the forum if you want any help with the sub coil wiring and wiring to the amp.

damn u guys are good. this is the best car audio forum. anywhere else and theyll knock on you for any reason.

ok so basicly the bigger the box the better it sounds? but it has to be atleast 3cu.ft.  i think ill take ur advise and build the 2 seperate boxes so i can change it up now and then (both together or apart). as for the bracing (i read this somewhere on here) i get a 3 inch block cut it in half so its a triangle and put it in every corner?

and what would u recommend for the wiring?

....Actually.....you could fill up the whole Jimmy if you wanted to!  Looking at it in WinISD I wouldn't accept the response if each enclosure wasn't over 2.5 cu ft.  But in a vehicle there is always a compromise, so for these 15's 3 cu ft interior each is a good way to go and you won't have to beef up the suspension to carry the load.  Don't worry about it being to the inch to what I suggested, but do make both enclosures the same volume.

These woofers are efficient, so you'll get enough power to them with what you have, and the larger size enclosures will help with that efficiency too.  The subs are DVC 4 ohm according to the specs you listed so you will wire each sub's coils in series.  Then the two subs will be connected together in parallel.  The one set of speaker wires that will result from this wiring will go to the marked pos and neg terminals on the amp for a bridged setup.  Looks like this:

Your idea for bracing will work.  Bracing is best accomplished by trying to find the closest place to the center of an expanse and putting a solid object between one baffle and the opposite baffle.  Some people will use a solid sheet of MDF and cut a large hole in the center;  others will cut that whole piece of MDF so that it looks like a cross.  Others use the wedges in the corners.  I like using the cross best because it applies stability at the very center of an expanse where flexing is apt to happen the most.

Glad you see that this is a great car audio forum.  My way of thinking about someone's equipment mirrors the general philosophy of this forum:  there are two or three considerations.  One, when someone posts asking about certain brands' reputations in order to make a buying decision.  Two, when someone posts with a close-minded attitude about their brand of choice and pushes it on everyone.  And three, when someone posts, like you have, with equipment already purchased and is asking for installation help.  The first deserves to have knowledgable people point out the shortcomings that have been proven with the gear in question so that a good choice can be made.  The second sometimes becomes a nuisance after awhile and has to be put down like a lame horse.  As for the third...hey, the gear's in hand and going to be used so let's make it work the best it can be!

Always start out your box-building project by making sketches on paper.  This would be a sketch of the bottom of a proposed enclosure if I wanted to double-baffle the front:

Start with one of the sides of the box;  the bottom, being the foundation, is a good one to start with.  The sketch above would represent the bottom and would be as large as the limits of the exterior.  That is to say, the box won't be any bigger than this in any direction except up.  The side walls are shown as setting atop the bottom panel and their widths are shown for clarity in figuring true dimensions...much better than drawing simple lines for walls. 

The sketch would be labelled "bottom" and the side with the double baffle would be labelled "front".  Knowing that you are using 3/4" baffles, you know that the front will take up 1 1/2" of space and each of the other sides will take up 3/4" of space.  This sketch will give you two of the three dimensions you need for figuring cubic inches/feet.  Once you have another sketch done showing the side (or front/back) wall which will give you the third dimension of height, you will have the three dimensions length X width X height.  Just start out like that and put in all the proposed measurements inside and outside.  Draw in all support baffles and figure their cubic inches separately by using additional sketches.  Have it all laid out and checked over at least 20 times before you plug in the saw.

alright guys thanks for all the help u guys have givin, everythings already built , installed and thumping. the actually subs are pretty good , i was expecting worst, but the hit harder then when i had my 5 shhhty 12s. everythings good so far , no over heating , nuttin wierd. id give the setup a 6.5 lol