DB12 wrangler underseat setup, HELP!

BigDuke10

Apparently I was posting this in the wrong section of this forum so hopefully all of you can help me out. i have an older DB12 which i used to run in my jimmy and became very fond of. i am now planning on installing it under the seat of my 02 wrangler and am working to make it fit, it is going to be very close. the sub will be firing down towards the floor and i am trying to figure out how far the sub should be from the floor for optimum sound. i believe the rule is half the diameter of the voice coil? am i to assume that that is 6"? i no longer have all the specs for this sub and they seem to be hard to find. thanks to a diagram from jeepforum i think i should have about 3" from the floor. hope thats enough as i don't want to use any other sub. i also need to know how much space the sub needs to be from the back of the box. im not exactly sure what year the sub was made but I never see it anymore. i think i got it sometime around 1997 or so. its the original DB, all black with the very hard center cone. the back of the magnet says DB12 Dynamic Balance Series, 4 ohm. the sub would be firing at the floor at a slight angle.
i am using the same design as another jeeper from his website,

http://www.sirgcal.com/

look under 97-02 TJ large in seat sub enclosure. it shows his design diagram and how he installed it. i would need to use a spacer for the sub as it is another 3/4 in mounting depth and i would need close to another 1/3 of an inch so that the port behind the magnet isn't touching the back of the box. i think this is the best place for the sub as it would be hidden and save space. i also like the volume as it is almost exactly what the DB called for which i believe was .88 cubic feet. i don't want to have to buy a new sub but will have to if i can't make this work. let me know what you think and if you have any ideas or opinions. Thanks.

neomagus00

fyi, the voice coil diameter on that sub is probably 2.5"-3", not the whole 12" ...

and i dislike that design for a number of reasons, and that number is three... first, there is zero space at the back for venting of the voice coil - you need at LEAST an inch, better to have three, at the back of the sub to allow proper cooling... second, the angle could hit the magnet on the sub, but this can be approximately checked by making a scale drawing on graph paper, using accurate measurements... third, 3/4" MDF is preferred, but since you're pressed for space and that isn't a high-power sub, 5/8" should be fine...

if you can't hack up a box on your own, give me the measurements and i can try to wrangle one for you...

hehe... i made a funny... 'wrangle'... :rolleyes:

BigDuke10

huh, maybe if i went with a 10 instead of a 12 there would be a little more space?? i am also checking to see if i could raise the seat maybe as much as an inch for the extra space. i will have to do that tomorrow, i also don't want to compromise safety. anyways, what would it run me in terms of cost if i were to ask if you could try "wrangling" a box for me out of the dimensions on the SirGcal homepage?? i think if i can't make the 12 work by raising the seat and adding a spacer between the sub and the box i will look for a 10 that has a small mounting depth.

neomagus00

well, for just a design, totally free... as for building, i don't have nearly enough free time to do that this semester ...

all you have to do is pick a sub, and tell me the constraints of the system (i.e. how wide it is at the narrowest point, how the height changes from front to rear, yadda yadda...), plus how you want it to sound - within limits, i can shoot for a box with more bump or a box with more deep bass...

BigDuke10

that would be great. let me look for another sub i would be interested in using. i wouldn't be to concerned with extreme deep bass or bump. preferrably something in the middle if that would be possible, especially if i were to get a new 10. let me look into it and ill pm you when i have all the info. i appreciate it, thanks.

PoweredByDodge

<---- the DB/DX guru


and i've done many a sub downfiring...

all you want to do is make sure you've got a little extra room after max excursion. the DB's are not long throw woofers, so its not going to be a huge space... if the surround of the woofer is 2 inches from the carpet in all places, then you're fine. the key is making sure its got clearance all the way around - may floors are "curvey" or "humpy".

0.88 was the ideal for that sub, but i would say that you can go as low as 0.65, add a little extra power, and call it a day. if you like the speaker, use it...

otherwise... if you like the sound of it - but can't bear to go rigging it for your ride... then take a look at a speaker that sonically is very close to the DB's...

www.imagedynamicsusa.com --- Image Dynamics ID series Version 3 - 8" sub ... takes a 0.2 to 0.45 cubic foot enclosure --- still takes 300 watts rms though

and its CHEAP.

BigDuke10

a sub that small will sound as good?? what i was really worried about what the venting inside the box. how far does that vent on the magnet have to be from the back. cause i can get it an inch, maybe a little more but anymore and the seat is gonna be way too high. is that enought room?

neomagus00

for a 300 watt 8", i'd say so, but that'd be an absolute minimum...

PoweredByDodge

ID subs defy common beliefs about speakers... they'll do the job.

as far as the clearance for the vented pole piece... 1/2 an inch is fine ... hell i've got my seat leaning back on a pole piece vent...