hey everyone, i have changed my mind again...since i am taking a wood shop this year i have the choice to build a subwoofer enclosure. i have been talking to a few techs around here and have come up with the desision to do 8 12" SRW1285 sealed. anywyas i geuss my question is....do i have to know anything special to do with this box, i know i will need to brace it and seal it very well, but do i need to double up all the walls or double anything, is there any tricks to a box this big sealed?...is it just not a good idea...looking for any input to help me, by the way, this will be going in a 1994 extended suburban....thanx in advance...

can you post the design? make sure you have alot of bracing and as air tight as possable.

In one big box, try to make each woofer in it's own chamber, avoid sharp corners in each chamber. Brace each sub's magnet to the rear of the box (measure 3 times, cut once), avoid blocking any woofer vent holes.(tight bass)
Use T-nuts to screw the subs into the cabinet.(tough with MDF)
Use different thicknesses of MDF or Particle board (k3).(avoids cabinet resonance)
Use proper terminals in the cabinet to connect the woofers(no holes with silicone) .
Stuff each chamber the same amount..,FULL.

ok, new question....would this be better ported or sealed....since there will be som much preassure in the box would ported mabey be a better route to go to expell the preassure....this will be the first box that i actually build myslef im am no vetran wat so ever, http://memimage.cardomain.net/member...50_13_full.gif theres a pic of the ported design...kind of crappy but i hope it helps...thanx a lot

on a box that size you are going to need as much bracing as possable.if your going to go ported try keeping the subs and port on the same face.

I'd say stay sealed.., but everyone's got an opinion..,right Dukk?
Ideally a ported cabinet would have the port on the same "plane"(side") as the woofer, and located half the diameter of the woofer ,away from the cone and any cabinet walls.(so if an 8in woofer, the port should be 4 inches from the edge of the cone, and 4 inches away from any cabinet wall)
Having said that and keeping in mind the term "ideally", unfortunatly a car is NOT an ideal place for sound.
If you have the power, stay sealed, if you want SQ.
As for the drawing, imagine 8 chambers making the whole box, each chamber will act as a brace.

If you are going to go ported for SPL, it is all a matter of test and tune.

And never have I seen a port more than "half the diameter of the woofer ,away from the cone and any cabinet walls.". Usually when running a slot port, the one side of the slot is the box wall. [img]graemlins/thumb.gif[/img]

As loud as Mat plays his music in town I am guessing he is not out to build a pure SQ type install with this vehicle.
I'm guessing a loud daily driver that still sounds good but can do decent numbers on the mic.

I would definitely suggest a ported design.
Maybe consider going for a bit better quality sub and try four 12's/15's ported.

I would wager that four RE SE 15's (or similar) ported would destroy the eight base Clarion 12's sealed in terms of both output and retain better SQ

Just a suggestion.

hey man....thnx for the advice, yea i know these subs arnt the greatest but i already got 4, and im on a really low budget...so this is wat im doing thios year....i still have to decide...the sealed is still sounding pretty good....so ur saying if i just make one box but seal each chamber off completely, seal it very well, and fill it it should be fine? do i need to double any sides up or anything, thnx again

You're not likely going to be able to get enough volume to port those subs in a Firebird.
Stay with the sealed design and give em 1/2 a watt less than what blows em.