Box Help

[Fors]

So I traded my s-10 in on a blue SS and the first ironic thing I did was lose sub space while keeping functionality so I'm selling my 15" fi bl and most lilely going to purchase 2 12" fi ssd's. I'm not a fan of sealed boxes what so ever so Ive been doing some searching and cant find an instance where anyone has put 2 12s in a ported box under the rear seat, 4 10's but not 2 12's. So my question is has anyone here attempted this? Ive seen forward facing boxes that give a good amount of air space ( 2.9 cubic ft ) and was wondering if it was possible to make one with a round port in it because with the calculators ive used to calculate a port it says Id only need a 3 inch diameter peice of pvc pipe thats a lil less than 4 inches long to tune it to where the subs need to be so I dont see how it wouldnt work if someone could enlighten me.

[fox_forma]

two twelves ported under our seats would be almost impossible to do and still have them sound good or reach full potential. Your best bet is to go with one twelve and use 2+ft3 airspace available under the seat and port it based on that. If you go to caraudio .com and search around for silverado projects there is a guy that did one twelve ported and it flexes everything in his truck. I am also in the process of building a single twelve box ported with overall 2.2cuft tuned to 32hz. This was after researching ported set-ups for hours in our trucks and this is really the only ported option that seems logical.

[Fors]

So even if I managed to get the min port rec of 3.4 under there it still wouldnt sound right? The pre fab I found has 2.84 cb foot and Im sure If I made itmyself I could change the back end of it a little bit and have it go behind the rear seat to get the other .7 foot of air I needed but it would require me to find a new spot for the amps to go besides on the box itself and I dont want to drill them in to the back wall behind the seat.

[paulguy]

So even if I managed to get the min port rec of 3.4 under there it still wouldnt sound right? The pre fab I found has 2.84 cb foot and Im sure If I made itmyself I could change the back end of it a little bit and have it go behind the rear seat to get the other .7 foot of air I needed but it would require me to find a new spot for the amps to go besides on the box itself and I dont want to drill them in to the back wall behind the seat.

Do you have any info on this 2.84ft box? Cuz I call bs. Pretty tough to get that kind of air space under the back seat.

Under the seat is about 8.5 " high, and about 58" long. you can go back about 16" if you stretch it and the back is only about 7" high. The box should be built with 3/4" MDF. So take off 1.5" of the dimensions, then minus bracing, minus the hump, minus driver volume. Ya, your lucky to get 2ft of airspace. Prefab boxes alot of the time use thinner wood(I've seen 1/4") so they could get more volume that way. But thats also why prefab boxes sound like...prefab boxes.

But I could be wrong...it happened once.

Do yourself a favor, take that notion of a ported box and through it out the window, it's just not feasible in these trucks, unless you take out the back seat. Ported boxes require room, and pretty tough to get away from port noise when the port is so close to your head.

I've built a hundred boxes for these trucks, done one ported box and it wasn't worth it. I'll never do another one.

 

IMO, If you want descent sounding bass, put two downfiring 10's or 12's under the seat.

I started building another box for my truck this week, and I'll do a how-to. If your interested in something like that, it might help.

 

You don't have to drill into the back of the cab. Silicone some wood behind there to the back wall and mount the amps to it. There isn't anywhere else to put them.

[Fors]

Didn't think about the thickness of the wood, its not 3/4" but its 5/8. http://caraudiofactory.com/992006-chevy-extended-p-43.html Tutorial sounds nice, I was about to go to lowes for some wood today.

[paulguy]

Didn't think about the thickness of the wood, its not 3/4" but its 5/8. http://caraudiofactory.com/992006-chevy-extended-p-43.html Tutorial sounds nice, I was about to go to lowes for some wood today.

OK, I see how they are getting a little extra airspace, the box sticks out in front of the box...yuck.

I got kids and my subs would be smashed in the first day.

 

A downfiring box is alot easier to build then that 'in front of the seat box'. That box has alot of angles which suck to do and thats also more seems to fail. The most efficient box design is square, so the downfiring should sound better, even though it's smaller. And the subs can load up on the floor.

 

I cut some wood yesterday, but i can't find my box specs, I have a notepad that I write all my specs in. So I guess I'm starting from scratch. Crap.

I do some more day and take picks.

[Fors]

what do you mean can load up on the floor? The excursion rate I think its called of the subs is upwards of 3 inches, whether they can do that in a sealed box or not Im not sure.

[paulguy]

what do you mean can load up on the floor? The excursion rate I think its called of the subs is upwards of 3 inches, whether they can do that in a sealed box or not Im not sure.

Loading up a sub is hard to explain. Bass sound waves are very long, thats why it's hard to get bass out off a truck cab...too small.

Kinda like in a car, if you mount the subs facing backwards, it's usually louder.