View Full Version : two Audioque 12" SDC port box help

03-16-2009, 11:49 PM
I have two 12" Audioque sdc2.5 subs going into a slot vented box. Im just wondering how to get the best sound out of them. I listen to alot of drum n bass music, and rap.

So what hz should the box be tuned for?

also, with this tuning, would it still bump enough for competitions?

or should I build 2 boxes.

Ive got space, if i remove my rear seat ill have more, but the space I have now in a civic hatchback is..

19" high to sit flush with hatch glass
29" wide
and 19" from hatch to rear seat.

also, should I face subs up and port rear? or whats the best way??? Subs facing the rear along with the ports?

03-17-2009, 12:58 AM
Let's see if I can't help you out buddy.

I, like you, listen to a lot of electro. Alot of breaks, D&B, trance, rock, metal, and just about everything in between.

If you use that regular slot ported box, you will hate yourself for doing so. The group delay you will get with a ported box is REALLY hard to avoid when it comes to fast changing frequencies. I know this, because I have been through 13 different setups of subs in the last year to try and get it right. The closest you will come to getting what you want, is building a completely KERFED box. That is where all of the corners are rounded off by bending the wood. Do a search on it if you don't know what I'm talking about. I still have mine I used before this current setup and the group delay was "almost" non-existent. But if you're like me, you'll still slightly notice.

I finally said fvck it, and went with the most cone area I could SEALED and as much power as possible with my electrical. I run 4 RD Sonance 12" in a 5.9 cu. box with, come Wednesday, 4000 watts. The SQ is on point, no blending of responsive frequencies, and it's damm loud. You have what most have said around here to be one of the loudest cars there is. This is in the trunk of my CLK.

So...what do you want out of your sound?

The AQs that you have usually like higher tuned boxes (34-36 hz). A 4-4.5 cu. box would be sufficient. How to face 'em...I've never owned a hatch. Plenty of guys around here have and hopefully will chime in.

03-17-2009, 01:21 AM
face it all to the back, it will just bounce off the hatch and sound nice.

03-17-2009, 02:33 AM
I'd do 4cubes @ 36-38Hz with 64^2 of port area. My HDC's have NO trouble keeping up with fast double kicks, etc....

03-17-2009, 02:49 AM
You say I'm going to have one of the loudest systems around? or loudest car because its a civic hatchback?

also with my dimensions I would have to remove the rear seat to get the additional space, wouldn't I? Would I be able to get 4 cubes in the space allotted? I think ill have to mount my amp on the rear seat cushion or under it.

and to get more room idk how I'd do it, i have this lump that comes up for the rear seat to bolt thru in the middle. youll see it in the pictures of my sound deadened car :)...

and that kerfed box just looks too hard to **** with.

03-17-2009, 02:52 AM







^^^lump is right there right at the edge of the left side

Im thinking of maybe mounting a battery where the spare tire goes?? or maybe the amp?

03-17-2009, 02:57 AM
whatchu guys think?

03-17-2009, 03:52 PM
wow I post all these nice pictures, and I get no feedback lol

03-17-2009, 03:57 PM
What kind of deadener is that?

You could always cut that hump off where the spare would be bolted to, but...or...you could just build your box with a lip that would sit on top of it.

I'm not saying you'll have the loudest around, but what do YOU want out of it? Do you want as loud as possible or do you want it to be loud and be accurate. D&B is NOT the same as it would be considering double kicks when it comes to rock music. You should know that. Fast changing bass frequencies will soon blend together when your listening to it. Drives me crazy!

03-17-2009, 04:06 PM
i've got a focus hatch, I cut out the hump in my spare tire well and used it to hold my battery. I also removed my rear seats b/c it's hard as hell to fit anyone back there anyways. my box is 9 cubes for 2 15s and it's only as high as the original back seat. you'd be much happier removing those back seats. btw my box is tuned to 38 hz and the port is right behind the head of the listeners. mine isn't the loudest but just imagine listening to you system with your head 1ft infront of the port.

03-17-2009, 04:18 PM
I want my **** to be loud. loud is good. thats why im spending a chunk of cash on big amp, bat, and decent subs. I dont want a sealed box. I want to be able to tune the ports.

also, i wasnt talking about the spare tire hump, i was talking about the rear seat bracket. its visible in the bottom left of the picture. I dont wnat to cut it off, because if i ever sell my car, what do i do

I think I will remove my rear seats, but leave teh seat cushion attached. If that makes sense. If i remove it there would be a "step down" and that wouldnt make my box lay flat, im assuming. Plus my fuel pump is under there too. And your right, there is NO room for people in the rear seat, so i might as well remove it. I do have a cargo cover, I just hope thatll be enough to cover most of the box..so people cant see it from outside.

right now I only have my rear windows tinted. I dont have teh hatch window or front windows tinted :hide:

and also the deadener was peel and seal. it was used to drain out some of the sound from my exhaust

03-18-2009, 04:57 PM
how do i make it 4.5 @38 and make it over that hump that the rear seat bracket in the middle of the floor is....not the hump in the hatch/spare tire area...

box width : 29"
height : 19"
box depth: 19"
port width : 3.8 [that will give me 36hz then become 38hz when i mount the subs?

wood thickness = .75
square port height = 17.5
square port width = 3.7
square port length = 14.55
square port length 2 =8
total port length=28.85
square port diameter =9.07977...etc
square port area= 64.75
square port volume internal : =1868.0375
square port volume displaced= 1884.3875
box volume =3.783
tuned freq= 36.039

thats with a port on the left side only, and the subs will be two audioque 12" sdc's

but thats not 4.5. so i gotta find a way to get around that bracket

03-18-2009, 05:14 PM
4cubes, not 4.5 and tune to 38-40Hz with 64^2 of port area. Port should be 16-18" long, longer will tune lower.

Gotta figure out how to make the box fit...

03-18-2009, 05:30 PM
everyone is telling me 4.5 for the AQ 12's. they are the sdc2.5's

03-18-2009, 06:02 PM
owner of aq told me that shits too big [4.5]

03-18-2009, 06:09 PM
owner of aq told me that shits too big [4.5]

I didn't tell you it was too big I told you it was a little on the big side but would work fine. It will work a little better in about 4.2 net but you won't be able to notice it by ear.

03-18-2009, 06:16 PM
so build it for 4.2? I just dont know how to get it over the rear seat bracket...can anyone help me with that? because if it goes taller than 19" itll hit the cargo cover, so if i made a podium for the box to clear the rear bracket, id have to make it shorter right?