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View Full Version : 4 15" AQ box help, few different designs n port options, port forward suv?



WOT
07-27-2008, 04:44 PM
After checking out my car a bit more and taking rough measurements and doing some r&d bs with my current setup I think Im gonna buy 2 more AQ SDC 2.5 15's and go for 4 15" ported. But Im tight for air space, I think I'll get something like 14 cubes net total if I go with the oddshape box and go pretty close to the back of my rear seat.

I have some port questions though. Im currently running the 2 15's @ 38 hz and its port up sub back, which works great and hits hard, but the box is a cube so I rolled it over and went sub forward port up, and it was exactly the same almost identical, the port up may have been a little louder. But what I wana do is put it subs BACK and port PREFERABLY forward (toward head). Possiby with PVC ports. slong the top of the box above the rear heat.

Here a few pix that explain it alot better, see what I mean about making an odd shaped rear wall to get the most space out of my trunk..... harder to build but I need all the space I can get, dad might give me a hand with the angles.

http://img292.imageshack.us/img292/8189/portupjw0.jpg
http://img292.imageshack.us/img292/7686/portforwardslotwf0.jpg
http://img155.imageshack.us/img155/3787/portforwardpvces5.jpg

So the tops of the port forward boxes would look like this. Side by side labelled

Slot Forward
http://img155.imageshack.us/img155/1344/slotforwardviewpr4.jpg

PVC Ported
http://img292.imageshack.us/img292/5654/slotforwardview2si8.jpg

I dont know anything about using PVC for prots so Im gonna have to reasearch, but I dont think HUGE aeroports like Im gonna need is gonna be in my budget at all when 8-12" PVC would be good for this daily driver.

I dont have any cubic feet numbers so I dont know exactly how big these ports have to be. I think Im gonna have roughly 14 cubes net though, and the AQ SDc 2.5's will be fine on 12sq/in per cube per sub. But theres different measurements to get lenght and diameter with pvc ports right? Anyone have a link? Gonna have to research that.

Just trying to gauge which setup I should be leaning towards....

opinions please

WOT
07-28-2008, 11:20 AM
bump it, need advice, taking out my old box today and figuring out exactly how much room ive got

wu501
07-28-2008, 11:28 AM
don't care for the box design.

Use this port calculator:

http://www.psp-inc.com/

Chad McCan
07-28-2008, 11:44 AM
I wouldn't have the port at the top of the back seats. I'd put it at the bottom. It's going to be obnoxious blowing on peoples head. If you want to see something from the front, put a plexi panel so you can see in the box. I'd do whatever is easiest for you. If it's a slot port, do that, if you have round ports and way to cut nice holes, do that.

WOT
07-28-2008, 02:02 PM
Well I just worked it out and Ive got 17 cubic feet roughly internal

Im thinking a slot port UP towards the roof might be the best idea since there will be a few inches gap between the roof and the port at that point and not much room behind the seats if I were to put it at the bottom of the box

I'll sketch up a drawing

skateboardkid
07-28-2008, 02:13 PM
What about 4 subs firing forward with a slot port down the drivers side, SPL wall style? You might have the height x width to do so.

I think you might need more than a few inches above the port to achieve best sound at least as much clearance as the port is wide... Just so its not restricted.

The slot port might be the easiest to construct considerign you are gonna need plenty of port area.

WOT
07-28-2008, 02:21 PM
Well Ive never tried port forward so I dont know how it would sound.... BUT

My box will be 37.5" wide, and only 31.5 tall. The 4 subs in a perfect tight square need 31" X 31" so I wouldnt have enough room to do port forward if I did subs forward

I wanted to do subs back becuase they would fit perfect on the back wall against the hatch, 2 on the vertical wall, and 2 on the slanted. And then either port forward or port up.

And yes. I need something like 220-250sq/in of port area..... so its gonna be a big port.

djjdnap
07-29-2008, 03:18 AM
i agree wt skateboard

bass-aholic
07-29-2008, 03:29 AM
Well Ive never tried port forward so I dont know how it would sound.... BUT

My box will be 37.5" wide, and only 31.5 tall. The 4 subs in a perfect tight square need 31" X 31" so I wouldnt have enough room to do port forward if I did subs forward

I wanted to do subs back becuase they would fit perfect on the back wall against the hatch, 2 on the vertical wall, and 2 on the slanted. And then either port forward or port up.

And yes. I need something like 220-250sq/in of port area..... so its gonna be a big port.

Actually with those measurements you could do the subs/port forward and it will be a VERY tight fit. I would NEVER do subs back in a wall like that, thats just me though.

WOT
07-29-2008, 03:48 AM
really 4 subs forward eh, and an extremely tight port close to it only 1/2 exposed to the seat?

There isnt alot of room between the box and the rear seat, obviously the top is open, but the box will be 1-2" away where the seat is leaned back the most, maybe 4-5" away at the bottom of the taper of the seat....

Didnt think that was enough clearance

Hmmmm, maybe I can keep my seats folded forwards..... I dont even kno how much the fold Ive never tried to fold them forward before lol

hazardous0388
07-29-2008, 03:50 AM
nice pics

WOT
07-29-2008, 03:53 AM
I love makin pics like that lol, helps me think... cuz its 4am and I gotta work soon lol

WOT
07-29-2008, 03:57 AM
I just bought the second set of 15's from though so hoping they will be here this week. And Im either gonna run them with a pair of cadence txa 1000d's Ive got (dont wanna run them though they make weird noises) or Ive got an eye on a Hifonics Brutus 4000. WIll do 2700+ @ 2ohm giving the woofers a bit more then spec power but Im sure they can take it

Still debating on which design to go with

WOT
07-29-2008, 03:58 AM
And **** if I went port forward sub forward, I might aswell wall the sum***** cheaply with a beauty panel and some stuffing........

WOT
07-29-2008, 05:45 PM
SO you guys are saying I should build it like this, dont mind the crude pic.

http://img397.imageshack.us/img397/6803/73524399cx9.jpg

And I guess I would just mount the amps on the back of the box...

I'll have to see if I can squeeze enough port area in there, I think it would be good though

kicker33
07-29-2008, 05:57 PM
lol i don't know what the pics are but this **** is gonna be loud. o yea the aq's need at least 4-cubes per sub so 16 cubes for 4.....there great subs.

WOT
07-29-2008, 07:14 PM
Ya Ive got the space, its making a good box that I need help with

I dont know if Im gonna be able to squeeze this port though......

if I got 16sqin per cube thats 16X17cubes (might have to make the box a bit smaller) it was something like 270 sq in of port. Im only gonna have like 5.75" of port width with these subs side by side. AND 30.5 of port height after taking away wood thickness

Not enough......

WOT
07-29-2008, 08:35 PM
Alright so I did the math and subs forward and port forward dont work, only have 5.75" port width MAX, and 30.5" height doesnt gimme close to my port area I need

Was thinking of doing subs forward and port up, but since my box is angled on the top it make it kind of tricky......

Was thinking of placing PVC ports on the top near the back of the box or maybe a slot port on the bottom of the back of the box firing into the bottom of the rear hatch.......


Im really stumped here, need ideas

WOT
07-30-2008, 01:23 PM
http://img292.imageshack.us/img292/8189/portupjw0.jpg

Im preobably going with either this

Or subs forward on the face and port across the bottom width of the box.... I dont know if that works though since the subs will be on the opposite side as the subs, dont know if that affects anything, but port depth might be an issue with that one...

Techchild
07-30-2008, 02:03 PM
Why not subs forward and port along the top. all facing forward.

WOT
07-30-2008, 02:22 PM
I dont have the box height to do that, only 32" height, susb stakced need 31"..... cant do it

Techchild
07-30-2008, 05:20 PM
You need to figure out a way to get those facing fowards. What is your max depth from back of seat to trunk door?

kicker33
07-30-2008, 05:22 PM
why don't you do 2 18s?

WOT
07-30-2008, 05:38 PM
Well I can easily do the woofers facing forward, that fits, the port wont fit forward aswell though. Id just be stuck porting to the rear and bottom where i dont have much clearance.

What is wrong with having the subs in an enclosure like I have pictured? Ive tried subs back port up before, sounded the same as port back subs up. With the same box and power.....

just curious whats wrong with that design

And 18's are out of the question. I have the 4 15's now

Rashaddd
07-30-2008, 05:40 PM
http://img127.imageshack.us/img127/6366/designei8.png

No?

Rashaddd
07-30-2008, 05:43 PM
Well I can easily do the woofers facing forward, that fits, the port wont fit forward aswell though. Id just be stuck porting to the rear and bottom where i dont have much clearance.

What is wrong with having the subs in an enclosure like I have pictured? Ive tried subs back port up before, sounded the same as port back subs up. With the same box and power.....

just curious whats wrong with that design

And 18's are out of the question. I have the 4 15's now

The problem is how little room for airflow you have between the back and the front of the box on the outside, but if there's actually plenty of area outside the box then it should be fine, but it'll be better facing forward, plus your hatch is probably going to rattle like a mother

Techchild
07-30-2008, 05:44 PM
What about this I just drew it up real quick. It's pretty much to scale I just don't know the woofer cut out sizes :) Thats with a 40 inch depth thoe.

http://img410.imageshack.us/img410/3500/bigboxju0.jpg

WOT
07-30-2008, 08:38 PM
http://img127.imageshack.us/img127/6366/designei8.png

No?

I couldnt build that, nor do that math. As for techchilds design, that giving up way to much volume at the front being caved in like that, i need every bit of air space possible, and I dont have anywere close to 40" depth.

My first design with the subs back and port up is the best in my head right now. Clearance was mentioned in the last 2 posts, the port itself will have plenty of clearance, its the subs that will be fairly close to my hatch/glass, only a couple inches away.... does that really matter if those have clearance as long as they dont actually hit when playing music?

WOT
07-31-2008, 01:27 PM
00000000000000000000000000000

WOT
08-01-2008, 07:13 PM
Any reason I

SHOULDNT build the box this way, its just the best, cleanest way I can come up with, but I dont no anything about facing the subs back port up. Only had subs forward port up and sub up port back and sealed.....

http://img292.imageshack.us/img292/8189/portupjw0.jpg