Can Someone Design For Me?

[usmc7980]

I have a box currently installed and have had a few people express doubts on how it will sound so now I'm looking for a backup design if it does indeed turn out sounding like ass. I've got 3 12" Type R subs, they are Dual 2 Ohm. Each sub will get 500 Rms. I'm mainly looking for a subs up port back design. My dimension are 45" wide max 18" tall and ? on the depth. Im looking for around 30-35 HZ. I'd kinda like something like this. Thanks to anybody that can help

[ALPINE408]

If you go 15 deep with those figures the box will be 7.5 cubes after port and subs it will be around 6 cubes not near my comp so can't tell you port

[usmc7980]

These are all external dims. So 45W x 18H x 15D will work perfectly. If you can help on the port dimension when you get a chance it would be cool Thanks Chris

[quakecitystudio]

I messed with WinISD and came up wih this:

Alpine SWS-3049(couldn't find the type r in the menu)

Box:

vented

board thickness= 0.5 in

w: 45 in

h: 18 in

d: 40 in(Still keeping in mind how you wanted the woofers laid out)

Volume(Vb)= 8.44097 cubic feet

Tuning Freq: 35hz

Port:

1 rectangular port

h=10in w=30in d=6.23 in vent mach:.001

SPL of 1500w at a distance of 1.5m= 129.66 db at 37.61hz

Edited August 12, 2008 by quakecitystudio

[quakecitystudio]

A little sketch from your idea: if any of this helps.

Edited August 13, 2008 by quakecitystudio

[AI James]

you dont think 300 sq in of port is a lil much lol

also why are you using half inch for a wood thickness

Edited August 12, 2008 by James

[quakecitystudio]

Using the formulas on http://www.carstereo.com/help/Articles.cfm?id=31,

and your specifications:

(3) Alpine Type R 12

Xmax= 18.2

Tuning Frequency= 35hz

Usable vent diameter=

Minimum Diameter= 11.55 in

Minimum Area= 104.69in

Length of a Side for a square vent= 10.23

Vent Length(bottom of page):

(1) Square Port

enclosure volume of: 6 cubes

Tuning Freq= 35 hz

Round port of 6 in

VENT LENGTH= 5.98 inches

and a square vent

h=5

AND W=10

VENT LENGTH= 7.5 in

[usmc7980]

Using the formulas on http://www.carstereo.com/help/Articles.cfm?id=31,

and your specifications:

(3) Alpine Type R 12

Xmax= 18.2

Tuning Frequency= 35hz

Usable vent diameter=

Minimum Diameter= 11.55 in

Minimum Area= 104.69in

Length of a Side for a square vent= 10.23

Vent Length(bottom of page):

(1) Square Port

enclosure volume of: 6 cubes

Tuning Freq= 35 hz

Round port of 6 in

VENT LENGTH= 5.98 inches

and a square vent

h=5

AND W=10

VENT LENGTH= 7.5 in

I'm not too good at plugging these numbers in, in real life, so the bold section would be for a square port at the bottom center of the box and it would need to be 5 tall and 10 wide and go into the box 7.5 inches for 50in^2 of port area? I though you should aim for around 15inches^2 per cube of enclosure, would this not create a port noise problem? And there are no dimension on that box a couple posts up so is that the one we're all talking about?

[AI James]

12-16 is normally ok , so his design isnt ok

[usmc7980]

So how would go about getting the right port area and figuring the tuning? I suck at math so bear with me if yall can. Can I just make the opening 12 wide and 7 tall for 84in^2 port area how do I figure the depth?

Edited August 13, 2008 by usmc7980