box specs for 2 2008 18" BL's help

[BLslabFleetwood 0]

ok, i done a trunk build but ports not tuned right and i want to get lower and louder so im going to be removing the rear seat in my 95 fleetwood and thats where the box shall go. i want to keep it at window line so these are my max measurements to work with

height 23"

depth 26"

width 56"

height really needs to be 22"-23" but the width and depth can be smaller if need be, with those specs its around 16.5 cubes before subs and port, i want to be tuned around 32-33hz for rap music

whats the best size box for this application, please help, any help is mucho appreciated

[BLslabFleetwood 0]

before anyone ask, running sundown 1500's on each one wired at .5 ohms the electrical is good also

i know Fi recommends 5-10 cubes per sub and i have a total of 16 cubes to work with i just looking for someone who maybe test and tuned and found out that 14 cubes is better than 10 cubes, ect.

[dbsupra 69]

Download WinIsd free program. The beta version does less but is easier to use than the alpha version.

You can model different size enclosures and it will show you the response difference between them. It won't be perfect due to cabin gain but will give you a good idea.

Typically a larger box will be more efficient and have a little more gain on low end extension.

Don't forget the port area of 12-16 sq in per cu ft. Having too small of a port will seriously effect output.

[BLslabFleetwood 0]

yea i know about the port thing, tuning was off and playing way to low in the trunk box, live and learn, anyway i was messing around in torres and have box specs, now im just having an issue how to build the port.

box is 23" deep but the port is 26" and in the center of the subs so id figure i have to make it open at the on both sides like a "T" but having problems on how to get it right

heres the specs

[BLslabFleetwood 0]

not sure if this will work but maybe you can give input...drawing is crude and not to specs but you get the idea...see if my math seems right and will work

if the box is 23" deep and i need a port 7" wide by 26" long.

lets say i go 7" wide and 16" long, that will keep me 7" of the back wall, then i still need an equaled out 7" so i do a 90 on the left and right at 3.5" each

looks good or what, i wanna get to building now

[dbsupra 69]

If the box is 23" deep you can't go 16" deep and maintain 7" off the back wall. You would have to subtract .75 or 1.5 depending on how thick your wall is. You only have to subtract one wall thickness since the port uses one wall.

From there you can calculate the legs on either side. Take the physical port length calculation and subtract from the straight section.

This doesn't allow for end correction I don't believe. I'm out in the shop working on mine now. Maybe this will give you what you need or someone else can chime in. I don't really build t ports.

[BLslabFleetwood 0]

got ya, forgot thats outside deminsions...

[BLslabFleetwood 0]

im using 3/4 so it would be 15.25" deep and then it would be 1.8" onthe left and right 90...i think

[BLslabFleetwood 0]

1 last question b/c im not use to using torres box calculator. when do the port it measures port legnth from the front baffle correct...mean i start from the outside surface with my 26", not from the rear baffle

another crude drawing, but the left is correct right