PDA

View Full Version : box design

rain377
12-12-2007, 10:11 AM
Ok i dont want to mees this one up. just recently built a box for a 15" Fi BL. i completely forgot to take port area into calculation so it doesnt sound like it should. Now i'm getting another BL and am going to build another box. box will be 38" wide, 28" tall 25" deep. port will be coming out of front bottom 36.5" wide 4.5 tall and 43" long. Speakers facing up. I'd put up a pic but dont have one. My question is will port area be ok? and will cubes on the box be too much? With my calculations i'm looking at 164" port area and 9.1ft^3 after displacement. lemme know what you think.

rain377
12-12-2007, 10:14 AM
If its not a good design could someone else send me one? I just want to get full potential out of these subs. They will be seeing about 1800wrms each in a grand cherokee.

dan5505
12-12-2007, 12:42 PM
double check this cus im kinda new to this myself. I was told that for a single 15" the port area should be 50-60 square inches. So im assuming for two drivers it should be double that.

BuckyBoy
12-12-2007, 01:02 PM
double check this cus im kinda new to this myself. I was told that for a single 15" the port area should be 50-60 square inches. So im assuming for two drivers it should be double that.
i thought port area is related to internal volume

dan5505
12-12-2007, 01:08 PM
like i said, i may be wrong. but this calculator doesnt take volume into consideration when calculating port area http://www.carstereo.com/help2/Articles.cfm?id=31
i think the port volume and length is dependent on net volume.

JDBuilder
12-12-2007, 05:55 PM
I have built a few for the BL-15. Now this is based on .5^3ft for sub and bracing and 3/4" product. Try this. 26"H x 38.5"W x 25"D, 12.331^3ft gross vol. Slot port, (down one side), 24.5" x 5" x 26.7"@32Hz. After all displacement, 9.924^3ft net vol. Unless you plan on just SLP comps, this enclosure design will hammer!!

rain377
12-12-2007, 06:11 PM
I have built a few for the BL-15. Now this is based on .5^3ft for sub and bracing and 3/4" product. Try this. 26"H x 38.5"W x 25"D, 12.331^3ft gross vol. Slot port, (down one side), 24.5" x 5" x 26.7"@32Hz. After all displacement, 9.924^3ft net vol. Unless you plan on just SLP comps, this enclosure design will hammer!!

Thank you that was exactly what i was looking for. on this design i want to go port back. should i fire subs up or back?

rain377
12-12-2007, 06:12 PM
also i'm gettingport area at 127sq inches. is that enough?

JDBuilder
12-13-2007, 09:22 AM
You are welcome. I myself like to fire the subs and port in the same direction when at all possible, but you could do subs up port back, it will do fine. As far as the port area, it is plenty for a loud daily driver system. I try to get no less than 45sq inch of port area per 15" sub when I build. Now, if you were to want to do a bunch of comps, then I would say run the tuning up and get more port area, but if you want this loud, but want it to sound good too, this design will do the job for you, and do it very well.
Have Fun & Enjoy,