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View Full Version : trying to get four L5 8" subs tuned to 36 hz



charlesarms85
02-11-2010, 06:05 PM
Hello, I am needing a little help with a box i am building. I am going to be putting four 8" L5 subwoofers in a single cab 08 f150 with the pocket doors. Ive measure the space and its 51w, 22h, and 6d and that should put me around 3.5 cu. f.t before disp. My question is this, I want to do 3-4 round ports beause ive heard they are more acurate. Can someone help me please?

4OZGLOVES
02-11-2010, 06:08 PM
Hello, I am needing a little help with a box i am building. I am going to be putting four 8" L5 subwoofers in a single cab 08 f150 with the pocket doors. Ive measure the space and its 51w, 22h, and 6d and that should put me around 3.5 cu. f.t before disp. My question is this, I want to do 3-4 round ports beause ive heard they are more acurate. Can someone help me please?

if you do 3-4 ports they most likely will be to long to fit in your box. If i was in your situation I would do one 6" aero. I think that would be much easier and It should be enough port area for 3.5 cubes.

charlesarms85
02-11-2010, 06:15 PM
how would i do an aero port? Ive never done round ports before? Or point me in a direction to calculate and be educated on aeroports?

DBBOOM
02-11-2010, 06:25 PM
PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES (http://www.carstereo.com/help/Articles.cfm?id=31)

http://psp-inc.com/tools.html

charlesarms85
02-11-2010, 08:40 PM
Thanks, so 6" round port about 12.5" should be enough to tune the box to 36 hz on 3.5 cu. ft. after disp? I figured roughly .2 cu. ft. per sub disp puts me around 1.0 cu. ft. disp and building the box at 4.3 cu. ft. (52w, 22h, 8.5d) should do the trick

Ronny
02-11-2010, 09:57 PM
*eek* I gurantee each sub does not hold .2cubes of displacement. You should be able to find the exact figures on the webiste or call 'em.

charlesarms85
02-11-2010, 11:25 PM
Ok.... so 49.1 cu. inches PER 8" sub x 4 subs = 196.4 cu. inches converted to cubic feet = 0.113 cubic feet.... am i on the right track here?

Slo_Ride
02-11-2010, 11:27 PM
*eek* I gurantee each sub does not hold .2cubes of displacement. You should be able to find the exact figures on the webiste or call 'em.

x2 i'd guess .1 at the most

charlesarms85
02-12-2010, 02:30 AM
So, all four subs will take up only .113 cu. ft.? So as long as I build the box, lets say, at .8 cu. ft. per sub = 3.2 cu. ft. total, so pretty much build the box to 3.5 cu. ft. and I should be good? Sorry i am being so thorough, just wanna get it right the first time around.

RAM_Designs
02-12-2010, 09:53 AM
You don't have enough room, 51" x 22" x 6" using 3/4" MDF only nets you 2.64ft^3 before displacements...maybe just run sealed or use just a pair of them.

charlesarms85
02-13-2010, 05:46 PM
Just measured again..... 51w, 23h, 7.5

azphat12
02-13-2010, 05:57 PM
Just out of curiosity, with such a tight fit and all. Have you explored the option of a box in the bed of the truck ported to the cab? I had 4 12's in an S10 done this way. Either you lose your cabin room, or you lose your truck bed room.... I believe it was a bandpass box they built for me...was several years ago.

DBBOOM
02-13-2010, 06:15 PM
L7 8"s do better with ~1cu.ft each on a ported build. Build the box to 4.5cu.ft GROSS, after bracing and sub displacement you will be at 3.8-4cu.ft. . Do some simple geometry and find the internal volume. Use the PSP calculator i linked above. If you don't have that much room..........use two or go sealed. Simple enough?

charlesarms85
02-13-2010, 09:03 PM
Your right man, SPL needs 1.0 cu ft, but I don't want ALL spl..... i need it to sound decent on music too.

charlesarms85
02-14-2010, 07:48 PM
Just out of curiosity, with such a tight fit and all. Have you explored the option of a box in the bed of the truck ported to the cab? I had 4 12's in an S10 done this way. Either you lose your cabin room, or you lose your truck bed room.... I believe it was a bandpass box they built for me...was several years ago.

I would, but man, sqeezing a loud set up in a decent size space if fine with me. I have the "pocket doors" on my reg cab so my reg cab is ALOT bigger than most reg cab trucks.

RAM_Designs
02-14-2010, 07:58 PM
Hey Charles, I sent you a PM, let me know if you're interested.

azphat12
02-14-2010, 08:24 PM
Ahh understandable. Was just throwing the idea out there.