yo0123yo

07-25-2006, 10:27 AM

can someone tell me the formula to figure out how many cubic feet a box is and the formula to figure out what the port is tuned to? thanks

View Full Version : formula to figure out box tuning and cu ft?

yo0123yo

07-25-2006, 10:27 AM

can someone tell me the formula to figure out how many cubic feet a box is and the formula to figure out what the port is tuned to? thanks

ghart999

07-25-2006, 10:33 AM

can someone tell me the formula to figure out how many cubic feet a box is and the formula to figure out what the port is tuned to? thanks

volume is to measure all 3 dimensions and subtract the thickness of the wood multiplied by 2 (for each side). Then multiple the 3 dimensions together and divide by 1728.

Example: box is 18x14x26 and wood is 3/4" thick. 18 - 1.5 = 16.5 : 14-1.5 = 12.5 : 26 - 1.5 = 24.5

16.5x12.5x24.5 = 5053 div ide that 1728 and you have 2.92 ft^3

I don't know the forumla for tuning.

volume is to measure all 3 dimensions and subtract the thickness of the wood multiplied by 2 (for each side). Then multiple the 3 dimensions together and divide by 1728.

Example: box is 18x14x26 and wood is 3/4" thick. 18 - 1.5 = 16.5 : 14-1.5 = 12.5 : 26 - 1.5 = 24.5

16.5x12.5x24.5 = 5053 div ide that 1728 and you have 2.92 ft^3

I don't know the forumla for tuning.

yo0123yo

07-25-2006, 10:50 AM

cool i just figured out my box is 7.55 cu ft, i got 2 12" L7's, now i just need the tuning formula, oh and if it involves finding port displacement or sub displacement, i dont know how to do that, so can someone explain that as well. thanks :)

Badfastbusa

07-25-2006, 11:25 AM

i believe what ever the sub displacement is you just subtract that for each sub from the calculated volume. im also trying to figure out this whole port thing.

helotaxi

07-25-2006, 11:27 AM

The formula is on JL audio's website under tutorials. Or you can just download one of the myriad free box calc programs and let it crunch the numbers for you.

Badfastbusa

07-25-2006, 11:56 AM

got a link for that box calculator?

helotaxi

07-25-2006, 01:47 PM

http://www.linearteam.dk/default.aspx?download=winisd

acreature

07-25-2006, 01:52 PM

How accurate is this compared to paper and pencil?

http://www.subwoofertools.com/forum/ported-box.asp

http://www.subwoofertools.com/forum/ported-box.asp

helotaxi

07-25-2006, 03:05 PM

All it does is keep you from using a pocket calculator. It uses the same formula and should end up at the same answer.

acreature

07-25-2006, 04:28 PM

All it does is keep you from using a pocket calculator. It uses the same formula and should end up at the same answer.

Are you answering my inquiry above your post?

Are you answering my inquiry above your post?