# need help now!!!!!

• 06-07-2004
moses
need help now!!!!!
ok i am building a ported box for 1 15 and the dimensions are 35"L x 20"H x 20"D how wide and long of a port should i have if i wanna tune it to around 32-35 hrtz?
• 06-08-2004
dbornotdb
Re: need help now!!!!!
What 15? What are the T/S parameters? Are those exterior dimensions? Is is 3/4" material?

Or do this..........
http://www.jlaudio.com/tutorials/ports/images/Fb.gif

Fb is the frequency you want the box tuned to........
Av is the cross-sectional area of the port (in square inches)........
Lv is the length of the port (in inches)..........
and Vb is the enlcosure's net volume (in cubic inches). http://www.jlaudio.com/tutorials/ports/index.html/
• 06-08-2004
moses
Re: need help now!!!!!
its for an REaudio SX15 and those are the external dimensions and it is 3/4" i rerally dont understand what u put up so could u use simpler words
• 06-08-2004
Blaith
Re: need help now!!!!!
Quote:

Originally Posted by moses
ok i am building a ported box for 1 15 and the dimensions are 35"L x 20"H x 20"D how wide and long of a port should i have if i wanna tune it to around 32-35 hrtz?

Are you jsut cutting a port into an existing box? or is that the max room you have to work with? if your cutting a port into the box it starts to get complicated... becasue the port volume subtracts from the total volume of the box......

so is this cutting a port into a box, or are you building a box with that being the max dimensions?

Fraz
• 06-08-2004
swimfreak26
Re: need help now!!!!!
assuming .2ft^3 displacement for the sub, you can make a port that is 18.5 x 3 that is 15.71 inches long, and your box will be tuned to approx 33.23Hz
• 06-08-2004
moses
Re: need help now!!!!!
yea im building a new box so i can make any port that u guys recommend but im still not sure if those are the dimensions i will use but i appretiate the help guys
• 06-08-2004
moses
Re: need help now!!!!!
oh yea one more thing will a bigger port mean a lower tuning frequency or will it be a higher frequency?