tuning, whats your tuned to?

[xluben 10+ year member]

i believe that has been discussed before and winisd uses NET volume (after sub/port displacement)

 

[kotec123 10+ year member]

5 hz

 

[jeepintn 10+ year member]

if i lock the internal volume after port using bbp, it gives me the same lengths, thats why i theorize that winISD uses before port volumes

 

[2loud4u 10+ year member]

35hz and will finaly get to test it out wednesday

 

[jeepintn 10+ year member]

thanks for the replys guys, i really want to tune mine to 35hz, i just cant figure out why bassboxpro is making it so long, like 139 inches long port to do that... port experts please help... before port my enclosure is 6.375 cubes, and my port area is 12.5 x 8.. how long to tune to 35hz?

 

[Captain_Ahab 5,000+ posts]

35hz here.. Gets loud and has some low end.. I love it!

 

[LeofromtheH 10+ year member]

15 L7 @ 30 hz:yumyum:

 

[xluben 10+ year member]

Done by hand:

This formula is also from "The Loudspeaker Design Cookbook". It tells you how long you need to make the vent.Fb - is the tuning frequency of your enclosure in Hertz.

Lv - is the length of your port in inches.

R - is the inside radius of your vent tube.

Vb - is the internal volume of your enclosure in cubic inches. To convert cubic feet to cubic inches, multiply by 1728.

If you want to calculate square vents, the formula below will give you the value of R to use in the formula above.

In the formula above, a is the area of your square vent (height x width), and Pi (Pi) is approximately 3.141592.

For your box (approximated port using a round port of equal area):

12.5 * 7.25 = 90.625

sqrt( 90.625 / 3.14 ) = 5.37

Lv = ( 1.463 * 10^7 * 5.37^2 ) / ( 35^2 * 6.375 * 1728) - 1.463 * 5.37

Lv = 23.4"

Make the acutal port about 2 feet long and you're good!

Hope that helps!

 

[jeepintn 10+ year member]

Done by hand:


For your box (approximated port using a round port of equal area):

12.5 * 7.25 = 90.625

sqrt( 90.625 / 3.14 ) = 5.37

Lv = ( 1.463 * 10^7 * 5.37^2 ) / ( 35^2 * 6.375 * 1728) - 1.463 * 5.37

Lv = 23.4"

Make the acutal port about 2 feet long and you're good!

Hope that helps!

i totally get that man, and i cant understate how much i appreciate it.. but i thought, and im a noob at these things, that once you get your length, dont u subtract that from the volume then recalculate? it just seems like calculating it using 6.375 and it giving u a length, isnt factoring in the loss of volume after adding the port...

 

[Worlddre 5,000+ posts]

depending on the box im using that day

double chamber ported is tuned to 31 and 26hz

and single chamber ported is tuned to 27hz

 

[jeepintn 10+ year member]

ttt for confusing different port help... everything gives different lengths

 

[baseballer1100 5,000+ posts]

33 hz

 

[orphe 10+ year member]

I think Im tuned around 37 -39 hz

 

[Worlddre 5,000+ posts]

i totally get that man, and i cant understate how much i appreciate it.. but i thought, and im a noob at these things, that once you get your length, dont u subtract that from the volume then recalculate? it just seems like calculating it using 6.375 and it giving u a length, isnt factoring in the loss of volume after adding the port...

when designing a box you add the port to the actual box volume to to come up with the gross internal volume which should be that of the box and port together