6th order bandpass box

[sgthendo]

I think this port calculator I'm using is way off, it's telling me that with a box that's 1.32407ft^3, tuned to 25Hz, with a 2"Diameter port. The port length will be 9" long.

 

[Boomin_tahoe 5,000+ posts]

I think this port calculator I'm using is way off, it's telling me that with a box that's 1.32407ft^3, tuned to 25Hz, with a 2"Diameter port. The port length will be 9" long.

ya think?! I would close it now and never look back //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[sgthendo]

It's showing the same result on the12volt.com, carstereo.com, and mobileinformationlabs.com

I'll try to upload the draft of my design.

 

[YukonXL04]

What sub is going in this box? Because the 2" port is likely way too small

 

[sgthendo]

What sub is going in this box? Because the 2" port is likely way too small

a sundown X10d2

 

[sgthendo]

 

[Jeffdachef 5,000+ posts]

It's showing the same result on the12volt.com, carstereo.com, and mobileinformationlabs.com
I'll try to upload the draft of my design.

you never use any of those sites to design boxes dude. They dont account for the space the port takes up nor do they tell you anything about rear air velocity. Just because you reached desired tuning frequency doesnt mean its right. Port area plays a huge *** fking role in terms of overall system performance, cant just slap whatever sized port in and think you'll be good.

 

[sgthendo]

you never use any of those sites to design boxes dude. They dont account for the space the port takes up nor do they tell you anything about rear air velocity. Just because you reached desired tuning frequency doesnt mean its right. Port area plays a huge *** fking role in terms of overall system performance, cant just slap whatever sized port in and think you'll be good.

I know, ive been trying to find the actual math equation to find the proper tuning of a box, but I haven't had any luck at all.

 

[THATpurpleKUSH 5,000+ posts]

A 2 inch port is way too small, use a 3 for the higher tune and a 4 for the lower tune or 4s for both.

 

[sgthendo]

A 2 inch port is way too small, use a 3 for the higher tune and a 4 for the lower tune or 4s for both.

so a total of 4 4" ports?

 

[THATpurpleKUSH 5,000+ posts]

so a total of 4 4" ports?

No 2 4's or a 3 and a 4.

If it's a higher excursion sub and you can fit the longer length, you might be able to do a 4 in the high tuned chamber and a 6 for the lower tuned side.

 

[kr15 5,000+ posts]

No^^

The rear, lower tuned chamber needs less port area than the front, higher tuned chamber.

 

[sgthendo]

So a 3"Dx8"L port per sub chamber(2 chambers)

And two 4"Dx6"L ports for the large high freq chamber?

 

[sgthendo]

Alright, so I figured out what I was doing wrong. I had the Vf and Vr mixed up...

The Vf is tuned to 30Hz at 1.137ft^3 with two 3"Dx7"L ports.

But I'm having an issue figuring out the Vr port size //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif it is 4.871ft^3... I don't know what size to make the port.

Or is the Vr' s cubic feet the overall cubic feet of the whole box???

 

[Lbetts818]

Could be wrong but pretty sure google is still free. If this is that difficult to figure out after two days still and unlimited internet I would just stop. It's not going to sound good unless you pay a pro to do the design. But anyways found this in 5 min for you. Best of luck. https://www.the12volt.com/caraudio/boxes6.asp

Yeah it's not the best source for info. But op a 6th may not be your best bet. It's not some unicorn that's going to get you in the 160s with cheap gear.