6th order bandpass box

[sgthendo]

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.aspYeah 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.

I've already read that article. And a couple others, I've used 4 different port calculators online and they all tell me I need a 4inch diameter by 4inch length port.

Yet every 6th order box over seen the port has been massive

 

[Lbetts818]

Your probably also comparing a 4 18 6th order to a single 12 6th or something. A 30cft box is going to have a massive port.

 

[sgthendo]

Your probably also comparing a 4 18 6th order to a single 12 6th or something. A 30cft box is going to have a massive port.

I'm pushing 2 10s, the total cft of the box is 7.139

 

[sgthendo]

All I'm wondering is, is the Vr of the box the total cubic feet of the front chamber and rear chamber? Or just the cubic feet of the rear chamber?

 

[Jeffdachef 5,000+ posts]

Your probably also comparing a 4 18 6th order to a single 12 6th or something. A 30cft box is going to have a massive port.

40 cubic feet front portion and 20 cubes rear portion lol.

I'm pushing 2 10s, the total cft of the box is 7.139

honestly bro, I'll tell you straight up, this is not something you wanna experiment with unless you plan on doing a lot of rebuilds.

100% sure you'll be happy with a flat ported over a randomly put together 6th order.

Unless you are using sketchup and getting every dimension precise and correct along with having bass box pro to measure projected response and rear air velocity, I would not even bother with a 6th. Most 6ths that people try on their own turn out to be complete and utter flops.

 

[hispls 5,000+ posts]

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

This sounds unlikely. There's a reason almost nobody uses this style box, but if you like woodworking and can afford to build and throw away a few boxes give it a whirl though.

 

[mrj858 10+ year member]

40 cubic feet front portion and 20 cubes rear portion lol.


honestly bro, I'll tell you straight up, this is not something you wanna experiment with unless you plan on doing a lot of rebuilds.

100% sure you'll be happy with a flat ported over a randomly put together 6th order.

Unless you are using sketchup and getting every dimension precise and correct along with having bass box pro to measure projected response and rear air velocity, I would not even bother with a 6th. Most 6ths that people try on their own turn out to be complete and utter flops.

Exactly....when I first metered the 2 18 6th order im running it did a 151.6 sealed on the dash...luckily I made it where I could play with the front and rear ports...went from a 151.6 to a 155 sealed on the dash with out doing anything but playing with the ports...now after swapping subs and adding power it's a monster //content.invisioncic.com/y282845/emoticons/santa.gif.e1ec9cf2e0a0dd232ad35aa594a126d0.gif

 

[Jeffdachef 5,000+ posts]

Exactly....when I first metered the 2 18 6th order im running it did a 151.6 sealed on the dash...luckily I made it where I could play with the front and rear ports...went from a 151.6 to a 155 sealed on the dash with out doing anything but playing with the ports...now after swapping subs and adding power it's a monster //content.invisioncic.com/y282845/emoticons/santa.gif.e1ec9cf2e0a0dd232ad35aa594a126d0.gif

I need to play with mines too, gonna tune the rear chamber lower. But work gets in the way uggh.

 

[Papermaker85 5,000+ posts]

Every woofer is different..I start off around the fs of the driver. Typically use a much larger rear chamber with a front chamber that has a ton of port area.

For example for a parallel design you want the rear chamber to be on the big side of the typical ported box(2.5 for a 12) with the front chamber 1/2 that size and as much port area you can get. Don't worry to much about tuning high on the front focused on getting the desired f3 down low.. you can tuned to 150 if you want it doesn't hurt you have a crossover for that

 

[shredder2]

I've never done a 6th... that bein' said, all this talk about doin' one has gotten me trying to find a way to at least have a starting point... I know that Winisd will not predict too much in this instance, and I chose a driver without seeing if it is compatible first... but am I on the right track?

Any input is greatly appreciated... thank you

 

[Papermaker85 5,000+ posts]

Not what I call a good curve but it depe.ds highly on the cars trasfer function. Start of big and tuned low on both sides

 

[shredder2]

Not what I call a good curve but it depe.ds highly on the cars trasfer function. Start of big and tuned low on both sides

Yeah, I figured the cabin gain would affect the low end a ton... and is a higher than 135hz for the front end desirable?

 

[shredder2]

Here it is with basically a hole in the box... with a .75" vent length... that's 131.64hz... then what next?... test?... I'd like to use a driver that's compatible and does well... anyone know of a good one to use for modeling?

I'm in the dark here... or am I?

 

[shredder2]

Without lowpass filter....

With 80hz lowpass filter...

is this anywhere NEAR close?.. or am I way off base?

 

[Papermaker85 5,000+ posts]

It's looks like you need to shrink the front and tune a tad lower if your doing a 6th order series the rear should be smaller than the front tuned low in arallel I try to keep the ports identical and just shrink the box for a starting point. 2 to 1 for music 3 to 1 for output