Box Design - Retry...

[pervertatoid 10+ year member]

Okay, I see where I screwed up the last box design...this one is supposed to be:

- Just over 3 cubic feet after displacement (0.276 cu. ft. of subwoofer displacement)

- Tuned to 29Hz

Is this right?

Thanks in advance for all the help!

Click to read more...

 

[pervertatoid 10+ year member]

So here I am calculating for a single vent and then dividing the vent length in half to make two...I'm obviously a n00b.

I'll post this again once more...

 

[pervertatoid 10+ year member]

Okay. Here's the "finished" product. Hopefully NOW I have everything right.

Assume both ports are equal in size.

 

[mikey060 10+ year member]

So here I am calculating for a single vent and then dividing the vent length in half to make two...I'm obviously a n00b.
I'll post this again once more...

arent you suppose to divide the enclosure volume by 2? then the resulting port length is for each port

 

[IonSQL 10+ year member]

The box you're showing on the bottom is 3.375cf (after sub displacement) tuned to ~38Hz

But, it's not going to work very well. First, the port area is too little, needs to be 40 sq in at a MINIMUM (you've got 24 sq in).... and the port needs to stay at a 1:8 ratio or less (yours is 1:12). Make the port 2" wide and you'll be better off, of course that makes them longer as well.

 

[pervertatoid 10+ year member]

Okay, I'm officially lost. What am I doing wrong? I used WinISD to calculate my port size, and it told me that the dimensions I put would give me a 29Hz tuning for those two ports. It also said the "Vent Mach" (and I don't even know what that is) was 0.11, which was green instead of red (and I assumed green was good and red was bad, but hey, I could be wrong). I followed ngsm13's tutorial for designing a ported box (here). Apparently I'm screwing something up, though. 38Hz, and not 29Hz, the port volume isn't big enough...I don't know what to say, I'm at a total loss.

 

[IonSQL 10+ year member]

Are you sure you entered a "2" for the number of ports?

If I do it with a single port, 1"x12", it shows 28-29Hz...

 

[pervertatoid 10+ year member]

I don't even know what I did anymore. I can't get it to tell me anything that's the same. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[pervertatoid 10+ year member]

Oh, right. I forgot to tell it not to be tuned at 35Hz. So it's not supposed to be 29Hz.

 

[djman37 5,000+ posts]

i've had more luck making two boxes in 1 enclosure. put a board down the middle and you have two separate boxes.

I designed for 1 sub, then mirrored it to get both subs in 1 enclosure.

Ports in the middle... O || O with a single baffle to split the box, subs on the outside.

 

[pervertatoid 10+ year member]

Even still, what's this rule about 1:8?

 

[pervertatoid 10+ year member]

I'm trying to do three subs in this enclosure, though...

 

[IonSQL 10+ year member]

Even still, what's this rule about 1:8?

If the port width is 1", then the max height should be 8"

If the port width is 2", then the max height should be 16"

If the port width is 3", then the max height should be 24"

and so on, and so on...