Slot port box help.

[HondaSI 10+ year member]

Hello I'm trying to help a buddy build a ported box for 1 American Bass XD 12 dual 2ohm he's gonna be running it at 1 ohm by a diamond d6 2000.1 amp . I put the specs in a box program he wants the box wide so here are the specs I entered

18L x 32W x 13.5H and 12inch port 2in wide 36hz 24 inches of port area, would this work and have no port noise? Oh and sub and port facing trunk..

Click to read more...

 

[HondaSI 10+ year member]

Bump

 

[HondaSI 10+ year member]

Anybody?

 

[turtlestrap]

Just as a rough estimate the max port velocity is 103 ft/s ~31m/s

That's with a 24in^2 cross sectional slot port area, 11.25 inches long with 0.732 end correction.

 

[HondaSI 10+ year member]

Showing 37hz wanna be at 35 or close ... is what ur seeing good? and is that good with my specs tho?? Or am I doing something wrong

 

[turtlestrap]

i just put in 3.0 ft^3 for volume and a rectangular port with 24 in^2 area and 11.25 in long with .732 end correction. No idea what end correction is, but it auto-filled it in, so I left it. And all that gives 37.46 Hz tuning frequency.

And with 500W at 1 ohm with all the t/s parameters I found online for the AB XD 1222AB, you will have max port velocity at ~103ft/s which is equal to ~31 m/s.

Either way, I think your port is too small. Depending on the source, people try to keep max velocity anywhere from 15m/s - 25m/s. That being said, I have no idea how fast air has to be moving for you to hear it. Increasing port area will make port longer and force you to make your box bigger to keep volume where you want it.

 

[HondaSI 10+ year member]

So what would the cut sheet look like?

 

[turtlestrap]

What do you mean? I literally just used the information from your screenshot above? So it would be the same cutsheet in your screenshot. I didn't change anything. I just modeled what you gave me.

 

[HondaSI 10+ year member]

I just need to make the port bigger right?

 

[Jeffdachef 5,000+ posts]

I just need to make the port bigger right?

yes where it says port per foot, keep it around 12 to 14 for those subs

 

[HondaSI 10+ year member]

Ok let me see what I can come up with

 

[HondaSI 10+ year member]

@Jeffdachef how's this??

 

[Jeffdachef 5,000+ posts]

[quote name='HondaSI']@Jeffdachef how's this??[/QUOTE]

If you wanna stay on your phone, i'd recommend using xplicit audio's box calculator app instead, because your current calculator cannot factor in common port walls, its treating the L slot like a square/rectangle port instead which is inaccurate, its indicated by the port top and port bottom part in your cutout sheet.

If you are on the computer, use torres box calculator.

 

[HondaSI 10+ year member]

Ok I'll do so then get back too u

 

[Jeffdachef 5,000+ posts]

Ok I'll do so then get back too u

Download link along with quick tutorial about common port walls.

Torres' Box Tuning Calculator - Updated 8/18 - Subwoofers / Enclosures - SMD Forum