Project Build for dan69372. Dual 12 enclosure 4.3 cubic feet @ 32 HZ Pics

[JimBo930 10+ year member]

Binding posts FTW

 

[iamamp3pimp 5,000+ posts]

You can only have 10 images per post.

 

[xluben 10+ year member]

hmm, my calculations give about 3.7 ft^3 net, tuned to around 35Hz. i think you forgot to include port displacement when calculating tuning...

 

[iamamp3pimp 5,000+ posts]

hmm, my calculations give about 3.7 ft^3 net, tuned to around 35Hz. i think you forgot to include port displacement when calculating tuning...

Like to see your calculator......

 

[Flipx99 5,000+ posts]

How do you compensate for have the port in the middle as opposed to the sides? Say port length is 15" and you want a center port, does each side of the port need to be 15?

 

[iamamp3pimp 5,000+ posts]

yes both sides need to be equal.

 

[xluben 10+ year member]

=[(32-1.5)*(14.5-1.5)*(22.25-1.5)]/1728

=4.76 ft^3 internal volume not factoring in port displacement

=(13*4*25)/1728

=0.75 ft^3 port volume

=[(13*0.75*25)/1728]*2

=0.28 ft^3 displacement of MDF used to make the port

=4.76-0.72-0.27-0.16 (0.16 is driver disp. estimate)

=3.57 ft^3 net volume after all displacements

Plug that into WinISD and it says 36Hz tuning.

The only reason I noticed is the dimensions are nearly the same as this box:

http://img10.imageshack.us/img10/4435/35cubes32hz50sqin6lw.png

which I was going to build, and I noticed that the port wasn't quite as long, so the tuning must be higher.

But I really like the box, looks great. It would be a perfect fit in my trunk, and if the port walls were extended a couple inches the tuning would be what I am looking for also //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[iamamp3pimp 5,000+ posts]

winisd doesnt factor in port displacement for tuning, therefore, the volume that you add into the *Volume* field, is gross, not net. once you factor out the sub/port wall displacement, thats how you get your correct tuning.

 

[dan69372 10+ year member]

thanks for everything man

 

[iamamp3pimp 5,000+ posts]

No problem bro. be careful when you get it....its a heavy bish

 

[DBfan187 5,000+ posts]

=[(32-1.5)*(14.5-1.5)*(22.25-1.5)]/1728=4.76 ft^3 internal volume not factoring in port displacement

=(13*4*25)/1728

=0.75 ft^3 port volume

=[(13*0.75*25)/1728]*2

=0.28 ft^3 displacement of MDF used to make the port

=4.76-0.72-0.27-0.16 (0.16 is driver disp. estimate)

=3.57 ft^3 net volume after all displacements

Plug that into WinISD and it says 36Hz tuning.

The only reason I noticed is the dimensions are nearly the same as this box:

http://img10.imageshack.us/img10/4435/35cubes32hz50sqin6lw.png

which I was going to build, and I noticed that the port wasn't quite as long, so the tuning must be higher.

But I really like the box, looks great. It would be a perfect fit in my trunk, and if the port walls were extended a couple inches the tuning would be what I am looking for also //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Port Displacement
if it uses of the sides of the box for one side of its port wall, then:

(port height) x (port length-wood thickness) x (port width + wood thickness) / 1728

if the ports in the middle of the box, and has its own walls, then:

(port height) x (port length - wood thickness) x [port width + 2(wood thickness)] / 1728

 

[PV Audio 5,000+ posts]

Mike, do you like seafood? Extremely large shrimp to be exact?

 

[xluben 10+ year member]

winisd doesnt factor in port displacement for tuning, therefore, the volume that you add into the *Volume* field, is gross, not net. once you factor out the sub/port wall displacement, thats how you get your correct tuning.

I don't know if I completely understand what you said, but I'm pretty sure you need to enter the net volume in WinISD.

Port Displacement
if it uses of the sides of the box for one side of its port wall, then:

(port height) x (port length-wood thickness) x (port width + wood thickness) / 1728

if the ports in the middle of the box, and has its own walls, then:

(port height) x (port length - wood thickness) x [port width + 2(wood thickness)] / 1728

Yep, my mistake. I think that is why I got slightly different results than when I posetd earlier (because I had done it correctly then).

 

[Mike yayo 10+ year member]

Thats a nice looking box.

 

[DBfan187 5,000+ posts]

Mike, do you like seafood? Extremely large shrimp to be exact?

I love PRAWNS!