What's this tuned to?

[jiggy2dmax]

I got a veryyyy nice box from a customer today but I have no idea what its ported to. The dimensions are

Width- 18"
Lenth- 12"
Height- 12"

The port opening is about 1 1/4 inch and each part of the port is 1 1/4 inches apart and are two pieces, 10 3/4 each.

[bcarpenterfhl]

The port opening is about 1 1/4 inch and each part of the port is 1 1/4 inches apart and are two pieces, 10 3/4 each.

what?!?!? are you saying the port width is consistently 1 1/4 in., and the length is 10 3/4 in.? how tall is the port? does it make an "L" shape?

[sumone]

is this an L-shaped port...hard to understand from your wording...

you don't say how the port is oriented...


if it is an l-shaped one...

1. figure out the port length = Lv

2. figure out & subtract the port displacement from the gross interior volume = Vb

3. figure out the port area (1.25 * whatever) = Av

Solve for Fb in

(Av*1.84*10^8)/(Vb*1728*(Fb/.159)^2) - 0.823*Sqrt[Av]

or

TunFreq[Av_, Vb_, PLen_] := Sqrt[1/(((PLen + 0.823*Sqrt[Av] )/(Av*1.84*10^8))*(Vb * 1728)) * .159^2]

[jiggy2dmax]

ok sorry for the crappy a$$ explanation. The port lenth is 1 1/4 throught out. Its not a "L" port. It has two pieces of wood adjacent to each other forming the port and each is 10 3/4. The port is also 12inches high. Thanx guys.

[negativezeroz]

you know how about you draw everyone a nice pic in paint

[jiggy2dmax]

well heres a pic:

[pwnt by pat]

That's freaking tiny, even at 640x480. To keep the size down, save as a JPG.

[jiggy2dmax]

Sorry the pic didn;t come out very well. Basically the port is 1/ 14 inches wide, 12 inches long and not a L shape. It has two port boards that are 10 3/4 inches long.

[supa_c]

Laberynth(sp?) port

[mrray13]

if ur measurements are external and the box is 3/4mdf.....the tuning is close to 45hz


if the measurements are internal....the tuning is about 36hz


the port is about 24 5/8" long..



if i got the port length correct, those numbers were provided by bb6p






wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

[Str8Up]

Hey,

What about a box with external dimensions 26"W x 17"H x 16"D using 3/4" wood.
And the vent is 31" x 15.5" x 2"....What is the box tuned too? Btw, take away .2 cubic feet because that's how much my sub displaces.

I'm hoping it'll be tuned around 31-33hz for my 15AE. I just don't know who I'll get to build it yet

[mrray13]

tuned about in between 34-35hz, according to bb6p





wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eee

[Str8Up]

tuned about in between 34-35hz, according to bb6p





wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eee

Thanx man. It's weird how different calculators tell different things. My calculator I use says between 32 and 33hz. O well, in-car it probably won't be 3db down until around 28hz or something anyway, which is fine.

Thanx again.

[mrray13]

Thanx man. It's weird how different calculators tell different things. My calculator I use says between 32 and 33hz. O well, in-car it probably won't be 3db down until around 28hz or something anyway, which is fine.

Thanx again.

no problem..and ur pretty close either way.





i build boxes..pm me...









wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

[jiggy2dmax]

dam 45hz, dats suxx. Anyway I can lower it, I would think by expanding the port lenth? If I can how much more port do I need to get it to about 33- 34 hz?