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View Full Version : My first design/sketchup. Need opinions.



Atimm693
01-13-2008, 06:21 PM
This is the first design ive done by myself, before i used REs calculator or something similar. This time i used WiniSD to calculate the port length and a calculator for the ft^3. This is also the first sketchup ive done. It took me awhile but i think ive figured it out.

The box is supposed to be 2.1 cubes before displacements tuned to 25 htz for HT. Its for one ED EHQS 8. One question i have is how to get the port length i have, i just took the width of the box (11") and doubled plus 8 inches for the slot under it.The port is 1.5 inches wide and supposed to be 30 inches long. If im right ill probably start the build tomorrow or possibly tonight.
Sketchup:

http://i140.photobucket.com/albums/r27/cheechy___chong/SubwooferBox2.jpg
http://i140.photobucket.com/albums/r27/cheechy___chong/SubwooferBox.jpg

EDIT: The box is 11x11x28 internal dimensions, the wood is 1" thick.

BrianChia
01-13-2008, 06:47 PM
You don't want to fold the port like that. You'll get better results if you make it with as few turns as possible (ie. go straight up along the back wall; this gives only (1) 90 deg. turn instead of (4) 90 deg. turns/(2) 180 deg. turns).

As far as measuring the port, the port length should be measured straight down the center of the port as shown below (measured by the black line going down the center). The internal "mouth" of the port is usually measured along a 45 deg. angle to the cutoff of the slot opening, as an "end correction" since the effective length of the port extends slightly past the wall. This is really just an estimate and often makes a negligible difference since many other factors can affect the effective length of the port such as width/length ratio, turns, etc. Tuning will never be exact as calculated by forumla but but will vary slightly due to many other factors. As long as you're close there should be no audible difference.

http://img519.imageshack.us/img519/6389/portlengthyd0.png

Atimm693
01-13-2008, 08:38 PM
Heres another one i made, with the port like you said.

http://i140.photobucket.com/albums/r27/cheechy___chong/SWbox.jpg

Any better?

BrianChia
01-13-2008, 08:40 PM
Yes, I like that design better. What are you powering it with?

Atimm693
01-13-2008, 08:46 PM
For now an RCA HTIB that IIRC does 100 RMS off the sub channel.

mobeious
01-13-2008, 09:02 PM
if i were u i would make the box longer so the port didnt have to L and shoot it strait out the side of the port and move ur sub to the other end of the box

Atimm693
01-13-2008, 09:35 PM
if i were u i would make the box longer so the port didnt have to L and shoot it strait out the side of the port and move ur sub to the other end of the box

The wood i have laying around isnt the right size for that.

Does anyone know how to show the dimensions on sketchup?

BuckyBoy
01-13-2008, 09:49 PM
There is a tape measure on the toolbar. Click it and then click the line you want to know the dimensions of and drag it.

Atimm693
01-13-2008, 09:57 PM
There is a tape measure on the toolbar. Click it and then click the line you want to know the dimensions of and drag it.

I know that but how do i get it to display them on all the panels.

BrianChia
01-13-2008, 10:09 PM
The Dimensions button isn't on the standard toolset. You need to go to View -> Toolbars -> "Large Tool Set". Then click on the dimensions button which is right next to the tape measure. Then you can get a dimension on any two points in the model.