Slot port question

[Slawsen]

Ok, I think I got it right this time. The sheets for the type r recommend 15 square inches of port per cu ft..

This will be with the subs on one side and the port on one of the ends

Hope I did good ?

[Slawsen]

Yes. Keep in mind that you measure port length down the middle of the port though.

So how do I figure out how long the port boards need to be? cuz it says 19.15" of physical port length.. so the board that connects to the front baffle would be like 12.25 inches + .75 inch from the front baffle + the L board will be 6.15"??

[R_Mac_1]

I was under the impression that physical port length is measured down the side the way you stated (front port wall length + front baffle thickness + back port length). I thought measuring down the middle + end correction (or whatever it's called) gives you the effective length.

As far as your box, 2.8 cubes seems small for two 12s. Although I'm no expert, from what I've seen most twelves seems to be in the 1.75-2.5 cubes range. I could be wrong here, but it's worth checking out.

Also, don't use 3.1 inches for your port width. Just use 3.

[Slawsen]

I was under the impression that physical port length is measured down the side the way you stated (front port wall length + front baffle thickness + back port length). I thought measuring down the middle + end correction (or whatever it's called) gives you the effective length.

I set the port length to 23 inches, which is if you measured inbetween the port and box, but the calculator goes ahead and calculates the physical length..so I did do it right?

[R_Mac_1]

Check out this thread.

http://www.stevemeadedesigns.com/board/topic/83062-does-this-look-alright-to-you/

The guys port length he entered was 34. Physical port length was 29. His port walls are 14 and 14.25 (14+14.25+.75=29) and torres tells him that it's right.

So, it seems you're right about the physical port length.

[Slawsen]

Check out this thread.

http://www.stevemeadedesigns.com/board/topic/83062-does-this-look-alright-to-you/

The guys port length he entered was 34. Physical port length was 29. His port walls are 14 and 14.25 (14+14.25+.75=29) and torres tells him that it's right.

So, it seems you're right about the physical port length.

Ok sweet...thanks guys. I think i'm gonna go try to assemble it in googlesketchup LOL. I'll post it if I can figure out how to do it

Edit: Gonna be building this box with my friend I think on Friday. Going in his bmw, we gonna do a build log prolly so I can get some feedback and tips

[R_Mac_1]

Like I said I'm no expert, I've just been trying to learn it because I'm about to build a box for my z15. Just used the calculator the other night for mine.

I tried sketchup but was getting irritated so I just drew it out by hand and did the cutsheet by hand.

[MrSkippyJ]

Read this article. It helps explain stuff.

JL's Port tutorial

[pheint_1]

not to thread jack, ive heard about the end correction factor how would one "factor" this length onto the port length?