2118j port dims.

[kawmic]

I read in specs. the 2118J should be working with a 30cm2 and 8cm long port, in a 14 liter cab. My question is: my 2118 is to be mounted in a 40 liter cab. with a 78cm2 area port, is the port then gonna be shorter than the 14 liter cab. or longer and how much?
Kindly Michael

[Lee in Montreal]

Shorter. Length will depend on the frequency you are tuning to and the compromise you have in mind. Extension vs excursion/power handling.

[Woofer]

There are lots of places on the 'net where you can calculate the port length.
Here's one as an example:
http://www.mobileinformationlabs.com/HowTo-1Woofer-Box-CAL Port lenth 1.htm

[Robh3606]

Try using Win Isd. It's free and you can see what the response will be. I come preloaded with most JBL drivers

http://www.linearteam.dk/default.aspx?pageid=winisd

Rob:)

[Woofer]

Try using Win Isd. It's free and you can see what the response will be. I come preloaded with most JBL drivers

http://www.linearteam.dk/default.aspx?pageid=winisd

Rob:)


... of course, that's if you're a Windows user. ;)
Rob, if you're aware of any Mac programs, I'd be most grateful for any advice.

George.

[Lee in Montreal]

I am on Mac too and use a Excel freeware to plot response and excursion. It works great and is fairly simple to use.

[Robh3606]

Hello George

Here is at least one, never used it being on a PC

Rob:)


http://www.trueaudio.com/mac_aut1.htm

http://www.trueaudio.com/mac_demo.htm

[Woofer]

I am on Mac too and use a Excel freeware to plot response and excursion. It works great and is fairly simple to use.

Does it have a name Lee?
I'll try and search it out.... ;)



Hello George

Here is at least one, never used it being on a PC

Rob:)


http://www.trueaudio.com/mac_aut1.htm

http://www.trueaudio.com/mac_demo.htm

I forgot I had that!
.... albeit a 68k version that I can only run on a Mac running OS 9.0 !!!!!
Lucky my super old iBook can still do that in 'Classic' mode.....
(Mac users will know what I'm talking about, if they're old enough. LoL)

Thanks Rob for reminding me of that. :bouncy:

[kawmic]

thanks for your replies. looks like win-isd is an exellent tool. thanks all again;)

[Lee in Montreal]

Does it have a name Lee?
I'll try and search it out.... ;)

Found it. Designed by Brian Steele. Can be downloaded from www.diysubwoofers.org

I love it. Works on any computer with Excel

http://www.diysubwoofers.org/design/ported.zip

[Woofer]

Found it. Designed by Brian Steele. Can be downloaded from www.diysubwoofers.org (http://www.diysubwoofers.org)

I love it. Works on any computer with Excel

http://www.diysubwoofers.org/design/ported.zip

Thanks heaps for that Lee....