Building 1x12 Bass cab

[topcat3355]

I'm not sure if this is the right forum, but I'm looking to build a pair of ported 1x12 cabs out of Eminence beta 12a's . I have WinISD, but am unsure how to get all the specs into a physical box! Haha
Any help would be appreciated

[Balcro]

Hello TC,

First of all, have you got an Eminence Beta 12A or an Eminence 12A-2?

If it's the former, I suggest you send an e-mail to Eminence and ask for the T/S parameters for that specific speaker.
Try [email protected]

The 12A-2 is on the eminence web-site under "Pro-Audio" - American Standard Series. I found two sites with supposed parameters for the older 12A, but when tested, one or more parameters were doubtful, so go to the horses mouth. Then we can help you further. Nominally 250 watts power handling but looking a bit weak in the lower bass.

Balcro

[topcat3355]

Hi Balcro!

I have the older 12a which I've found the t/s parameters for on the eminence site.

http://www.eminence.com/pdf/Beta_12A.pdf

Thanks for your interest

[Balcro]

Hi TC,

My apologies, I should have gone to Specsavers! getting my Alphas & Beta's mixed up. There is
no Beta 12A-2.

Anyway, to get going, start up win ISD. click on the Help menu at the top and select "Getting Started". Have a look at the "Getting Started" chapter. Next, move on to the chapter "Entering new driver data". This suggests a specific order in which to enter data. Remember to go back to this section if you have any notified errors/pop-ups.

Click on "New project". If an error message pops up about "floating point" click OK and carry on.

When the New project - select driver for project dialogue box appears, a name will appear in the centre but I'm sure the Beta 12A isn't on the list, so click the "NEW" button at the side.

On the General Tab enter the name of your loudspeaker. Then click on the paramenters tab. From the Thiele/Small parameters listed in the .pdf file enter the data - Qes, Qms, Vas and Mms.
next is CMS, but be careful of Cms; manufacturers express this in different units. The default in winISD is micrometre/Newtons, but Eminence express their unit in mm/Newtons. For 0.29 enter 290.

At this point, wait while the software does calculations in the background. As you enter the value for Cms, a calculated figure will appear in the "Fs" box at top right. At this point you can test the entered figures are consistent by clicking SAVE. If a file listing box shows up, you're OK - this time cancel. Go back to the parameter entry window and enter BL and Le. Test again. Cancel and return to the parameter window. If all is well at this stage enter the values for Xmax, Pe (rated Power- 250 watts) and Znom (8 ohms). At this point Save for real and give your file a name.

That's entered the driver's details into the winISD database. More tomorrow if you want help with
the new project.

Balcro.