PDA

View Full Version : 123A enclosures



Eric M.
01-19-2015, 08:59 PM
First time post. I'd like to build some ported enclosures for a pair of 123A woofers I have. I was hoping to find the spec sheets JBL put out with their drivers that showed frequency response with specific enclosure and port. I've done some searches here but can only find Theile Perameters for the 123A. Unfortunately, I do not know how to design an enclosure using those perameters. I was wondering if anyone has an enclosure design they are happy with that I could mimic? I read up on the open baffle design but think I'd like to stick with a ported enclosure.

Thanks for any help.

Eric M.

ratitifb
01-20-2015, 12:50 AM
http://www.jblproservice.com/pdf/thiele%20small%20parameters/theile%20parameters.pdf

look at 123A, 2213 (123A-3 like) TS parameters plus some experiments there ;)

http://www.audioheritage.org/vbulletin/showthread.php?4961-JBL-123-A1-TS-parameters

Eric M.
01-20-2015, 01:05 AM
Thanks,

I did run across both of those posts. I just don't know how to use those numbers to build an enclosure.
Maybe a better question might be, where might I look for formulas using TS Perameters to build enclosures?

Eric M.




http://www.jblproservice.com/pdf/thiele%20small%20parameters/theile%20parameters.pdf

look at 123A, 2213 (123A-3 like) TS parameters plus some experiments there ;)

http://www.audioheritage.org/vbulletin/showthread.php?4961-JBL-123-A1-TS-parameters

ratitifb
01-20-2015, 01:20 AM
where might I look for formulas using TS Perameters to build enclosures?


some litterature

http://diyaudioprojects.com/Technical/Papers/Loudspeakers-in-Vented-Boxes-Part-I.pdf
http://diyaudioprojects.com/Technical/Papers/Loudspeakers-in-Vented-Boxes-Part-II.pdf

http://www.hornlautsprecher.net/Dokumente/Grundlagen/Tiele-Smal-LSPRMTRS604.htm

and free WinISD sim software to download and play with

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

Eric M.
01-20-2015, 09:25 AM
Thanks,
Looks like I have some reading to do.

Eric M.

Horn Fanatic
01-20-2015, 04:37 PM
First time post. I'd like to build some ported enclosures for a pair of 123A woofers I have. I was hoping to find the spec sheets JBL put out with their drivers that showed frequency response with specific enclosure and port. I've done some searches here but can only find Theile Perameters for the 123A. Unfortunately, I do not know how to design an enclosure using those perameters. I was wondering if anyone has an enclosure design they are happy with that I could mimic? I read up on the open baffle design but think I'd like to stick with a ported enclosure.

Thanks for any help.

Eric M.

Wasn't the 123A the original woofer used in the L100 Century cabinet?

Eric M.
01-20-2015, 09:33 PM
Yes, I believe you're right. I read on another post that the L100 was not designed very well, the crossover did not even have a low pass filter. I would have used the cabinet and port dimensions of the L100, but I'm under the impression not much effort went into the design.






Wasn't the 123A the original woofer used in the L100 Century cabinet?

ratitifb
01-21-2015, 12:19 AM
the crossover did not even have a low pass filter... , but I'm under the impression not much effort went into the design.the effort went probably into the driver design (cone profil, aquaplas, ...) allowing for the 123a the "wide open" sounding with respect to the LE5-2 low cutoff frequency at -6dB/oct. ...

X-over upgrade :

http://www.troelsgravesen.dk/JBL_L100.htm