View Full Version : JBL 123-A1 TS parameters
AlexanderS
03-01-2005, 08:28 AM
Hello, friends,
I am new to this forum.
I am looking for TS parameters of this driver. I guess this is 8 ohm version of JBL 123A. Can anybody help?
Thanks,
Alexander
DONALD G
03-01-2005, 08:42 AM
http://www.jblproservice.com/pdf/Thiele%20Small%20Parameters/Theile%20Parameters.pdf
Welcome !
pdf file. Handy as a pocket on a shirt
Donald,
123A-1 does not appear in this list. Classified military product? :-)
As Alexander told me - this driver has different DC resistance so Q's may be also different or...
4313B
03-01-2005, 09:40 AM
Anyone with a measurement system AND a 123A-1?
Yes, Giskard! You're hundredpercent right.
Anyone - means Alexander won the lot on e-bay,
measurement instruments - he has PC with sound card and I may give him Signal generator and AC milliviltmeter/ impedance measurement tool. He lives 5 km from me, just 20 minutes driving through bloody Moscow traffic.
Anyway it's interesting fact - there is JBL driver which JBL did not list. And it looks totally different from 123A.
AlexanderS
03-02-2005, 06:12 AM
This stands for 8 ohm version:
http://www.bassreflex.de/index/JBL/jbl.htm
Strange is that they wrote 8 ohm, but again 123A (without 1), while the original pdf says 123A has Re=4.4 ohm.
Hi!
Most strange - 123A-1 mentioned here in zillions of threads, as very common thing; but nobody knows the specs.
AlexanderS
03-02-2005, 07:17 AM
This is Xover network with 123-A1
http://www.audioheritage.org/vbulletin/images/attach/pdf.gif
It says Re of 123A-1 is in the range of 4.4 to 5.5 Ohm, while this is 8 ohm impedance driver! Maybe I was wrong?
GordonW
03-02-2005, 06:20 PM
AFAIK, the 123A and 123A-1 are completely interchangable? As in, the same cone mass, same impedence, same Bl product. Should be able to use the specs for the 123A to build a box for a 123A-1, without problem. JBL certainly did, and it worked fine for them!
Regards,
Gordon.
spkrman57
08-28-2005, 08:34 AM
Disclaimer: I am not a professional, take the specs with a grain of salt!
Between a pair of 123A1's, I averaged the pair and came up with these values:
fs - 23hz
Qts - .5
Le - .8mh
Vas - 7.5 ft
Revc - 5.3 ohm
Sensitivity - 87.8db and 91db (WT2 has sensitivity at 1 watt and 2.83v)
I did these in my living room, used "yellow pages" phone book to place driver upright and keep the vent open. This was measured on the ground. I know there are more exacting ways to accomplish this, but I had the drivers handy and wanted a quick peek.
Ron
Lancer
08-28-2005, 08:54 AM
Disclaimer: I am not a professional, take the specs with a grain of salt!
Yeah, well, we need more folks to do these measurements so don't fret about not being a professional.
Please post individual specs though as opposed to any averages.
badman
04-09-2009, 02:38 PM
See attached
ratitifb
04-10-2009, 06:53 AM
attached :blink:
badman
04-10-2009, 10:25 AM
See attached
Dang!
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