JBL 12'' 123A-3 and 123A-1 uses

[vifa32144]

What is the difference between the JBL 123A-1 and 123A-3 twelve inch woofers, and what cabinets were they used in?

[boputnam]

Hey, Gary...

The infamous L100 series, as per the attached.

As you can see, the gap on the 123A-3 is slightly larger at 0.048-in, versus the 0.044 for the 123A-1 (therefore different recone kits).

Most importantly, the 123A-1 is a positive transducer, opposite the JBL "negative" convention as is the property of the 123A-3 (and 2213H, recommended replacement). There's plenty to read on polarity throughout Don's World...

[vifa32144]

If that is the case, from the crossover both would still be connected as the woofers positive and negative terminal posts, right?

[Rex Mills]

I think what Bo is saying, if you can't view the pdf files, is both the 123A-1 and 123A-3 where both L 100 woofers used in 2 different series of that loudspeaker. One woofer is in oppisite polarity to the other. How you hook them up depends on what xover you are using

[boputnam]

Originally posted by vifa32144
If that is the case, from the crossover both would still be connected as the woofers positive and negative terminal posts, right?

I'm confused...

If you've got the:

L100 - connect the 123A-1 Red post to GRN wire (as marked on the schematic). Do not be confused that the GRN wire actually connects to the Black cabinet binding post - that's the way JBL engineered it.

L100A - connect the 123A-1 Red post to GRN wire. In this case, the GRN goes to the Red cabinet binding post.

L100A (Late Model) - connect the 123A-3 Red post to GRN wire. In this case, the GRN goes to the Red cabinet binding post.

[badman]

Couldn't get the chart to paste right, so It's a comparison of a pair of 123A-1 and 2213 (alnico) which should be equivalent to 123A-3. It's entirely possible that the 2213s show the higher Qes (and Qts) and lower Le as a result of lost motor strength from demagging. For my purposes, this is actually desirable, so huzzah!