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imai
01-24-2022, 08:24 AM
HI a long time ago I changed 2213H which had deteriorated suspension with a 123A-1 believing they were interchangeable.
Now I have discovered that 2213h is a negative transducer and 123a-1 is a positive transducer.
What should I do now since the crossover is original... reverse the cables that come from the cross over behind the 123a-1?
or you have to change the cross over ??
someone can help me technically

thanks luigi

Doctor_Electron
06-04-2022, 06:54 AM
Belated Greetings,
All you would need to do is reverse the pair of wires going to the woofer, since the woofers are the only component that have been changed. I suggest that you listen to the monitors one at a time, with the woofers wired in each configuration. Listen one monitor, then reverse the woofer wires and listen to it again.

When the woofer is not phased correctly in relationship to the mid and high drivers, you should notice a significant degradation in sound quality. It will be quite obvious, especially when listening to the vocal range of frequencies.
Some years ago I ran into a similar situation after rewiring my 4410 monitors and not labeling everything properly. With the midrange drivers connected the wrong way, the previously excellent sounding 4410's were absolutely unlistenable.
When doing the listening tests, be sure to listen from several different locations in the room, to avoid choosing the wrong configuration because the characteristics of the room might happen to interact with the speakers and create a somewhat "sweet spot" at one listening position, and if it did, that position would likely be the one and only position where an improperly phased 4312 could sound more or less listenable.
I hope this helps you. I wish that I had noticed your post earlier. By the way, what style of music is your main choice?
Regards, D.E.

JBLS I’ve owned: L65 Jubals, 4310 Control Monitors, 4311 Control Monitors, 4410 studio monitors, 4412 studio monitors, pair of JBL Ampex spec LE-8T 8” full range in portable Ampex “suitcase amps”, L100 Centuries, pair of homebuilt systems with 2235’s in 5 cu. ft. bass cabinets and upper cabs with 2380 biradial horns on 2440 mids, and 2405 high freq. Tweeters. Crossovers were JBL 5233 active for bass to mid crossing, and JBL modified 3107 Networks for the 2440 to 2405 crossing. Too many JBL musical instrument loudspeakers to remember.