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Triumph Don
09-21-2003, 05:55 PM
Can anyone describe the sonic difference between the 122, 123, and 128 series 12" woofers? Still working on my low DB bedroom system. McIntosh 754 amp, 113 preamp tuner. Thanks!

Robh3606
09-21-2003, 07:10 PM
Hello

Well the 123 is alnico with a curvilinear cone a couple of versions D123 fullrange with an aluminum dust cap and the famous white woofer in the L100 123. The 122 has a larger magnet also alnico was used in the L166 Horizon and the A version of the L65 Jubal, Two versions one with and a mass ring one without. The 128 is a Ferrite woofer used in the L112 Century 2 and in various versions in the 4412 and TI series 120Ti.

Sonic well the 123a will tune with a hump in the 40-70hz range in a 2-3 ft cabinet but was used wide open in the 4311/L100 so its rool of is smooth. The 122 will tune up flat and has a more extended lowend than the 123. Sounds fine to me. The 128H-1 that I have is very smooth and just a nice sounding driver. Lower distortion by virtue of its SFG motor.

Rob :)

speakerdave
09-22-2003, 12:06 AM
I can confirm the remarks about the D123, 123A and the 122A. I'm not familiar with the 128. The D123 has a nice sound but should have about a 3.5 ft cabinet and should be crossed over at 3500 or below. You can match it with the LE20 tweeter using the LX2 crossover. Good pairs go on eBay for between $150 and $200. I have two pairs that are available, one considerably cheaper than that, if you want to send me a PM.

The 123A was made in two versions, 123A-1 and the 124A-3. The only difference between them that I am aware of is the frames. These will make a punchy sound in a small enclosure. The D123, I believe, is no longer supported by JBL. The 123A can be reconed, but very expensive. None of these have foam surrounds.

The 122A has a foam surround and most on the market will be candidates or will already have been done--competently or not. This woofer is similar in some ways to the 124A--the same free air resonance of 17 Hz--but it has a smaller motor and a three inch voice coil not the four inch. I have this woofer in my L65As and now that the new foam has relaxed it's a decent woofer in a 2ft box. The 122A price on eBay is unpredictable, but I've seen them go for over $200 a pair.

The 124A/2203 is a rare and wonderful beast, and I think the 2203H, the ferrite version, is almost as hard to come by. Both have foam surrounds and I believe the cone kit is no longer available.

I don't know what your budget is, but the 12 inch woofer used in the LSR 32, the 252G, is available new for about $235 each. It's a "modern combination" dual voice coil with an additional brake coil, rubber surround--no foam-- and neodymium magnet and is far superior to the above mentioned woofers.

Have fun,

David

Guido
09-22-2003, 04:35 AM
Originally posted by speakerdave
I don't know what your budget is, but the 12 inch woofer used in the LSR 32, the 252G, is available new for about $235 each. It's a "modern combination" dual voice coil with an additional brake coil, rubber surround--no foam-- and neodymium magnet and is far superior to the above mentioned woofers.
David

I always wanted to ask this:confused:

How can one handle these double voice coil in a stereo system? How do the T/S values differ if only one coil is in use?

What is a break coil?

Thanks!

4313B
09-22-2003, 06:47 AM
http://www.jblpro.com/pub/technote/tn_v3n02.pdf

Triumph Don
09-22-2003, 11:22 PM
Thanks for your input! I just added a pair of refoamed 122 A's to my inventory. Remember, this is for a low DB system in a small room. How will these sound replacing the 123's in an L100 cabinet with original crossovers? Should I just try to find a non existant pair of Jubals?

4313B
09-24-2003, 09:54 AM
Originally posted by speakerdave
The 124A/2203 is a rare and wonderful beast, and I think the 2203H, the ferrite version, is almost as hard to come by. Both have foam surrounds and I believe the cone kit is no longer available.

Well, this is true. It seems JBL has given up on yet another transducer. The 124A/124H/2203A/2203H kit is NLA "forever". However, all is not lost. There is presently a workaround so if you need any of theses drivers serviced send me a PM :)