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Triumph Don
09-23-2003, 12:13 AM
I just got a pair of mint 122 A's, how would they sound different than the 123's in L 100 cabinets with stock crossovers? Again, looking for a resonable [price] low DB system w/ the old Mc amps. I have a pair of beat up L 65's also. Space is at a premium.

boputnam
09-23-2003, 02:02 PM
My wifey loves this thread title... ;)

Anyway, I don't know the 122A as well as I do the 123A, but do know the 123A is a positive transducer, so you'll need to watch the polarity of whatever you swap in here, and maintain that intended by the original L100 design.

However, unless you have the 122A's, I have elsewhere suggested the 128H be given a try (on advice of Giskard...) - it is IMHO the best 12-in LF JBL produced and will markedly improve the low-end of the L100.

Robh3606
09-23-2003, 03:22 PM
If you look at the 122A and 128H they model very well/flat and very similar. The 122A goes a bit deeper for the same box size. However the 128H sounds smoother up top, at least to me. I want to get my 129H working and run them in my XPL's. With the 122A as Bo says you have to reverse the leads to the woofer. Give them a try only problem is I for one don't know how smooth they roll off. Both the L166 and L65 rolled them off.

Rob:)

GordonW
09-23-2003, 08:38 PM
I wouldn't use the 122A in the L100, stock otherwise... with the 122A's larger magnet increasing bandwidth and straight-sided cone (vs the curvilinear cone in the 123A) causing beaming on-axis compared to the 123A, you won't have the natural high-end roll-off that the 123A had in the L100, with no crossover on the woofer there.

If you did this, you might want to try using the L65 crossover with the L100 cabinet... that should get the response of the drivers in line. Or better yet, put the good 122As in the L65s you have- you could even rob the LE5s from the L100 for the L65 as well, if necessary- those are, ostensibly, the right drivers (122A, LE5) for that cabinet (or was that where the 122As came from originally?)...

Regards,
Gordon.
mix and match, shake and bake, that's my thing :D