JBL L166 A woofer clarification (122A or 122A-1)

[jmchris01]

Reader for a couple years (just getting into vintage HiFi to relive my youth!), but first time posting.

I recently (finally) acquired a pair of JBL L166 A speakers, in their original boxes. Speakers are mint condition with refoamed woofers. However, the woofers looked slightly different. When I opened up the cabinets, one of the woofers is marked "122A", and the other is "126A". it seems obvious that the 126A woofer is not original. Which lead me to question whether or not the 122A is original, given that the speakers are "L166 A", which I thought would contain the 122A-1 drivers.

One Foilcal reads "Model L166" with Serial Number: 35088A
Other Foilcal reads "Horizon" with Serial Number: 32111A

The original boxes have the serial numbers listed with "A" in a circle next to the serial numbers. See the pics for confirmation.

I have read up on how the L166 A speakers with the 122A-1 drivers have an additional "inductor", which I presume, based on other posts, is the large electronic device mounted on the floor of the insider speaker box (see pics).

So here is my dilema... Assuming that both speakers have the inductor, should I replace both drivers with 122A-1 or 128H-1? Or should I simply replace the single 126A woofer with a 122A driver and call it a day? If I do the later, should I (is it recommended) that I bypass the inductor (assuming it is the device located on the floor of the speakers)?

Thanks in advance for your help!

[edgewound]

Reader for a couple years (just getting into vintage HiFi to relive my youth!), but first time posting.

I recently (finally) acquired a pair of JBL L166 A speakers, in their original boxes. Speakers are mint condition with refoamed woofers. However, the woofers looked slightly different. When I opened up the cabinets, one of the woofers is marked "122A", and the other is "126A". it seems obvious that the 126A woofer is not original. Which lead me to question whether or not the 122A is original, given that the speakers are "L166 A", which I thought would contain the 122A-1 drivers.

One Foilcal reads "Model L166" with Serial Number: 35088A
Other Foilcal reads "Horizon" with Serial Number: 32111A

The original boxes have the serial numbers listed with "A" in a circle next to the serial numbers. See the pics for confirmation.

I have read up on how the L166 A speakers with the 122A-1 drivers have an additional "inductor", which I presume, based on other posts, is the large electronic device mounted on the floor of the insider speaker box (see pics).

So here is my dilema... Assuming that both speakers have the inductor, should I replace both drivers with 122A-1 or 128H-1? Or should I simply replace the single 126A woofer with a 122A driver and call it a day? If I do the later, should I (is it recommended) that I bypass the inductor (assuming it is the device located on the floor of the speakers)?

Thanks in advance for your help!

The 122A-1 is the correct woofer. The 126A was used in the first version L65 Jubal.
122A-1 has no mass ring with Aquaplas on rear of cone.

122A has mass ring with bare cone.

The Tech Manual is unclear which model the inductor is in, but I'd surmise that it's in the first L166 model that has the 122A. The 122A-1 has declining midbass with the Aquaplas. It probably makes no difference with the inductor. The recone kit specified for the 122A is C8R129H that does have black Aquaplas on the rear of the cone, and was also the woofer used in the L65B.

[jmchris01]

The 122A-1 is the correct woofer. The 126A was used in the first version L65 Jubal.
122A-1 has no mass ring with Aquaplas on rear of cone.

122A has mass ring with bare cone.

The Tech Manual is unclear which model the inductor is in, but I'd surmise that it's in the first L166 model that has the 122A. The 122A-1 has declining midbass with the Aquaplas. It probably makes no difference with the inductor. The recone kit specified for the 122A is C8R129H that does have black Aquaplas on the rear of the cone, and was also the woofer used in the L65B.

I think it's the opposite from what you have quoted. The earlier L166 (non-A) did not have the inductor. The newer L166-A that replaced the L166 has the inductor necessary for the 122A-1 driver. That's what I gather from reading other posts.

Do you know if the "inductor" is the device mounted on the inside bottom of the cabinet as pictured? I've seen pics of the inside of other L166's that do not have that device, so I presumed that was the inductor that everyone references.

[edgewound]

I think it's the opposite from what you have quoted. The earlier L166 (non-A) did not have the inductor. The newer L166-A that replaced the L166 has the inductor necessary for the 122A-1 driver. That's what I gather from reading other posts.

Do you know if the "inductor" is the device mounted on the inside bottom of the cabinet as pictured? I've seen pics of the inside of other L166's that do not have that device, so I presumed that was the inductor that everyone references.

The inductor is the device mounted on the bottom of the cabinet.

Since the aquaplas rolls off the high-end of the woofer, and the inductor serves the same purpose at 6dB/octave...and the factory Tech Manual is clear as mud on the issue...it could be that the added inductor was an improvement to the overall sound of the system, with less phase interaction between the woofer and midrange. That sounds like a good answer...no?

Some things were not always documented to perfection, but much better than most companies.

[jmchris01]

The inductor is the device mounted on the bottom of the cabinet.

Since the aquaplas rolls off the high-end of the woofer, and the inductor serves the same purpose at 6dB/octave...and the factory Tech Manual is clear as mud on the issue...it could be that the added inductor was an improvement to the overall sound of the system, with less phase interaction between the woofer and midrange. That sounds like a good answer...no?

Some things were not always documented to perfection, but much better than most companies.

Yes, that makes sense. The inductor was not present in the original L166 speakers.

I don't think there is any harm in using the L166 122A woofer with the inductor, even though it was added to the "L166 A" to support the 122A-1 woofer. So my best bet may be to just replace the single 126A woofer with a 122A and leave the inductors in line. No need to try and replace them both with 122A-1 drivers.

[edgewound]

Yes, that makes sense. The inductor was not present in the original L166 speakers.

I don't think there is any harm in using the L166 122A woofer with the inductor, even though it was added to the "L166 A" to support the 122A-1 woofer. So my best bet may be to just replace the single 126A woofer with a 122A and leave the inductors in line. No need to try and replace them both with 122A-1 drivers.

Your best bet would be a 122A-1.

I can make you one if you happen to find a blown 122A. I might even have one 122A-1 that needs a resuspension. I'll look to see what I might have.