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View Full Version : L100t crossovers?



annamarykahn
11-05-2010, 01:11 PM
Couldn't come up with a better title, sorry :o:

Anyways, I have 2 L100t crossovers, but they have different part numbers. One is JBL PN 66422, the other is 66426. From a visual inspection the only differences are R2 and R3. Looks like the values are 3.9 and 15 Ohm respectively. Don't know if the inductors are the same, though. From looking here, I wasn't able to find any information relating to the 66422, only the 66426.

Curious if anyone has run across this?

FYI I purchased the 66422 off of ebay. Might they be from a L100T with a different midrange driver, or for a different speaker altogether?

Hoping someone might have some insight.

Thanks!

Maxwelhse
11-09-2010, 05:59 PM
Couldn't come up with a better title, sorry :o:

Anyways, I have 2 L100t crossovers, but they have different part numbers. One is JBL PN 66422, the other is 66426. From a visual inspection the only differences are R2 and R3. Looks like the values are 3.9 and 15 Ohm respectively. Don't know if the inductors are the same, though. From looking here, I wasn't able to find any information relating to the 66422, only the 66426.

Curious if anyone has run across this?

FYI I purchased the 66422 off of ebay. Might they be from a L100T with a different midrange driver, or for a different speaker altogether?

Hoping someone might have some insight.

Thanks!

This probably won't be the most helpful answer, but as far as I know the L100T was only offered with the 104H-2 midrange driver. The L100T3 had the 104H-3 which, as I understand it, just had a different finish on the basket face. The 104H is a very slightly different animal and was offered in a host of other speakers, including the 240Ti/250Ti.

sperkerchef
11-09-2010, 09:21 PM
This probably won't be the most helpful answer, but as far as I know the L100T was only offered with the 104H-2 midrange driver. The L100T3 had the 104H-3 which, as I understand it, just had a different finish on the basket face. The 104H is a very slightly different animal and was offered in a host of other speakers, including the 240Ti/250Ti.

The L100T and L100T3 both used the 104H-2 as their mid-range driver. The 104H-3 is the superior mid-range of the two however it was used in the 4312A LR and the 4312C.

annamarykahn
01-09-2011, 11:29 AM
Does anyone know what the JBL PN 66422 crossover is from?

Thanks!

amk

HCSGuy
01-09-2011, 02:14 PM
Techbot says L80t

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L80T%20ts.pdf

annamarykahn
01-09-2011, 02:48 PM
thx HCSGuy!

amk

4343
01-09-2011, 09:12 PM
Techbot says L80t

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L80T%20ts.pdf

If you compare the schematic on the above link to the schematic here:

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L100t%20ts.pdf

you will see that the two resistors R2 & R5 (not R3) are the only differences in the mid and high portions of the two crossovers. This is to adjust the output levels to match the different sensitivities of the woofers.

Look closely and you'll notice that L1 is also different, 3.00mH for L100T, 2.2mH for L80T. This sets the low pass frequency on the woofers slightly different as well.

My L100T's have had the crossovers re-worked to the T3 spec. I used the boards and all the inductors that were the correct values, replacing L1, L2 and all the caps, plus a couple of resistors.

It would be possible to use the L80T board the same way, as the inductors you keep are the same.

duaneage
01-15-2011, 05:51 PM
I've reworked numerous L100T crossovers to L100T3 specs. There are at least three versions of the original L100T network, two on PCB and one with wire posts, and all have the same part number.

I rewind the coils to new specs and verify the new value is spot on. many crossovers were up to 10 percent too small so this alone made a huge improvement when reworked.

I still do this from time to time for a nominal fee to Lansing Heritage members, I did 4 sets last year.