Jbl 4348

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06-22-2010, 02:24 PM
hlaari

Jbl 4348

Can someone help me help me
I am lookin for JBL 4348 lowfreq crossover network.

Regards
Ari Oskarsson
06-22-2010, 03:46 PM
Robh3606

Here you go

Rob:)

http://www.audioheritage.org/vbullet...php?17053-4348
06-22-2010, 04:35 PM
hlaari

Quote:

Originally Posted by Robh3606

Here you go

Rob:)

http://www.audioheritage.org/vbullet...php?17053-4348

Thanks for the information

I think at both coils are air coils 2.8 mh and 8.2 mh
the problem is I need someone to make the coils for my accurately the same like the orginal
I need pair of both

regards
Ari
06-22-2010, 05:20 PM
Robh3606

Quote:

I think at both coils are air coils 2.8 mh and 8.2 mh

No they are not. Take a look at the Tech Sheet. They are definately cored. Take a look at the ERSE coils they have very low DCR for there values and are readilly available.

Rob:)

http://manuals.harman.com/JBL/HOM/Te.../4348%20ts.pdf
06-23-2010, 12:12 AM
hlaari

Quote:

Originally Posted by Robh3606

No they are not. Take a look at the Tech Sheet. They are definately cored. Take a look at the ERSE coils they have very low DCR for there values and are readilly available.

Rob:)

http://manuals.harman.com/JBL/HOM/Te.../4348%20ts.pdf

I find a pictures of the 4348 low network and I dont se any metal in the center of the both coil, they are not C-coil?

Regards
Ari
06-24-2010, 04:08 PM
hlaari

Take a look at the ERSE coils they have very low DCR for there values and are readilly available.

Rob:)

I look on the ERSE homepage and ask them about the coils I need for the crossover, but they have not answer me.

Regards
Ari
06-24-2010, 07:31 PM
grumpy

1 Attachment(s)

Attachment 46491

Schematic shows iron/laminate core, but the picture at the Japanese/Harman site
sure looks like air core :)

Wouldn't be the first time that a prototype photo -or- a schematic error
made it into publication... or a production change didn't match an old picture... or ...

I'd -think- a lower-loss inductor would make sense here, but I'm not about
to criticize whatever the designer intended. Might have to ask someone to pop
open their 4348 for you... :dont-know:
06-25-2010, 12:23 AM
hlaari

Quote:

Originally Posted by grumpy

Attachment 46491

Schematic shows iron/laminate core, but the picture at the Japanese/Harman site
sure looks like air core :)

Wouldn't be the first time that a prototype photo -or- a schematic error
made it into publication... or a production change didn't match an old picture... or ...

I'd -think- a lower-loss inductor would make sense here, but I'm not about
to criticize whatever the designer intended. Might have to ask someone to pop
open their 4348 for you... :dont-know:

I have find more pictures of the 4348 low crossover network and both coil looks like air core.

regards
Ari
06-25-2010, 01:50 AM
Ian Mackenzie

Not all the PCB are shown.

There are 10 chokes and I dont see that many in the image.

Typcially JBL allows for a total dcr of around 0.6 ohms in the woofer low pass sections. So select you components accordingly.
06-25-2010, 06:41 AM
grumpy

Look harder... they're there.
It would be easier if a microscope weren't needed with that image :)

Matches the assembly numbers 12, 13 on the tech sheet pdf as well
(one HF assy, one LF assy)
06-25-2010, 04:13 PM
Ian Mackenzie

I guess I need new glasses or they are tiny chokes....LOL
06-28-2010, 11:59 PM
hlaari

JBL 4348 crossover

I send email to Harman Audio in Japan and ask them about the coils in the lower crossover network, they told me at the both coils 2.8mh and 8.2mh are air core coils :)

regards
Ari
06-29-2010, 07:58 AM
Ian Mackenzie

I really does not matter if the coil is designed correctly.