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Dr.db
09-06-2016, 01:11 PM
Hi volks,

Jbl seems to wire their speakers in a weird manner. Positive connects to black...
So if i want to replace their diaphragm with a radian, how do i have to connect these?
There is a red dot on the radians, do i have to connect radian-red to Jbl-black?

Thanks a lot for your help,
Olaf

JeffW
09-08-2016, 06:45 AM
It's not all drivers, some are red to positive. The 2445 isn't on the JBL list, but some of the later drivers are, so I'm not sure it's black to positive, anyway.

http://www.jblpro.com/pub/technote/tn_v1n12b.pdf

The best thing would be to measure it after installation, just to make sure.

Dr.db
09-08-2016, 11:27 AM
The jbl is black to positive...

But what is the radian.??

gdmoore28
09-09-2016, 02:37 PM
The jbl is black to positive...

But what is the radian.??

The Radian drivers are RED to POSITIVE.

Chevelle
09-10-2016, 10:48 AM
Hello Olaf,

just do a simple test:

1. connect the diaphragm to the red and black terminals

2. place the diaphragm into the slot of the poleplate but do NOT fix it with the 8 screws, keep it loose in the slot

3. connect a 1.5volt battery to the terminals, positive battery to the RED terminal

4. connect the negative battery very short to the BLACK terminal and watch the diaphragm:
if it jumps OUT of the poleplate you have connected it the right way,
if it wants to jump more INTO the poleplate you have to reverse the terminals.

Good luck

Hjalmar

Chevelle
09-10-2016, 10:55 AM
Hallo Olaf,

sehe gerade das du auch in Germany wohnst, hoffe du kannst was mit meiner englischen Erklärung anfangen, sonst auch gerne in Deutsch.....

Gruß aus Hannover

Hjalmar

BeDome
09-11-2016, 03:20 AM
One other thing I have learned over the years is that when determining polarity of unknown compression drivers and you do not have them apart because the work great, place a fine tape like packing tape, over the exit (good idea anytime they are off the horns, anyway) and then do the battery procedure. The light tape will still move slightly, enough to see or feel.

Dr.db
09-12-2016, 06:31 AM
Hi,

thanks a lot for your help!

I knew the battery test, but I have only used this with woofers so far. I was afraid it would hurt a compressionsdriver....

But anyway, the Radians are red to positive. So they have to be reversed when installed in the jbl´s.

Radian red to jbl black.

Chevelle
09-12-2016, 08:31 AM
My Radian dias 1225 for the 2420/21 are NOT positiv on red. Radian says that their replacement dias for JBL drivers have the same red mark as the original so it is easier to change. So the red mark on Radian is the same as red mark on JBL. The Altec replacment dias from Radian are of course positiv on red.

Hjalmar

Chevelle
09-12-2016, 08:51 AM
You can read it here:

http://www.parts-express.com/pedocs/specs/manufacturer-specifications-44925.pdf

"...with the same polarity as the original"

gdmoore28
09-12-2016, 12:24 PM
My error for not reading your original post closely enough. I thought you were referring to a Radian DRIVER rather than a diaphragm. Thanks to the others for catching my mistake.

GeeDeeEmm

Dr.db
09-12-2016, 02:37 PM
Thanks a lot for that very important notice!!

So I believe the 1,5v batterie test remais the only true test.

But it realy doesn`t hurt the diaphragms :confused:
I thought this was only possible with woofers, as the cone movement could be way to much for the compression-drivers!?

Chevelle
09-12-2016, 10:08 PM
I have phase tester with sender and receiver so I check every driver after changing the diaphragm for correct phase. I do it every time to be sure. I never had a Radian diaphragm for JBL drivers that was positiv on red, always negative same as original dias.

As long as you take a 1.5 volt battery and only connect it very short to the terminals to hear that "clic" sound and watch it move it does not hurt the diaphragm. I did that hundred times.

Hjalmar

Dr.db
09-13-2016, 02:39 AM
As long as you take a 1.5 volt battery and only connect it very short to the terminals to hear that "clic" sound and watch it move it does not hurt the diaphragm. I did that hundred times.

Hjalmar

Allright, I´ll do that.

Thanks a lot!