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Mctwins
05-09-2014, 03:48 AM
Hallo!

I would like to know what the Nominal Impedance is for the Woofer and HF/UHF respectivly in JBL 4429.

Can't find any info on this.:dont-know:

pos
05-09-2014, 04:05 AM
The woofer is the 8ohm version of the 1200Fe:
http://www.audioheritage.org/vbulletin/showthread.php?21713-1200fe-8

8 ohms nominal, 5.6 ohms DCR

Mr. Widget
05-09-2014, 09:36 PM
The woofer is the 8ohm version of the 1200Fe:
http://www.audioheritage.org/vbulletin/showthread.php?21713-1200fe-8

8 ohms nominal, 5.6 ohms DCRAll very well, but to answer his question the curve needs to be generated with the drivers in the 4429 cabinet.
You should be able to get a Woofer Tester 2 shipped to Europe at a fairly reasonable rate... they are a snap to use and you would have your answer.


Widget

Mctwins
05-09-2014, 10:28 PM
The woofer is the 8ohm version of the 1200Fe:
http://www.audioheritage.org/vbulletin/showthread.php?21713-1200fe-8

8 ohms nominal, 5.6 ohms DCR

Thanks, I saw this before, but, dosen't the network has to be taken into account as well. 5.6 ohm must be without the network.


All very well, but to answer his question the curve needs to be generated with the drivers in the 4429 cabinet.
You should be able to get a Woofer Tester 2 shipped to Europe at a fairly reasonable rate... they are a snap to use and you would have your answer.


Widget

About woofer tester, I will check it out, but, I agree with you here that it must include the cabinet and also with the network.

It say in the technical manual....

DC resistance:

Low-Frequency Transducer 5.6 ohm +/-10%

High-Frequency Transducer 3.7 ohm +/-10%

Ultrahigh-Frequency Transducer 5.6 ohm +/-10%

Reason for me to know is that I would like to bi-amp with my MC252 and to know what tap to use.

I mean, DCResistance is not the same as nominal impedance, right.:confused:

Mr. Widget
05-09-2014, 11:13 PM
Reason for me to know is that I would like to bi-amp with my MC252 and to know what tap to use.Choosing the correct tap is actually fairly subjective. You should try a couple of taps and see what sounds the best to your ears in your system.



I mean, DCResistance is not the same as nominal impedance, right.Did you look at the last plot in the link that Pos posted? That is the free air impedance of the woofer... it looks nothing like a DCR measurement.

BTW: You are right about the network it will also affect the impedance curve, as will the horn, the baffle, and the enclosure.


Widget

Mctwins
05-10-2014, 11:46 PM
Hallo!

I have read the linked Pos gave and on "Engineering Test Specification" 4. Impedance(Ref only) it say's that the woofers Rated Impedance is 8 ohms and Min.Impedance is 7.5 ohms. Still no meantioned about network involved and so on.

I know that it is not so trivial what ohm tap I use and that I can test to hear what sounds best but it would be nice to know for sure.

Search continous....

Thanks