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View Full Version : Help needed on JBL 4333b



macster
11-24-2009, 10:06 AM
i bought one pair yesterday and i realised one side the super tweeter is total quiet, try changing cables and all but failed. Can someone tell me what may be the issue here and how do i open up the cabinet, do you have pics, could it be a connection lose or voice coil issue? all help greatly appreciated

speakerdave
11-24-2009, 10:22 AM
It could be a loose wire, but tweeters are sometimes burned out by high frequency distortion products when speakers are powered by an overdriven small amp.

Access to the 2405 is through the woofer hole. Lay the speaker on its back. Loosen the clamp bolts and remove the clamps. The woofer gasket will probably be stuck, unless it has been removed recently. Loosen it carefully with a thin putty knife or wall knife blade. Buffer the baffle with heavy paper or posterboard under the blade. Before you pick up the woofer prepare a spot to put it down. Since it will have wires connected to it, you will need to set it down briefly on the baffle while you disconnect the wires. Do not try to hold the woofer with one hand and disconnect the wires with the other. Put down a piece of heavy paper or poster board so you do not marr the baffle. Note the polarity before you disconnect the wires.

Check the connections to the tweeter. If they are tight, then you may have a burned voice coil. Demount the tweeter and do a resistance test with an ohm meter.

If any of what I have described here is beyond your usual capacity with tools, etc., it might be better to have the speaker serviced.

macster
11-24-2009, 10:04 PM
thanks, appreciate your description of how to remove the 2405. If its a damage voice coil what should i do? can VC be replaced and how to replace it? how much will it cost? how much will a replacement 2405 cost? Many thanks in advance

Mr. Widget
11-24-2009, 10:57 PM
If the voice coil is damaged you need to replace the entire diaphragm. Diaphragm replacement for the 2405 is a bit tricky but it can be done in the field. If you do several searches here you can find instructions on opening the driver and centering the diaphragm without wrinkling it. If there is an authorized JBL service center in Singapore, I'd recommend you take the tweeter to them.

Alternatively, these folks may sell and ship one to you, if it turns out that is what you need.

http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Product_Code=10-250&Category_Code=l_jbl_dias


Widget

macster
11-26-2009, 08:48 AM
hi thanks but did anyone get from this seller? Are they good?

http://www.youtube.com/user/SoundSpeakerRepair#p/a/u/1/POHs1n_PXX4

macster
11-28-2009, 11:08 AM
hi can anyone recommend a company that sells either an original or compatible 2405 diaphragm? thanks in advance. Should i get a compatible or an original diaphragm?

BMWCCA
11-28-2009, 12:06 PM
hi can anyone recommend a company that sells either an original or compatible 2405 diaphragm? thanks in advance. Should i get a compatible or an original diaphragm?Re-read the fourth post in this thread. No one here will recommend a non-JBL diaphragm but if that's what you want that same link will get you one of those, too.

macster
12-01-2009, 08:33 AM
thanks, apologies for asking compatible diaphragms, i am pretty new to this :)forum. While i decide which diaphragm i should get, can i feed in a 2402H (8ohms) to replace the faulty 2405? i will surely be replacing a pair of them as i bought this pair a while back but never get a chance to use it. Will this replacement be of any issue? any suggestions welcome, thanks guys !

Rolf
12-02-2009, 02:01 PM
Hi. Since (as I understand it) the problem did not move, but stays in the same channel, the problem may also be in the network?? Some work, but one way is to change the 2405's from L>R and R>L. If the "dead" 2405 then works it may be the network ?




It could be a loose wire, but tweeters are sometimes burned out by high frequency distortion products when speakers are powered by an overdriven small amp.

Access to the 2405 is through the woofer hole. Lay the speaker on its back. Loosen the clamp bolts and remove the clamps. The woofer gasket will probably be stuck, unless it has been removed recently. Loosen it carefully with a thin putty knife or wall knife blade. Buffer the baffle with heavy paper or posterboard under the blade. Before you pick up the woofer prepare a spot to put it down. Since it will have wires connected to it, you will need to set it down briefly on the baffle while you disconnect the wires. Do not try to hold the woofer with one hand and disconnect the wires with the other. Put down a piece of heavy paper or poster board so you do not marr the baffle. Note the polarity before you disconnect the wires.

Check the connections to the tweeter. If they are tight, then you may have a burned voice coil. Demount the tweeter and do a resistance test with an ohm meter.

If any of what I have described here is beyond your usual capacity with tools, etc., it might be better to have the speaker serviced.

speakerdave
12-02-2009, 08:04 PM
Yes, if the DCR seems OK, the next thing would be to isolate the crossover.

4343
12-11-2009, 09:06 AM
Are there not L-Pads on this model? So far I've seen no discussion of cleaning or at least rotating them to see if the problem clears up...

Also the link below states that the diaphragm fits 2405, 2404H and also 2404H-1, among others. I was under the impression that 2404H-1 used the the 2402 type diaphragm for better power handling. Is this not the case?

http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Product_Code=10-250&Category_Code=l_jbl_dias