My JBL 4343 repair story

[BMWCCA]

There's not really a huge output from those even in the cabinet when compared to the woofer and mid-bass drivers.

[pyonc]

The first is scheduled to open did not. But opened the baffle in order to see the situation from the internal crack is found. Removal of the woofer, removal of the front baffle is referred to as a daunting task in the 4343 owner our Japan　. I can open and easy for 30 seconds in the assistant help.


Attachment 73058

Attachment 73059


Hello guys nice to meet you !

Attachment 73060

Well done! How did you open the upper cabinet or enclosure?

[y60kuro]

There's not really a huge output from those even in the cabinet when compared to the woofer and mid-bass drivers.

Hi BMWCCA　
Thank you　info.　OK I understand . sometimes I hear alnico magnet reduce magnetize 5%/10year ,and any audio mania do re-magnetize here. They say reduce magnetize makes small sound .I am first time to have these JBL professional unit and dont know what is usual .thank you

Well done! How did you open the upper cabinet or enclosure?

Hi pyonc
Thank you coment. I done like this


1:remove all screw
2:remove 38cm unit
3ut jack on under upper baffle lower end
4:slowly up jack , easy to open upper baffle

[pyonc]

Hi BMWCCA　
Thank you　info.　OK I understand . sometimes I hear alnico magnet reduce magnetize 5%/10year ,and any audio mania do re-magnetize here. They say reduce magnetize makes small sound .I am first time to have these JBL professional unit and dont know what is usual .thank you



Hi pyonc
Thank you coment. I done like this


1:remove all screw
2:remove 38cm unit
3ut jack on under upper baffle lower end
4:slowly up jack , easy to open upper baffle

Nice job!
By the way, can you explain how you opened the L-Pad? It looks like you used something like hair dryer.
As a big fan of 4343, I'm curious. Thanks.

[y60kuro]

Nice job!
By the way, can you explain how you opened the L-Pad? It looks like you used something like hair dryer.
As a big fan of 4343, I'm curious. Thanks.

Hi Thanks man . Sorry I am poor English L-Pad is aluminum plate is oK ? Yes I used hair dryer to heat and Loosen warm a pressure-sensitive adhesive, it was peeled off slowly.　I　think to use heat gun first but I can do heir dryer .

[y60kuro]

Little progress

Add brace : all corners　 /　center (top,bottom, middle brace)

This such as an image of the reinforcing fixing of front baffle and adhesion reinforcement of the every corners.　Is this produce good results, is or not I do not know.Better to mood reinforced is the idea say it would be good.



Also reinforced in the same way as the other side.

[pyonc]

Hi Thanks man . Sorry I am poor English L-Pad is aluminum plate is oK ? Yes I used hair dryer to heat and Loosen warm a pressure-sensitive adhesive, it was peeled off slowly.　I　think to use heat gun first but I can do heir dryer .

Yes. Did you clean the L-pad inside?
You see the three volume control knobs(UH, M, LF), and I mean, clean them inside.
You're strongly recommended to remove any possible scratch noises.

[y60kuro]

Yes. Did you clean the L-pad inside?
You see the three volume control knobs(UH, M, LF), and I mean, clean them inside.
You're strongly recommended to remove any possible scratch noises.

Hi pyonc
No I have not done yet but I will clean it next step after box repair . my 4343 is long time sleeper old girl I agree you said thank you.

horrible

[pyonc]

Hi pyonc
No I have not done yet but I will clean it next step after box repair . my 4343 is long time sleeper old girl I agree you said thank you.

horrible

Can you show some more pictures of them? It looks a bit rusty already... Thanks.

[BMWCCA]

Looks like the bi-amp switch to me, but then I don't have one on my 4345s and that's not the greatest photo!

[y60kuro]

Can you show some more pictures of them? It looks a bit rusty already... Thanks.

Hi pyonc I have L pad pic is just only this . L-pad seem to be replaced once already but over 10 years sleeping 4343 ok I will maintenance it inside thank you every time .

Looks like the bi-amp switch to me, but then I don't have one on my 4345s and that's not the greatest photo!

Hi BMWCCA Yes this is bi-amp selector SW it is so ripen by 40 years time . I think I will off this or make terminal for direct thank you again.

[pyonc]

Hi pyonc I have L pad pic is just only this . L-pad seem to be replaced once already but over 10 years sleeping 4343 ok I will maintenance it inside thank you every time .







Hi BMWCCA Yes this is bi-amp selector SW it is so ripen by 40 years time . I think I will off this or make terminal for direct thank you again.

Nice picture. I look forward to the final outcome of your repair job at the moment.

[BMWCCA]

Hi BMWCCA Yes this is bi-amp selector SW it is so ripen by 40 years time . I think I will off this or make terminal for direct thank you again.

Just bi-amp and forget the switch. You'll never regret it.

[y60kuro]

Nice picture. I look forward to the final outcome of your repair job at the moment.

Hi pyronc thank you. I think I want to finish repair box till winter because we have sow here ,this winter I want to stay 4343 in the warm my room . unit and crossover network can repair in the room . it is good to reading Haruki Murakami novels with 4343 sound

[y60kuro]

Just bi-amp and forget the switch. You'll never regret it.

Hi BMWCCA OK I will go bi-amp how it goes I am very look forward to . I think upper 3way (2405+2420+2121) is ALTEK 1520 type tube , 15inch unit is marantz solid state amp with marantz 7T or model 3300 or SC-9 .