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Tubularbells

JBL 4435 crossover update

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Following on from the JBL 4411 refresh thread ive decided to give my JBL 4435's a bit of an internal refresh as there pushing over 20 years old now. Key was I am able to return to stock at any time should the need arise so will be building a new board (with new wiring) that can be swapped in. After much reading I have also decided to use all existing inductors as these were the real "unknown" with not only inductance but also DCR to get right otherwise id potentially screw up the crossover points.

 

Im also keeping both tweeter L-pad and mid level pad's fully functional (even though im not using them) 

 

Parts are ordered via Spesarkerbug so should be here within the week.

 

Biggest difference I reckon will be the removal of the internal/external switch which as you can see via the pics below the conductors have tarnished and with full power (in my case up to 800w) going through those tiny contacts!

 

So heres some pics of the stock crossover. Note the Mexican caps! As much as I enjoy a good Tequila and burrito im sure these guys are not the audio capital of the world...

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Hope the build goes well mate, those rotary switches are notorious for degrading the sound.

 

While the modern caps will be light years ahead those caps wouldn't have been too bad at the point of manufacture, at least they are all poly caps. The inductors are made in mexico too.

 

What caps did you end up going with?

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So I was in Bunnings (as I am every Sun morning with the young bloke as they have a kids craft session and I can aimlessly wander the aisles and buy crap i don't need) and saw this 1mm solid core copper wire for 65c a meter.

 

Seeing as my JBL's have some nasty looking stranded stuff in there that might even be aluminium wire (according to a brochure I have) do you think its worth using as part of this re-fresh?

 

 

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Hope the build goes well mate, those rotary switches are notorious for degrading the sound.

 

While the modern caps will be light years ahead those caps wouldn't have been too bad at the point of manufacture, at least they are all poly caps. The inductors are made in mexico too.

 

What caps did you end up going with?

 

Jantzen Superior for all but parallel bass caps which will be Jantzen Standard Z cap.

 

So nothing too exotic as frankly I don't think the rest of my system warrants it however it  should be a nice upgrade nonetheless (have used Superior Z caps in previous upgrades in Zu speakers and phono pre-amps with positive results)

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I'd be tempted to keep the factory wire.

Being multi strand it will have better flexibility.

Solid core can be a b to work with as without warning it can break.

If you really want to replace it, I'd use the jantzen silver plated 16awg. Yes yes, but no im not trying to 'sell' you on it, just that it really is a nice cable to work with.

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So this arrived today and by the looks of it, it's glad to be here  :P

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Maybe she just likes you ;)

I guess your busy with the soddering iron.

 

Ha  maybe.

 

Thanks again for the awesome service mate  :thumb:

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A little progress. One speaker has been gutted and now comes one of the hardest parts, arranging the new components on the new board on an orderly fashion. I haven't built a crossover in probably 10 years so am a little rusty but my first step is to arrange components onto a piece of paper while referencing the circuit diagram to mark where each of the connections should be.

 

Once I have got it right it's then a easy process of taking a photo and using it as a guide when mounting onto the final mdf boards. 

 

 

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Awesome pics.

 

And here I was thinking you were just going to swap out the caps and resistors on the existing board..

Hurry up will you, I can't wait to see this progress :D

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And they're done! 

 

Just hooked them up and am testing as we speak.Luckily I seemed to have traced the circuit correctly as the divider networks appears to be crossing over in the right places and everything is sounding 'right'. i'll give it a decent run before I comment whether I hear any improvements but sounds VERY promising so far.

 

Pic below shows one completed and the other still in progress.

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@@Tubularbells - excellent work !!!  :thumb:

 

Might have a job for you with the Yammies crossovers ! :P

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@@Tubularbells - excellent work !!!  :thumb:

 

Might have a job for you with the Yammies crossovers ! :P

 

Mate happy to help you out but I thought you were getting rid of them  ;)

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