Jump to content

Sign in to follow this  
Tubularbells

JBL 4435 crossover update

Recommended Posts

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...

post-122789-0-37819700-1468226198_thumb.

post-122789-0-68973900-1468226237_thumb.

post-122789-0-43963300-1468226291_thumb.

post-122789-0-94144800-1468226350_thumb.

post-122789-0-86931200-1468226384_thumb.

post-122789-0-64603800-1468226431_thumb.

Share this post


Link to post
Share on other sites

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?

Share this post


Link to post
Share on other sites

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?

 

 

post-122789-0-05702100-1468227557_thumb.

post-122789-0-42081200-1468227692_thumb.

Share this post


Link to post
Share on other sites

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)

Share this post


Link to post
Share on other sites


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.

Share this post


Link to post
Share on other sites

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

post-122789-0-44507800-1468395385_thumb.

Share this post


Link to post
Share on other sites


Maybe she just likes you ;)

I guess your busy with the soddering iron.

 

Ha  maybe.

 

Thanks again for the awesome service mate  :thumb:

Share this post


Link to post
Share on other sites

Or maybe she just wants to be squeeeezed to help you de stress :)

 

No problemo :)

Share this post


Link to post
Share on other sites

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. 

 

 

post-122789-0-70123300-1468793754_thumb.

post-122789-0-34891100-1468793805_thumb.

post-122789-0-66759700-1468793834_thumb.

post-122789-0-09023400-1468794108_thumb.

post-122789-0-80495300-1468794135_thumb.

post-122789-0-79600000-1468794165_thumb.

post-122789-0-77995100-1468794200_thumb.

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites


Getting there....

post-122789-0-61422700-1468817398_thumb.

post-122789-0-71771600-1468817597_thumb.

Edited by Tubularbells

Share this post


Link to post
Share on other sites

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.

post-122789-0-18332200-1468916893_thumb.

post-122789-0-54848400-1468916957_thumb.

Share this post


Link to post
Share on other sites

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

 

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

Share this post


Link to post
Share on other sites

@@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  ;)

Share this post


Link to post
Share on other sites


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

 

Ha ha - nah just teasing you, a friend in need is no friend indeed !  :P

 

A week is a long time in this game, have oscillated from this to that in my mind but give up a (lesser) classic like yours???

 

Not likely !   :unsure:

Share this post


Link to post
Share on other sites

Very neat. Me likey.

 

The superior caps are 'broken in' before they are allowed to leave the factory.

But they will improve a little more with use.

The standard-z caps will need to break in, but im guessing their in a parallel section so shouldn't be a big factor.

Share this post


Link to post
Share on other sites

So it's been nearly a week since the upgrade and am happy to report that the upgrade was definitely worthwhile. In fact id almost say its a bigger improvement than my recent upgrade to a Cadenza Black cart from a $400 AT.

 

So the first thing that jumps out is how much extra volume there is. I now have my amp 5 clicks down from where I used to have it for approx the same volume so i'm thinking that evil internal/external crossover selector switch was highly resistive judging by the amount of black carbon on it  or perhaps it was all those crappy spade connectors used in the wiring. Either way it improvement is not subtle.

 

I have also noticed a significant increase sense of dynamics and transparency and the bass seems to go lower as well.

 

All in all not a bad improvement for less than $400! A truly worthwhile project for those running 20+yo speakers imo.

 

 

post-122789-0-43786300-1469424449_thumb.

Share this post


Link to post
Share on other sites
Guest

Nice work, well done.  :)

Share this post


Link to post
Share on other sites

Awesome.

Very glad your happy with the result.

 

Suprised by the 'increase of volume'. I'd wonder if that isnt more to do with the new point to point wiring and cable over the old wire and pcb tracks ?

My experience is by 'fixing' the layout and connection wiring etc, you gain in every area.

 

If you want to go further.

 

deeper tighter bass, use a c coil for the bass section.

smoother mid and treble go for  wax coil (or a foil coil or the new litz wax coils) in the mid and tweet section.

more detail, use a silver cap or alumen cap for the tweeter.

Share this post


Link to post
Share on other sites

..Um, what's a "c coil" please?

Share this post


Link to post
Share on other sites

A c-coil is a toroidal inductor.

Uses the same technology as toroidal transformers.

Circular core with windings wrapped around that.

Result is very low radiated field, very very low dcr, massive power handling.


 

Stock pic, real units have a thick plastic sleeve on them.


 



 

C-Coil.jpg

 

 

EDIT.

You see one in use top left of these crossovers.

 


 

Edited by Green Wagon

Share this post


Link to post
Share on other sites

C Coil is particularly suited in the bass section of a cross over 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Classifieds Statistics


    Currently Active Ads

    Total Sales (Since 2018)

    Total Sales Value (Last 14 Days)

    Total Ads Value (Since March 2020)
  • Recently Browsing   0 members

    No registered users viewing this page.


×
×
  • Create New...