Replacing Binding Posts on 250Ti

[bradster56]

It's been 30 years...Any suggestions? looking at WBT and Cardas for the transplant...Do I need short or longs posts I guess is the 1st question..Any insights/suggestions/comments? All and any gladly welcomed...Thanks!

[bradster56]

It's been 30 years...Any suggestions? looking at WBT and Cardas for the transplant...Do I need short or longs posts I guess is the 1st question..Any insights/suggestions/comments? All and any gladly welcomed...Thanks!



Nobody?

[grumpy]

Have you peeked behind the curtain? The binding posts -appear- to be soldered directly to the crossover circuit board.

You'll need some info to decide 1) if it's worth it to you (unless they are broken, changes will likely be cosmetic or placebo and could reduce the system value if not executed well/properly), 2) your electronic and mechanical skills are up to it, 3) how to obtain dimensions for potential replacements.

81449


81450

[rdgrimes]

I've used these Dayton posts (https://www.parts-express.com/dayton-audio-bpa-38sn-hd-binding-post-pair-satin-nickel--091-1247) on a few models, but not on a 250. My only requirement is that they not stick out past the MDF back plate where they can get bumped. These meet that requirement.

81451

[SEAWOLF97]

I have 250Ti's and considered replacing the posts as they would NOT take
12 ga. speaker wire.

Thought abt enlarging the hole that runs thru the posts, but that seemed risky.
then looked at access and whether they were soldered to the crossover and decided

just to use bananas and go on to other projects.

"If it ain't broke, fix it 'till it is"

[BMWCCA]

Looks like they're perfectly set-up for these Neutrik dual bananas:

http://audioheritage.org/vbulletin/attachment.php?attachmentid=42820&d=1258163589

[Ian Mackenzie]

Unless you were planning on building new charge coupled networks (has been done before) leave them well alone.

Phil’s suggestion looks like a great solution.

[bradster56]

Have you peeked behind the curtain? The binding posts -appear- to be soldered directly to the crossover circuit board.

You'll need some info to decide 1) if it's worth it to you (unless they are broken, changes will likely be cosmetic or placebo and could reduce the system value if not executed well/properly), 2) your electronic and mechanical skills are up to it, 3) how to obtain dimensions for potential replacements.

81449


81450


My rear panel looks nothing like that....I have one of the earliest L-250's sold and a few years after my purchase JBL made available a kit that I purchased to upgrade them up to the Ti series...

[BMWCCA]

My rear panel looks nothing like that....I have one of the earliest L-250's sold and a few years after my purchase JBL made available an kit that I purchased to upgrade them up to the Ti series...


Well then . . . I mean well, then: :useless:

[rdgrimes]

My rear panel looks nothing like that....I have one of the earliest L-250's sold and a few years after my purchase JBL made available an kit that I purchased to upgrade them up to the Ti series...

Likely then you have pretty much the same Masonite boards that the L250 has, with all the shorting bars on the back? And you already have experience with removing and replacing them. Personally I wouldn't bother unless the current posts are not functioning as they should. (or if I needed to take them out for some other reason) If you still have the original L250 boards, I bet they have the same setup and you can experiment on them.

[bradster56]

Yes it has the shorting bars...Original board is long gone...I'm certainly not comfortable or qualified to undertake this mission...The original posts are cheaply made and these classics deserve better :)

[rdgrimes]

Yes it has the shorting bars...Original board is long gone...I'm certainly not comfortable or qualified to undertake this mission...The original posts are cheaply made and these classics deserve better :)

I'm not sure I agree with the "cheaply" part, especially if they are still working after all the years.
The shorting bars are more likely to cause issues and need to be removed and cleaned periodically.

[Ian Mackenzie]

I would just clean them appropriately.

If you were going to spend money on better posts then it’s a logical step to build a new network and use charge coupled crossover to improve the overall resolution. That had been done before to great effect.

It’s not that difficult to build a new network. It just takes time and money 💰.

[bradster56]

Yes they still function as designed but when compared to offerings by WBT or Cardas they fall way short in my opinion...I certainly cannot do any upgrades with my skill level and it's not as though I can box them up and ship them to somebody qualified...Now if I could find somebody local...

[Ian Mackenzie]

I get it.

If you search l think a new charge coupled 250 Ti network was built by forum members before.

My point was unless you increase the resolving power of the network the audible value of the WBT connectors is academic.

[SEAWOLF97]

I'm not sure I agree with the "cheaply" part, especially if they are still working after all the years.
The shorting bars are more likely to cause issues and need to be removed and cleaned periodically.

>>"I'm not sure I agree with the "cheaply" part"
+1

I also made "shadow" shorting bars by tracing them on a copper sheet, cutting them out and "sandwiching" them under the stock bars. TO ME the bass improved a bit.

to OP: worry more about the HF foam plugs.

[bradster56]

Crossover upgrade was never in my sights to be honest...For me financially it would be a no-go but less than $500 or so to replace posts was within my budget...I have invested many thousands over the years in my system but left the speakers alone...BTW I have never touched the shorting bars (Is that a bad thing?)

[rdgrimes]

BTW I have never touched the shorting bars (Is that a bad thing?)

Remove them, clean them up on both sides with some steel wool and replace, snug them down.

[bradster56]

Good idea...I'm gonna do that now :)

[bradster56]

0000 steel wool did the job very nicely...

[SEAWOLF97]

couple of years ago I bought an extra set of 250ti's. one had loose binding posts , you would turn
the tightening knob and the whole thing would turn.

I don't recall if the posts were soldered to the xover, but I did open them (remove LF driver first) and hold the posts stationary from the inside while turning them from the backside.
(allen wrench through the wire insertion hole)

have to do that maneuver with the cabs laying on their sides. :eek:

[bradster56]

No loose binding posts yet...I want a pair of custom crossovers and WBT binding posts for under 1K :D

[SEAWOLF97]

I want a pair of custom crossovers

what issue are you trying to solve with the idea of custom crossovers ?

IF it's the highs are somewhat harsh, there is a much easier solution and cost next to nothing.
This has been addressed many times on this forum.

Your HF's are old enough that I almost guarantee that the foam plug is rotted. A normal problem
with 044's and 044Ti's.

[Robh3606]

No loose binding posts yet...I want a pair of custom crossovers and WBT binding posts for under 1K :D

Whatever you do don't let some "custom" builder talk you into them. That is a complex crossover and is specifically tailored for that driver set. If you change the voltage drive you will essentially ruin them. If the guy builds from the original schematic fine but don't go with a "Oh I can do better than that" If the guy uses the original network and plots the voltage drives and any modifications match the original voltage drive then you would be OK.

Rob:)

[gmarascortt]

couple of years ago I bought an extra set of 250ti's. one had loose binding posts , you would turn
the tightening knob and the whole thing would turn.

I don't recall if the posts were soldered to the xover, but I did open them (remove LF driver first) and hold the posts stationary from the inside while turning them from the backside.
(allen wrench through the wire insertion hole)

have to do that maneuver with the cabs laying on their sides. :eek:


All of my binding posts are loose and wobbling:eek: I just thought I would have to pull everything out to repair and/or replace. I purchased some copper Cardas posts about a year ago, but I have been fretting the task. So thanks for posting the much easier solution!:applaud:

[SEAWOLF97]

250Ti, 18Ti

from your tagline. I went the same route , picking up 18's as 044Ti insurance after buying the 250's. I didn't much care for their sound and they stay in their box (just, in case)

BUT then, I found some 120Ti's, cheap. They are likely the most undervalued JBL 3 way, 12 incher.
They've become my daily drivers, and IMHO the second best JBL 12 inch bookshelf (second only to the $5k Century Golds)

I put a fair amount of time into restoring the 120's and it was worth every minute. :D

[gmarascortt]

from your tagline. I went the same route , picking up 18's as 044Ti insurance after buying the 250's. I didn't much care for their sound and they stay in their box (just, in case).





I purchased those 18Ti's for $25.00 at a pawn shop in 1987. At the time, no consideration for the value and scarcity of the 044's. They were just thought of as my 250Ti's "little baby's" by my roommates in college! :D

[bradster56]

what issue are you trying to solve with the idea of custom crossovers ?

IF it's the highs are somewhat harsh, there is a much easier solution and cost next to nothing.
This has been addressed many times on this forum.

Your HF's are old enough that I almost guarantee that the foam plug is rotted. A normal problemwith 044's and 044Ti's.


No problems with the tweeters...Nice clean extended highs...I was thinking an updated audiophile crossover would further improve the quality of sound...

[Ian Mackenzie]

You are better off googling the question

Jbl L250 charge coupled

https://www.stereo.net.au/forums/topic/111495-jbl-250ti-charge-of-the-capacitor-brigade-d/

That is quite an insightful link of the whole topic. Interestingly it’s on Stero.net.au

[Ian Mackenzie]

Here is the original LH thread

http://www.audioheritage.org/vbulletin/showthread.php?3427-Building-biased-250Ti-networks

[bradster56]

Thank you Ian,a very informative thread to be sure...I now know this whole crossover thing is way above my pay grade ;)

[SEAWOLF97]

Thank you Ian,a very informative thread to be sure...

his link also had pics that should answer your Q about binding posts soldered to xover or not

[bradster56]

I'm realizing these are issues are beyond my personal involvement and and I doubt I can find someone qualified who makes house calls LOL! No way I want to lug these brutes to a shop or an individual even if I could locate one within a reasonable distance to work on these babies...

[LarryM]

Close up of the back-side of binding posts. Looks like a 3/8" nut. Taking them out would require you to unsolder the wires. If loose, they should only turn a few times as the wires will wrap around until....

[bradster56]

Beautiful! Thank you for the tutorial...My stock posts are very tight indeed.. thought changing the binding posts to a more audiophile version would be less complicated but so goes life..Remove the woofer,then the crossover board,unsolder the existing posts,solder the new posts (Long or short posts needed?) and hope everything fits perfectly (Doubtful) A no-can-do with my skills :D Now if I can get someone to make a house call i'll stock the fridge with their favorite beer (or beverage of their choosing) I may even throw in some cash ;)

[Ian Mackenzie]

There has to be someone in your region surely?

Okay this is a way of validation of the money and effort

Run a cable through a port and solder to the spade connector or the Jbl binding post or the pcb.

Ask a friend to help do a double blind test to compare the external cable to the internal cable connection with the Jbl binding post.

If you can detect a positive change then you have the green light.

If not shelve the idea.

My suggestion having messed with these types of issues over the years is no one improvement will do it. You need to look critically at what else is relevant to the quality of the signal getting to the drivers. I refer to it as a systems approach.

My suggestion is build or get help to build a charge coupled network. That will impact in a positive way and make putting in better posts more worthwhile. I would build a board for each filter and run a separate cable from the amp for each filter. The crossover network could be external just to annoy your wife but it would be a conversation piece

A good post is about a good conductor electrically and sufficient surface area and contact pressure to pass the current. I like Cardas posts. Use quality ofc cable of appropriate gauge.

There is extra potential in those L250 so it’s something to consider even in the long term. All the top Jbl executives had the L250 for a reason.

Cardas make some good value posts and plates btw.

[BMWCCA]

Now if I can get someone to make a house call i'll stock the fridge with their favorite beer (or beverage of their choosing) I may even throw in some cash ;)Somehow I think your time (and money?) might be better spent stocking the fridge, inviting friends over . . . and listening to some music!
:applaud:

[SEAWOLF97]

then (remove) the crossover board

nobody said that op is needed... IF you look at the pics I posted, the posts backsides are easily accessible after removing the LF driver. soldering wire off and back on is super EZ . Get a cheap s.iron and practice on some junk electronics ... it's a lifetime useful skill.

[bradster56]

I certainly understand that upgrading the binding posts might very well NOT result in an audible improvement...I just like to upgrade whenever possible...Audiophile fuses,Upgraded power cords,and lots of other tweeks are part of my reason for living :) Messing with crossover is not for me at this point :eek: I just wanna rock these JBL's!

[Ian Mackenzie]

I understand the joys of submitting to eye candy and the placebo that follows.

Cryo treatment of power reciprocals, fuses ect is pure snake oil imho.

It’s a bit like paying a thousand dollars for chrome plated 2307 horns. But it does not make a scape of difference to what you hear.

It sounds like a conversation to reflect on over at AK.

[SEAWOLF97]

...I just like to upgrade whenever possible...Audiophile fuses,Upgraded power cords,and lots of other tweeks are part of my reason for living :)

Here's a site that can be a new part of your reason for living :)

http://www.shunmook.com/hifiproduct.html

[bradster56]

I can definitely say after 48 years of buying and selling audio equipment that tweeks:

A) Have no effect

B) Have some effect

C) Have a large effect

[Mr. Widget]

I can definitely say after 48 years of buying and selling audio equipment that tweeks:

A) Have no effect

B) Have some effect

C) Have a large effectAgreed, and sometimes B and C are a negative effect.

I can appreciate beautifully made binding posts and beautifully made wristwatches. Typically neither of these offer a performance upgrade to the more pedestrian variants, but they can still be a joy to see and use.


Widget

[bradster56]

Sad but true: the foam behind the dome of the 044ti tweeter has deteriorated which makes them overly bright, lacking detail or ‘harsh’

And you can’t do anything about it because unfortunately, the JBL 044Ti diaphragms are aligned & “glued” at the factory.

Some people had said that they removed the diaphragm but I’ll not try to force it out to replace the damper pad…..

I suggest that you put your tweeter attenuator bus bar on a lower setting.

Cheers,
VSN

[SEAWOLF97]

Your HF's are old enough that I almost guarantee that the foam plug is rotted. A normal problem
with 044's and 044Ti's.


No problems with the tweeters...Nice clean extended highs....


Sad but true: the foam behind the dome of the 044ti tweeter has deteriorated which makes them overly bright, lacking detail or ‘harsh’

And you can’t do anything about it because unfortunately, the JBL 044Ti diaphragms are aligned & “glued” at the factory.

Some people had said that they removed the diaphragm but I’ll not try to force it out to replace the damper pad…..

I suggest that you put your tweeter attenuator bus bar on a lower setting.

Cheers,
VSN



yes or no, in or out, are they perfect or not ? make up your mind.
who is VSN ? He seems "full of it"

"lacking detail" corrected by "put your tweeter attenuator bus bar on a lower setting" :barf:

[bradster56]

https://www.ebay.com/itm/112566419208?ul_noapp=true

[grumpy]

Likely a useful service for those not interested in tinkering with their own.
Seems this service was discussed or noted before.

Removing or attenuating an offending frequency band, is certainly an option
but it would also be reducing performance capability/potential, so it does have the
appearance of a band-aid fix. I’d guess VSN would agree.

[bradster56]

Hey Brad,

I told you that the problem to refurbish the JBL 044Ti damper pad is the diaphragms and they are glued at the factory.

Because numerous of enthusiasts like you, I looked at the 044Ti tweeter situation once more and I am developing a new technique to refurbish the foam!

I’m excited to tell you that very soon I’ll list my JBL 044Ti Tweeter Refurbish Service for 250Ti, 240Ti, 120Ti and 18Ti speakers.

The bad news is the challenging labor, and you can recognize that time is money…..

Look for my new listing in August,
VSN

[DavidF]

The diaphragm assembly is lightly glued onto the magnet plate, yes. Perhaps more of a tacky substance, just enough to hold it in place during assembly. Ordinarily it would not be a big deal to work it off without totally destroying the assembly but complicated by the need to be extremely careful with the voice coil sitting in the narrow gap. I can understand anyone's hesitation with taking this on since there are no fall back replacement parts. I have not tried this but at one time I was considering how fishing line or something more abrasive would work to "floss" the glue joint apart.

Here is a post by someone doing the disassembly. It's in French but you get the gist.

https://www.ls3-5a-forum.com/viewtopic.php?f=21&t=10749

[SEAWOLF97]

Here is a post by someone doing the disassembly. It's in French but you get the gist.

https://www.ls3-5a-forum.com/viewtopic.php?f=21&t=10749

that's funny, they nabbed my original photo from the thread on LHF

(photo du net): ;)

[Ian Mackenzie]

I suggest taking it to an outfit who does driver rebuilding and repairs.

They have access to every conceivable voice coil ect and can assess and the do this job.

The loudspeaker manufacturing industry has a huge parts inventory they can access.

In my area l know of two people with over 30 years of experience who do this kind of work.

If they say it needs whatever done then pay the charge. If they say it can’t be fixed start looking for an alternative.

It might be worth contacting GordonW

[bradster56]

Thanks all for the informative discussion...I'm going to wait until VSN lists his tweeter foam replacement service on Ebay and see costs and time...

[SEAWOLF97]

It might be worth contacting GordonW

+1 ;)

GordonW is a LHF member , who IS a speaker professional.

or Ken.. http://www.uplandloudspeaker.com/
who has a great reputation on this forum too.

[bradster56]

https://www.ebay.com/itm/JBL-044Ti-Tweeter-Refurbish-Service-w-NEW-Damper-Pad-for-250Ti-240Ti-120Ti-18Ti/123265497780