2405H restore help

[GrooveControl]

I purchased a pair of 2405H that arrived in bad shape. So I sanded them down and repainted, now they look great!

Then I ordered and installed replacement diaphragms. Here comes the problem... the two tweets, both with new diaphragms do not sound the same.

I want to try to reseat/fuss with one of them but I don't know which one is off. Here are response curves of the two. I can't find response curves for this tweeter on the web so I don't know which one is closer to spec. Can anyone tell me which response appears to be more in line with what these tweeter should be?

Note: Measurement system not calibrated, and lots of noise in the room, but you get the idea.

Thanks

55957

[Mike F]

Hello and welcome! What kind of diaphragms did you install?

[GrooveControl]

Aftermarket, about $30ea. Thought I would try them, given the cost of the jbl parts.

Actually, the blue line sounds good. Sounds like a crossover is installed when it isn't.

[Mike F]

Aftermarket, about $30ea. Thought I would try them, given the cost of the jbl parts.

Actually, the blue line sounds good. Sounds like a crossover is installed when it isn't.

Unfortunately, you get what you pay for. I`ve had the misfortune of going that route on a couple of occasions, never again. The only good thing about them is that they "work";)
There is much info on these forums with regards to replacement diaphragms (Chinese) and the general consensus is that they are all crap.

[GrooveControl]

the general consensus is that they are all crap.

I'm going to try the high shelf on the 2445/2380 before dropping $150+ each for the JBL diaphrgms.

[Mike F]

I'm going to try the high shelf on the 2445/2380 before dropping $150+ each for the JBL diaphrgms.

Sure worth a shot. It may not give you the sparkle a proper 2405 would but at the very least, the frequency response will be more consistent (assuming the 2445s are loaded with real `frams:))

[JeffW]

For $30, you might just buy a couple more and see if you can get a pair to match up fairly close. The new production JBL units seem to be stuggling with QC.

[Mike F]

For $30, you might just buy a couple more and see if you can get a pair to match up fairly close. The new production JBL units seem to be stuggling with QC.

True that. Member Sekkes (sp?) recently had some issues with the now, made in Mexico JBL units.
Groove, if your interested in trying Jeffs suggestion, I have a couple of `frams I can lay on you
"pas chere" as we say here in La Belle Province;)

[GrooveControl]

Thanks folks, I want to try removing/cleaning installing again.

Mike F, thanks for the offer, I'll get back to you on that.

Does anyone know which curve more closely resembles the original response curve of the 2405? I can't seem to find it.

[maxwedge]

Looking over this thread may help you.
http://www.audioheritage.org/vbulletin/showthread.php?6368-Ring-Radiator-Comparisons

[GrooveControl]

Thanks Scottie! The blue trace looks much closer to the 2405 graphs. It sounds much better too. I'll have to follow up with the vendor to see what this is all about. I would not have imagined that two new frams could sound & measure so differently.

Dan

[cooky1257]

Expense aside, response is one thing, character of sound/sound quality is another.
A purist wouldn't call them 2405's because they no longer are.
A bit like dropping a Focus engine into a Porche and still calling it a Porche.
I am aware though that the originals can be rather pricey.........

[ivica]

I purchased a pair of 2405H that arrived in bad shape. So I sanded them down and repainted, now they look great!

Then I ordered and installed replacement diaphragms. Here comes the problem... the two tweets, both with new diaphragms do not sound the same.

I want to try to reseat/fuss with one of them but I don't know which one is off. Here are response curves of the two. I can't find response curves for this tweeter on the web so I don't know which one is closer to spec. Can anyone tell me which response appears to be more in line with what these tweeter should be?

Note: Measurement system not calibrated, and lots of noise in the room, but you get the idea.

Thanks

55957

My experience with JBL2405 is: only original diaphragm D16R2405 would give You acceptable response, but for the (almost) same amount you can get the Beyma CP21-F driver ( http://www.usspeaker.com/beyma%20CP21F-1.htm ), but its 'character of the sound', is for me, 'a little bit intrusive' compared to a good JBL2405. I have no experience with BMS 4540 either, but with appropriated HF horn seems to be interesting solution too.

Trying with AF diaphragms , is wasting money , for my experience.
Regards
Ivica

[JeffW]

Expense aside, response is one thing, character of sound/sound quality is another.
A purist wouldn't call them 2405's because they no longer are.
A bit like dropping a Focus engine into a Porche and still calling it a Porche.
I am aware though that the originals can be rather pricey.........

Expense aside, the new production JBL 'phragms appear to be unusable. So you can stick a blown Porche engine in your Porche and keep it in the garage, or stick a Focus engine in it and drive it.

[Mr. Widget]

Expense aside, the new production JBL 'phragms appear to be unusable. So you can stick a blown Porche engine in your Porche and keep it in the garage, or stick a Focus engine in it and drive it.Personally, I'd have a factory authorized repair shop that I trusted do the work. If there are production issues they are fully covered under the warranty when going this route and JBL will send replacements at no cost.


Widget

[JeffW]

Personally, I'd have a factory authorized repair shop that I trusted do the work. If there are production issues they are fully covered under the warranty when going this route and JBL will send replacements at no cost.


Widget


Maybe the factory authorized shops have access to better components than JBL sells to consumers. If not, you could be without tweeters for a very long time while the shop waits on usable parts.

[Mr. Widget]

If not, you could be without tweeters for a very long time while the shop waits on usable parts.Perhaps, but what's the alternative? If you screw around with them yourself you could be out an equally long time and possibly out a lot more cash.


Widget

[cooky1257]

Expense aside, the new production JBL 'phragms appear to be unusable. So you can stick a blown Porche engine in your Porche and keep it in the garage, or stick a Focus engine in it and drive it.

True but it wont drive like a Porche, I've always understood 'restore' to mean bring back to original condition.

[mech986]

Expense aside, response is one thing, character of sound/sound quality is another.
A purist wouldn't call them 2405's because they no longer are.
A bit like dropping a Focus engine into a Porche and still calling it a Porche.
I am aware though that the originals can be rather pricey.........


True but it wont drive like a Porche, I've always understood 'restore' to mean bring back to original condition.


Expense aside, the new production JBL 'phragms appear to be unusable. So you can stick a blown Porche engine in your Porche and keep it in the garage, or stick a Focus engine in it and drive it.

If you're going to use the analogy, please spell it right. Sit on your porch(e), own and drive a Porsche (two syllable please). :D


Personally, I'd have a factory authorized repair shop that I trusted do the work. If there are production issues they are fully covered under the warranty when going this route and JBL will send replacements at no cost.

Widget

This really is the best way to go from a time and expense standpoint. The Factory service shop can, at your request at time of installation, run a frequency response test and listening test, and they'll pretty much know whether the diaphragm is good. If it isn't, and most of them will know right away if they have any experience with the 2405, then they can contact JBL for another diaphragm without you having to lose the time of picking it up and then returning it again. Plus if the unit fails under warranty, then you still have the backing of JBL for the warranty.

I know the issue of cost is sometimes difficult, but when you are paying for JBL engineering and production, you usually get the right results. So far, no aftermarket 2405/2402 diaphragm has even come close, mostly because the aftermarket producers are only interested in profit, not performance, and its not their name or reputation on the line with these parts (you can't even figure out who the real supplier is, at least that could give us some way of choosing a better aftermarket supplier). IF it was so easy to make such a small thing, you'd think they would have figured it out by now. There MAY be someone eventually who could consistently build a comparably good diaphragm to JBL, but I bet it won't be inexpensive either.

My 0.02.

Bart

[Mike F]

If you're going to use the analogy, please spell it right. Sit on your porch(e), own and drive a Porsche (two syllable please). :D



This really is the best way to go from a time and expense standpoint. The Factory service shop can, at your request at time of installation, run a frequency response test and listening test, and they'll pretty much know whether the diaphragm is good. If it isn't, and most of them will know right away if they have any experience with the 2405, then they can contact JBL for another diaphragm without you having to lose the time of picking it up and then returning it again. Plus if the unit fails under warranty, then you still have the backing of JBL for the warranty.

I know the issue of cost is sometimes difficult, but when you are paying for JBL engineering and production, you usually get the right results. So far, no aftermarket 2405/2402 diaphragm has even come close, mostly because the aftermarket producers are only interested in profit, not performance, and its not their name or reputation on the line with these parts (you can't even figure out who the real supplier is, at least that could give us some way of choosing a better aftermarket supplier). IF it was so easy to make such a small thing, you'd think they would have figured it out by now. There MAY be someone eventually who could consistently build a comparably good diaphragm to JBL, but I bet it won't be inexpensive either.

My 0.02.

Bart

Radian, are you listening?:D

[cooky1257]

If you're going to use the analogy, please spell it right. Sit on your porch(e), own and drive a Porsche (two syllable please). :D




Bart

I blame the germans.:D

[hjames]

I blame the germans.:D

Do they have a porch(e)?

[mech986]

Radian, are you listening?:D

maybe for the other compression drivers, but they don't make anything for ring radiators like the 2405/077 or 2402/075.

[4313B]

Porsche (two syllable please). :DThe two syllable Henschel is better. :D

[JeffW]

Perhaps, but what's the alternative? If you screw around with them yourself you could be out an equally long time and possibly out a lot more cash.


Widget

I think the best alternative would be to have a ready supply of usable factory diaphragms, but then I'm a hopeless romantic.

[Mike F]

maybe for the other compression drivers, but they don't make anything for ring radiators like the 2405/077 or 2402/075.

Hence my post. With the shear number of ring radiators on the planet, I dont see why they dont or wont produce an alternative to what is currently available.