4315 woofer, please help

[snoopy751]

Hello all,
I have bought recently a pair of JBL4315 from eBay, the speakers arrived yesterday, however, one of the woofer 2203A has a problem with no sound.

I took it out and swapped with the another 4315 woofer, which has no problem, meaning the crossover of the speakers are normal.

I used a multi meter to test the impedance of the woofer, and the reading is normal, however, when I use a 9w battery, it has a static sound but the cone does not pop in/out as the another one.

Now my questions :

1. Can this woofer be repaired e.g. by reconing ? As people said it can, but how about it is not the wire of the cone blow up?

2. Is there any replacement of this 2203A (some said 2202H can fit), I do not mind to replace both woofers at the same time, even sound quality is not as good as the original

Thank you

[bldozier]

I read the 2202a/h does not go as low as the
2203, however can accept 2203 cones. If you can find
a voice coil or have a custom wound coil, you should
be allowed to save your original cone, with an updated
coil. The 124a Can be used. The 2204 may need a cone kit
Can you post pictures mate.

http://www.audioheritage.org/vbulletin/showthread.php?8038-JBL-LN3-Project-*Official-Thread&highlight=124a

[Don C]

I have had a couple of speakers that had close to normal resistance, but made no sound. They were LE5-2s. It turned out that the voice coil wire was not fastened to the coil formers, probably because heat had damaged the glue. It's also always possible that the magnets have no magnetism left.

[gibber]

Hello all,
I have bought recently a pair of JBL4315 from eBay, the speakers arrived yesterday, however, one of the woofer 2203A has a problem with no sound.

I took it out and swapped with the another 4315 woofer, which has no problem, meaning the crossover of the speakers are normal.

I used a multi meter to test the impedance of the woofer, and the reading is normal, however, when I use a 9w battery, it has a static sound but the cone does not pop in/out as the another one.

Now my questions :
1. Can this woofer be repaired e.g. by reconing ? As people said it can, but how about it is not the wire of the cone blow up?
2. Is there any replacement of this 2203A (some said 2202H can fit), I do not mind to replace both woofers at the same time, even sound quality is not as good as the original

Thank you

Hi,
is the foam of the other (working) 2203a still OK?
If not, maybe go for a swap to a little bit more modern pair of drivers like Beyma 12B100R. Many other brands are possible, even current production. The more recent, the more "different" the sound might be, though. Sounds strange, but newer materials have a different sound to them. Paper or alu coil formers are rare these days, Nomex might be your best bet. Choose copper wire, not alu, if given the choice.

If a JBL is what should go inside, either eBay hunting for a used 2203a/124a, or a orig. 2203 recone kit, or a pair of 2203H or maybe also a pair of 2204H units might be the way to go.

JBL 2202's will not work, those are short excursion units with stiff suspensions for stage wedge or studio monitor midrange application. 2202's will result in close to zero bass from those 4315 cabs despite their size. 2206's are better than 2202's but still far off from sounding similar

Ralph

[Flodstroem]

I used a multi meter to test the impedance of the woofer, and the reading is normal, however, when I use a 9w battery, it has a static sound but the cone does not pop in/out as the another one. Thank you

Hello snoopy

Try this: check for loose screws on the speaker terminals (inside of the basket). I have found many of those old speakers, especially those with Alnico motors (these are oldest) had loosened screws and unstable measures as a result . They can make sound but no power (dead) If you are lucky then you only had to screw the screws back again Its a little bit tricky because you had to work inside the basket where the cone is but it can be done with short screw-bits. :o:

Check more for more details in this thread:
http://www.audioheritage.org/vbulletin/showthread.php?39303-Speaker-basket-terminals-loose-on-old-JBL

If that isnt the problem then it could be the speakers terminal wires/leads that could have an open circuit (when cone is moving) Try to ohm-measure right on the wires where they are connected to the cone. If broken it could be only some fibers left on those leads and the metal tinsel has ben broken or has ben corroded.

Btw, Welcome to the LHForum snoopy :)

[snoopy751]

Thank you for all the replies, appreciate

Ok thats what has happened, I bought this pair of 4315 from eBay, and got delivered few days ago.

After a listen I realised there was no bass from a speaker, so I took it out and have a test with multi meter, and the impedance reading was normal.

Finally, I brought to a shop in Sydney, called Speaker Hospital, and the guy was well experience and told me that, the 2203A was actually fine, however, might be due to the transportation, the paper cone got stuck and could not pop up, and he reckon the previous owner's reconing and reforming were done poorly, which caused the problem.

Therefore, they will recone both 2203A and replace the surround spider, disassemble and clean. Hope it works.

[gibber]

Thank you for all the replies, appreciate

Ok thats what has happened, I bought this pair of 4315 from eBay, and got delivered few days ago.

After a listen I realised there was no bass from a speaker, so I took it out and have a test with multi meter, and the impedance reading was normal.

Finally, I brought to a shop in Sydney, called Speaker Hospital, and the guy was well experience and told me that, the 2203A was actually fine, however, might be due to the transportation, the paper cone got stuck and could not pop up, and he reckon the previous owner's reconing and reforming were done poorly, which caused the problem.

Therefore, they will recone both 2203A and replace the surround spider, disassemble and clean. Hope it works.


Fine units no longer original unless that shop has the exact kits. Btw, re-reading the thread, i realize *the* likely cause is the pole has shifted sideways due to a strong bump during transport.

Would need de-mag, re-alignment, re-mag in this order and no new kit at all if the old one is salvaged carefully and put in again. Only new foams & dust cap, preferably on both.

[kelossus]

Thank you for all the replies, appreciate

Ok thats what has happened, I bought this pair of 4315 from eBay, and got delivered few days ago.

After a listen I realised there was no bass from a speaker, so I took it out and have a test with multi meter, and the impedance reading was normal.

Finally, I brought to a shop in Sydney, called Speaker Hospital, and the guy was well experience and told me that, the 2203A was actually fine, however, might be due to the transportation, the paper cone got stuck and could not pop up, and he reckon the previous owner's reconing and reforming were done poorly, which caused the problem.

Therefore, they will recone both 2203A and replace the surround spider, disassemble and clean. Hope it works.

Mate, I would be very wary of Speaker Hospital. They couldn't care less about old speakers, they are quite happen to stick the foam on the wrong side of the cone and build you a driver using aftermarket parts paying no attention to the original T/S specs of the driver.

I would be asking for T/S specs once they have rebuilt them.

In my experience there is no one is Sydney capable of rebuilding them properly.

Do you know where the 4315's came from? I have sold two pairs to people in Sydney, curious if they might be a set of mine.

[kelossus]

Btw, I have a set of genuine C8R2203A recones I would consider selling.

I would not let them go for nothing, they are extremely rare and cost me a fortune.

[bldozier]

Can you get some copies made

[snoopy751]

Mate, I would be very wary of Speaker Hospital. They couldn't care less about old speakers, they are quite happen to stick the foam on the wrong side of the cone and build you a driver using aftermarket parts paying no attention to the original T/S specs of the driver.

I would be asking for T/S specs once they have rebuilt them.

In my experience there is no one is Sydney capable of rebuilding them properly.

Do you know where the 4315's came from? I have sold two pairs to people in Sydney, curious if they might be a set of mine.

Understood. No I got it from USA however I am no sure whether the drivers had been reconed, reformed or serviced

[mech986]

Thank you for all the replies, appreciate

Ok thats what has happened, I bought this pair of 4315 from eBay, and got delivered few days ago.

After a listen I realised there was no bass from a speaker, so I took it out and have a test with multi meter, and the impedance reading was normal.

Finally, I brought to a shop in Sydney, called Speaker Hospital, and the guy was well experience and told me that, the 2203A was actually fine, however, might be due to the transportation, the paper cone got stuck and could not pop up, and he reckon the previous owner's reconing and reforming were done poorly, which caused the problem.

Therefore, they will recone both 2203A and replace the surround spider, disassemble and clean. Hope it works.


Fine units no longer original unless that shop has the exact kits. Btw, re-reading the thread, i realize *the* likely cause is the pole has shifted sideways due to a strong bump during transport.

Would need de-mag, re-alignment, re-mag in this order and no new kit at all if the old one is salvaged carefully and put in again. Only new foams & dust cap, preferably on both.
I would agree, the magnet probably shifted which is a much more difficult issue to address, not impossible, but requires skill. If there still is a good ohms reading on the voice coil, then have them VERY VERY carefully separate the surround and spider from the frame and, if possible, lift out the cone/voice coil assembly AND SAVE IT! It is half of the value of the driver. The voice coil should then be inspected for roundness and concentricity, plus the wire should be checked for any signs of burning, scraping, bubbling of insulation, or other damage - that will determine if it can be reused.

Then have the gap inspected and checked with a gap gauge to see if it is free of debris and is even all the way around the pole piece. If it isn't completely symmetrical, then the de-mag, alignment, and remag will need to be done to get the gap correct, of course, getting the magnet free and then regluing / bolting in place as needed.

I would check very carefully about the caveat above of the ability and skill of this shop if there already have been concerns - you want to keep the old parts, and they should not have any damage to them in the process of being removed, it isn't that difficult to preserve the parts. If they can't guarantee it, then you shouldn't be working with them and seek out someone else, even if on another continent.

[mech986]

mate, i would be very wary of speaker hospital. They couldn't care less about old speakers, they are quite happen to stick the foam on the wrong side of the cone and build you a driver using aftermarket parts paying no attention to the original t/s specs of the driver.

I would be asking for t/s specs once they have rebuilt them.

In my experience there is no one is sydney capable of rebuilding them properly.

Do you know where the 4315's came from? I have sold two pairs to people in sydney, curious if they might be a set of mine.

this^^^

[mech986]

By the way, what US state were these shipped from?

[gasfan]

Thank you for all the replies, appreciate

Ok thats what has happened, I bought this pair of 4315 from eBay, and got delivered few days ago.

After a listen I realised there was no bass from a speaker, so I took it out and have a test with multi meter, and the impedance reading was normal.

Finally, I brought to a shop in Sydney, called Speaker Hospital, and the guy was well experience and told me that, the 2203A was actually fine, however, might be due to the transportation, the paper cone got stuck and could not pop up, and he reckon the previous owner's reconing and reforming were done poorly, which caused the problem.

Therefore, they will recone both 2203A and replace the surround spider, disassemble and clean. Hope it works.

Have you checked to see if you can pull the cone forward? If you can, without scraping noises, there's a good chance that the foam dust screen on the pole piece broke up and got sucked into the vc gap and has turned to goo, causing the vc to stick in place. If this is the case, it just needs to be disassembled and cleaned. But don't put a new foam dust cap on. I would stop any reconing procedure by the shop if possible til this has been checked first. Otherwise, they'll likely just rip the original out of the basket and maybe destroy a perfectly good, extremely rare and expensive original cone.

[snoopy751]

Have you checked to see if you can pull the cone forward? If you can, without scraping noises, there's a good chance that the foam dust screen on the pole piece broke up and got sucked into the vc gap and has turned to goo, causing the vc to stick in place. If this is the case, it just needs to be disassembled and cleaned. But don't put a new foam dust cap on. I would stop any reconing procedure by the shop if possible til this has been checked first. Otherwise, they'll likely just rip the original out of the basket and maybe destroy a perfectly good, extremely rare and expensive original cone.

This is really what has been ...

[snoopy751]

The latest update :

I was damn so lucky, and this is what has been done with my 2203As.

I was lucky that I found the shop of Speaker Hospital, in Sydney, they have been in this professional business for longer than 30 years. And the guy who dealt with it has more than 20 years experience. They are really good and know what they are doing.

They told me that the woofer is very precious, and they would not simply to replace any part of the woofer. However, since the reform done previously was badly made, and during the transport the clone got stuck inward.

Therefore they have done carefully and pushed the cone forward, however, the spider was damaged during the transportation and can not be repaired. They suggested me to replace with their old vintage spiders which they have been keeping for long time.

I agreed with it, and they also replaced the foam edges (which were not done properly in the first place)

I took back my woofers, and have a listen for a day. I really can't compare with the previous woofers as one of them had no sound since I received the speakers. I am very happy with sound quality.

And thank you everyone for the inputs on this subject

[snoopy751]

7615176152

[gasfan]

7615176152

Good news!

[Earl K]

The latest update :

I was damn so lucky, and this is what has been done with my 2203As.

I was lucky that I found the shop of Speaker Hospital, in Sydney, they have been in this professional business for longer than 30 years. And the guy who dealt with it has more than 20 years experience. They are really good and know what they are doing.

They told me that the woofer is very precious, and they would not simply to replace any part of the woofer. However, since the reform done previously was badly made, and during the transport the clone got stuck inward.

Therefore they have done carefully and pushed the cone forward, however, the spider was damaged during the transportation and can not be repaired. They suggested me to replace with their old vintage spiders which they have been keeping for long time.

I agreed with it, and they also replaced the foam edges (which were not done properly in the first place)

I took back my woofers, and have a listen for a day. I really can't compare with the previous woofers as one of them had no sound since I received the speakers. I am very happy with sound quality.

And thank you everyone for the inputs on this subject

Well, that is good news.

It would appear that they have "upped-their-game" and now recognize the uniqueness of JBL's proprietary parts recipes.

:)

[snoopy751]

By the way, what US state were these shipped from?


they shipped from California and the seller told me he bought ftom
Japan long time ago

[mech986]

they shipped from California and the seller told me he bought from
Japan long time ago
These shipped from Irvine then? I saw that ad for a few months, they looked in very nice condition. One woofer had a bit of excess glue on the cone and surround, was that the bad one?

http://i.ebayimg.com/images/g/B1YAAOSwaB5Xjbyg/s-l1600.jpghttp://i.ebayimg.com/images/g/E1YAAOSwRgJXjb0s/s-l1600.jpghttp://i.ebayimg.com/images/g/JbAAAOSwj2dXjb02/s-l1600.jpg

[snoopy751]

These shipped from Irvine then? I saw that ad for a few months, they looked in very nice condition. One woofer had a bit of excess glue on the cone and surround, was that the bad one?

http://i.ebayimg.com/images/g/B1YAAOSwaB5Xjbyg/s-l1600.jpghttp://i.ebayimg.com/images/g/E1YAAOSwRgJXjb0s/s-l1600.jpghttp://i.ebayimg.com/images/g/JbAAAOSwj2dXjb02/s-l1600.jpg



Yes, they are from Irvine, and the excess glue one was the one had a problem.

Due to the age of the speakers, I also spotted out that one of the tweeters is slightly quieter than the other

[bldozier]

Mate your equipment definitely exceeds it reputation
take vast care and exercise in your restoration

maybe be easier to track down donors
for kits then begging to understand how come
they are so expensive to maintain.

I remember them

[snoopy751]

Hello again,

I am thinking to have a measure about the OHM reading of the tweeter 2405 of my 4315 speakers, shall i unscrew the back board to take out the tweeter, or unscrew the mid bass them the tweeter from the front ?

[kelossus]

The latest update :

I was damn so lucky, and this is what has been done with my 2203As.

I was lucky that I found the shop of Speaker Hospital, in Sydney, they have been in this professional business for longer than 30 years. And the guy who dealt with it has more than 20 years experience. They are really good and know what they are doing.

They told me that the woofer is very precious, and they would not simply to replace any part of the woofer. However, since the reform done previously was badly made, and during the transport the clone got stuck inward.

Therefore they have done carefully and pushed the cone forward, however, the spider was damaged during the transportation and can not be repaired. They suggested me to replace with their old vintage spiders which they have been keeping for long time.

I agreed with it, and they also replaced the foam edges (which were not done properly in the first place)

I took back my woofers, and have a listen for a day. I really can't compare with the previous woofers as one of them had no sound since I received the speakers. I am very happy with sound quality.

And thank you everyone for the inputs on this subject


I still dont trust them, anyone can recone or repair a speaker. Building a driver to perform to its original T/S specs using OEM parts is beyond their capability. Only a few people in Australia can do it.

Vintage spiders? They are an off the shelf part. A spider with the compliance of "C" is the correct one to use on the 2203's. I would certainly not pay for 30 year old spiders.

I can't tell from your pictures but is the foam stuck on the front of the cone?

[kelossus]

Hello again,

I am thinking to have a measure about the OHM reading of the tweeter 2405 of my 4315 speakers, shall i unscrew the back board to take out the tweeter, or unscrew the mid bass them the tweeter from the front ?

I did not know you could unscrew the backboard on the 4315's. I don't remember that.

The mid-bass is in a sealed dog box so unscrewing that will be of no help. Same as the mid-high.

If you can not unscrew the backboard (which I don't think you can) you have to take the woofer out and reach up inside to get at the tweeter. Its a pain.

[snoopy751]

I did not know you could unscrew the backboard on the 4315's. I don't remember that.

The mid-bass is in a sealed dog box so unscrewing that will be of no help. Same as the mid-high.

If you can not unscrew the backboard (which I don't think you can) you have to take the woofer out and reach up inside to get at the tweeter. Its a pain.

You are right , the mid mass and mid high are sealed.

76233

[mech986]

The screws on the back actually belong to metal braces on the inside of the back panel - they are for securing hardware to "fly" or suspend the speakers (monitors) if needed - all the medium to large monitors are so equipped. So those screws will not provide any better access to the interior. I agree that an access panel in the back like used in 4333 and 434x monitors (primarily for access to heavy horn drivers and tweeters) would have been nice.

You'll need some long arms to reach the tweeter from the woofer. Might be a good idea to put a thick pillow-like pad inside and under the tweeter if you can't reach it so when you unscrew the tweeter, it falls softly (but don't let it bounce). Putting it back in though would be another issue.

I vote to check the midranges first by moving them side to side. Do you know if the previous owner had done any work (changing diaphragms or replacing/reconing midrange) or midbass?

[snoopy751]

The screws on the back actually belong to metal braces on the inside of the back panel - they are for securing hardware to "fly" or suspend the speakers (monitors) if needed - all the medium to large monitors are so equipped. So those screws will not provide any better access to the interior. I agree that an access panel in the back like used in 4333 and 434x monitors (primarily for access to heavy horn drivers and tweeters) would have been nice.

You'll need some long arms to reach the tweeter from the woofer. Might be a good idea to put a thick pillow-like pad inside and under the tweeter if you can't reach it so when you unscrew the tweeter, it falls softly (but don't let it bounce). Putting it back in though would be another issue.

I vote to check the midranges first by moving them side to side. Do you know if the previous owner had done any work (changing diaphragms or replacing/reconing midrange) or midbass?


Thank you all for the inputs, I will check the midranges as suggested.

"Do you know if the previous owner had done any work (changing diaphragms or replacing/reconing midrange) or mid bass" - I did ask and below was what he replied

"I bought them from Japan long time ago and have good time with them, I check all unit they are original and work will"

[snoopy751]

An update

Just managed to take off both tweeter 2405 and have an Ohm test, the readings are 6.5 vs 6.1, and the 6.1 is the one with less brighter.

What shall I do now ? Does it mean I need to replace the Diaphragm D16R2405, one or both ?

Thank you once again

[kelossus]

An update

Just managed to take off both tweeter 2405 and have an Ohm test, the readings are 6.5 vs 6.1, and the 6.1 is the one with less brighter.

What shall I do now ? Does it mean I need to replace the Diaphragm D16R2405, one or both ?

Thank you once again

Mate i don't think a variance of 0.4ohms would be that audible.

I would be more inclined to check the all the pots under the foilcal. They are notorious for failing and I wouldn't be surprised if one of them was the culprit. You are better off with fixed resistors anyway.

[snoopy751]

Mate i don't think a variance of 0.4ohms would be that audible.

I would be more inclined to check the all the pots under the foilcal. They are notorious for failing and I wouldn't be surprised if one of them was the culprit. You are better off with fixed resistors anyway.


Thank you for your response, what do you mean of "Foilcal" ?

[snoopy751]

Thank you for your response, what do you mean of "Foilcal" ?


ok I have rechecked all the connections, seems they are ok

[mech986]

Foilcal is a contraction of foil decal, or the main label on the front baffle with space and markings for the controls. The foilcal is made of a screen plated aluminium foil and that is glued onto the baffle. Unfortunately, it also covers the screws that hold the driver controls board - you would need to get those controls out so they could be sprayed with DeOxit contact cleaner and worked to clean the internal contacts.

The foilcal takes patience, heat from a heat gun or hair dryer, patience, a very flat Implement like a wide scraper or putty blade, patience, and gentle lifting of the foilcal to avoid bends and crease in the foil. This is so you can reuse it in the future, otherwise it costs around $60 per foical to get aftermarket reproductions from the U.S.

if cleaning the controls makes no difference, then the only other option is to have the offending unit inspected and if needed, adjusted (re-center the diaphragm) and see if output improves. This should only be done by someone experienced or authorized by JBL Service to do so. In Addition, even if original, the diaphragms are made of aluminum and can fatigue and crack and eventually fail, then needing replacement with a known good and genuine JBL diaphragm.

[snoopy751]

Foilcal is a contraction of foil decal, or the main label on the front baffle with space and markings for the controls. The foilcal is made of a screen plated aluminium foil and that is glued onto the baffle. Unfortunately, it also covers the screws that hold the driver controls board - you would need to get those controls out so they could be sprayed with DeOxit contact cleaner and worked to clean the internal contacts.

The foilcal takes patience, heat from a heat gun or hair dryer, patience, a very flat Implement like a wide scraper or putty blade, patience, and gentle lifting of the foilcal to avoid bends and crease in the foil. This is so you can reuse it in the future, otherwise it costs around $60 per foical to get aftermarket reproductions from the U.S.

if cleaning the controls makes no difference, then the only other option is to have the offending unit inspected and if needed, adjusted (re-center the diaphragm) and see if output improves. This should only be done by someone experienced or authorized by JBL Service to do so. In Addition, even if original, the diaphragms are made of aluminum and can fatigue and crack and eventually fail, then needing replacement with a known good and genuine JBL diaphragm.

oh I see. Thank you so much

really appreciated for your information

[gasfan]

oh I see. Thank you so much

really appreciated for your information

Could be a problem with the crossover.

[snoopy751]

Could be a problem with the crossover.

Thank you, You are right, I swapped the tweeters with each other, and turn out a issue caused by the crossover

L Channel R Channel Difference
Tweeter with 6.1 OHM Tweeter with 6.5 OHM R is much brighter than L (obvious)

Tweeter with 6.5 OHM Tweeter with 6.1 OHM R is a bit brighter than L

So, what can I do now ?

[gasfan]

Thank you, You are right, I swapped the tweeters with each other, and turn out a issue caused by the crossover

L Channel R Channel Difference
Tweeter with 6.1 OHM Tweeter with 6.5 OHM R is much brighter than L (obvious)

Tweeter with 6.5 OHM Tweeter with 6.1 OHM R is a bit brighter than L

So, what can I do now ?

Looks like there's a couple of 1.5uf electrolytic caps on the HF part of the crossover. I would replace them in both crossovers. It's probably a good idea to replace all the electrolytics. I don't believe that difference in DCR of the 2405s is anywhere near audible btw. You can have that much variation just by the way the probe of your dvm touches the speaker contact.

[snoopy751]

Thank you,

To be honest, I feel a bit tired to deal with this pair of 4315, as it caused few issues, from delayed shipment, 2203A / 2405 issues, also just received a new order of a pair of JBL plates, I was ordered for "4315" and they turn out to be "4350"

Listen to music really can't take in too serious, I think I may left these issues as they are ... rather spending more time on listening music

[snoopy751]

76324
Thank you,

To be honest, I feel a bit tired to deal with this pair of 4315, as it caused few issues, from delayed shipment, 2203A / 2405 issues, also just received a new order of a pair of JBL plates, I was ordered for "4315" and they turn out to be "4350"

Listen to music really can't take in too serious, I think I may left these issues as they are ... rather spending more time on listening music

[gasfan]

76324 Cosmetic issues are less important. But if they don't function as they should, it's like a constant drip or pebble in your shoe. Just leave it for a while til you get the inclination.:)

[snoopy751]

Cosmetic issues are less important. But if they don't function as they should, it's like a constant drip or pebble in your shoe. Just leave it for a while til you get the inclination.:)


well said .. thank you

let see ...

[MikeM]

Hello all,
I have bought recently a pair of JBL4315 from eBay, the speakers arrived yesterday, however, one of the woofer 2203A has a problem with no sound.

I took it out and swapped with the another 4315 woofer, which has no problem, meaning the crossover of the speakers are normal.

I used a multi meter to test the impedance of the woofer, and the reading is normal, however, when I use a 9w battery, it has a static sound but the cone does not pop in/out as the another one.

Now my questions :

1. Can this woofer be repaired e.g. by reconing ? As people said it can, but how about it is not the wire of the cone blow up?

2. Is there any replacement of this 2203A (some said 2202H can fit), I do not mind to replace both woofers at the same time, even sound quality is not as good as the original

Thank you

Nice looking pair. Enjoy

[snoopy751]

Nice looking pair. Enjoy


Thank you so much

[snoopy751]

I am thinking to buy an extra pair of 2405 tweeter, do you think i can pair this extra pair to "JBL N1200 16-ohm Crossover Network" ?

If yes, then the connection will be

cable from amp to 4315 > cable from 4315 to this N1200 > cable to 2405

Thank you once more

[mech986]

I am thinking to buy an extra pair of 2405 tweeter, do you think i can pair this extra pair to "JBL N1200 16-ohm Crossover Network" ?

If yes, then the connection will be

cable from amp to 4315 > cable from 4315 to this N1200 > cable to 2405

Thank you once more

No, 2405 cannot work with the N1200. The 2405 crosses over at 8000hz with the 4315 crossover network. The N1200 crosses at a much lower 1200hz and is meant to be used with the 175DLH compression driver which has a larger diaphragm and designed to play down towards that lower area. The N1200 would allow too much lower and upper midrange energy to get to the diaphragm which would lead to damaging the 2405 diaphragm.

If you want to experiment, sure getting an extra pair of 2405's with the correct and original JBL OEM diaphragms could be a reasonably cost effective way to obtain two JBL diaphragms. You could then swap in the spare pair and see if the problem still resides with the crossover, or you could see if one pair of the 4 four drivers complementary matches the issue with the crossover to even out the high frequencies. The 2405 has plenty of additional output available if the L-pads are working properly so you should be able to get all the HF sizzle / output you want. Otherwise, it would be a good idea to clean the L-pads with DeOxit or similar contact / potentiometer cleaner and exercise the controls about 40 times each. If that doesn't clean the uneven output issue, then one should look into replacing the capacitors and resistors with new. We can discuss parts options if it comes to that.

[snoopy751]

No, 2405 cannot work with the N1200. The 2405 crosses over at 8000hz with the 4315 crossover network. The N1200 crosses at a much lower 1200hz and is meant to be used with the 175DLH compression driver which has a larger diaphragm and designed to play down towards that lower area. The N1200 would allow too much lower and upper midrange energy to get to the diaphragm which would lead to damaging the 2405 diaphragm.

If you want to experiment, sure getting an extra pair of 2405's with the correct and original JBL OEM diaphragms could be a reasonably cost effective way to obtain two JBL diaphragms. You could then swap in the spare pair and see if the problem still resides with the crossover, or you could see if one pair of the 4 four drivers complementary matches the issue with the crossover to even out the high frequencies. The 2405 has plenty of additional output available if the L-pads are working properly so you should be able to get all the HF sizzle / output you want. Otherwise, it would be a good idea to clean the L-pads with DeOxit or similar contact / potentiometer cleaner and exercise the controls about 40 times each. If that doesn't clean the uneven output issue, then one should look into replacing the capacitors and resistors with new. We can discuss parts options if it comes to that.

Thank you for the explanation.

I did swap over two 2405s, and seems both tweeters are fine (even the one with lower OHM reading), therefore, I believe one of the crossover is causing the issue. Likely that a replacing the capacitors and resistors with new are needed

[snoopy751]

Updated

This morning received a pair of refurnished NOS 2405 tweeters (the serial nos. are very very closed) , then replaced the old pair (the serial nos. different is around 1xxx).

Have a listen for more than two hours, the unbalance of tweeters is now finally gone.

Very happy that now I can have a normal pair of 4315 ... sound is excellent ...

Thank you once again everyone, for your helps.

[JeffW]

Just a heads-up, and you may not need them any more, but a fellow Aussie has a pair of 2203 cone kits for sale:

http://www.audioheritage.org/vbulletin/showthread.php?39558-For-Sale-JBL-C8R2203-C8R112A-2108-C8R121A-Recone-Kits

[snoopy751]

Just a heads-up, and you may not need them any more, but a fellow Aussie has a pair of 2203 cone kits for sale:

http://www.audioheritage.org/vbulletin/showthread.php?39558-For-Sale-JBL-C8R2203-C8R112A-2108-C8R121A-Recone-Kits


Thank you for the heads-up, I think I pass this time ... may be few years later, I may upgrade my 4315 with a bigger model ...