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Loren42
06-03-2009, 06:43 AM
I received two 2235Hs yesterday and it looks like I will be the one taking it on the chin.

http://www.mdbq.net/2235Damage/2235_0.jpg

The other has pin holes in the cone:

http://www.mdbq.net/2235Damage/2235_4.jpg

What are my repair options?

I could outright recone both, which is the most expensive method, but also the most likely to produce the correct sound.

I could replace the dome on the one and seal the pinholes on the other. That is the cheapest road and I can't imagine it would impact sonic performance. The drivers will be devalued in that condition.

Thoughts and recommendations?

Where is a good recone shop and any guestimate on cost?

Where can I get a new dust cap and maybe new foam surrounds? Ebay has generic ones from $30 and up, but I have no idea if they are any good.

Help appreciated!

Thanks!!!

BMWCCA
06-03-2009, 06:53 AM
I don't recall what the intended use for these was, but if you can play them now to determine if they still function, it might be a good idea. Repairing the small holes may require no more than small pieces of paper and some Elmer's. I've had good luck on dented paper dust domes doing the following.

Turn on your vacuum cleaner. Take your vacuum cleaner hose without attachment and (steadying it with both hands) carefully, slowly, lower it near the dome. Go all the way to the dome if you have to. If the dome sucks right out with a small pop then carefully break the suction by pulling away or tilting the hose. If the dome resists, cover the surrounding cone area and lightly spritz the dust dome with a water mister. Let it sit just a bit to soak in and try the suction hose again. The result may not yield a perfect dome, but it just might. Regardless, as they say on Ebay, it won't affect the sound! ;)

I had a shock when I tried this on some free Sansui speakers the other day. The dome popped out immediately, and it was rubber!

Good luck. Let us know if they sound okay before you spend a ton on repairing them.

Loren42
06-03-2009, 07:43 AM
I don't recall what the intended use for these was, but if you can play them now to determine if they still function, it might be a good idea. Repairing the small holes may require no more than small pieces of paper and some Elmer's. I've had good luck on dented paper dust domes doing the following.

Turn on your vacuum cleaner. Take your vacuum cleaner hose without attachment and (steadying it with both hands) carefully, slowly, lower it near the dome. Go all the way to the dome if you have to. If the dome sucks right out with a small pop then carefully break the suction by pulling away or tilting the hose. If the dome resists, cover the surrounding cone area and lightly spritz the dust dome with a water mister. Let it sit just a bit to soak in and try the suction hose again. The result may not yield a perfect dome, but it just might. Regardless, as they say on Ebay, it won't affect the sound! ;)

I had a shock when I tried this on some free Sansui speakers the other day. The dome popped out immediately, and it was rubber!

Good luck. Let us know if they sound okay before you spend a ton on repairing them.

Great idea for the dust cap!

When I first opened them the foam on one of the speakers has a very slight ripple in it. That has since disappeared, so I guess the cone was stressed. The baskets, when measured with a dial caliper, are still round 0.004", which should be fine. I have yet to test them electrically, but no audible noise is heard or rubbing felt when the cone is moved.

Do you know what level the cone's edge should be relative to the far edge of the foam surround? Both appear slightly sunken compared to the edge where the frame and outer foam surround meet. I assume this is normal since both are exactly the same.

Duco cement is something I have used a number of times to repair speaker cones.

These are intended as new woofers for my 3-way HiFi cabinets (http://web.me.com/mdebeque/Site/Pyramid_Speakers.html). I no longer use a passive crossover, but have gone totally active.

I'll pop out the dome, seal the pin holes, and drop them into a cabinet for a test ride in a few days. Not much effort (or cost) involved in doing that.

Wish I had one of those T/S speaker testers, but not able to drop $100 - $150 to buy that just yet. Be nice to measure the exact T/S constants, although...

Mr. Widget
06-03-2009, 07:52 AM
Wish I had one of those T/S speaker testers, but not able to drop $100 - $150 to buy that just yet. Be nice to measure the exact T/S constants, although...Maybe someone in your area could lend you some test gear?

I agree with BMW... suck out the dome, it will look better, but not perfect. For the small tears, I'd use tissue paper and white glue. Give it a shot... as long as the VCs don't rub, you should be good to go until you can afford a proper recone... really too bad, those cones look fairly new. :(


Widget

BMWCCA
06-03-2009, 08:03 AM
Duco cement is something I have used a number of times to repair speaker cones.Duco is a very versatile product but years of making architectural models in school taught me nothing works better on pulp products than Elmer's. Aleen's Tacky Glue is similar and often used for applying new surrounds. For your purpose, Elmer's is easier to work with, less viscous, and can be thinned to work decoupage-style, which is pretty much what you'll be doing. It can also be removed by soaking later, if necessary.

What's my experience? Years ago repairing a small tear in a D130, shipped by UPS in a C37 cabinet, that still broke loose from the factory mounting bolts and arrived swinging from one bolt in the broken cabinet. The good news was that UPS paid the eBay seller who refunded my money in full. He even suggested I remove the D130 and keep it for all my trouble. UPS never noticed the substantial weight difference. The cabinet ended up in a dumpster somewhere in Ohio. :(

grumpy
06-03-2009, 08:05 AM
I'll just add to what's been said... it appears that when the holes were made, they left
much of the material, which could be manipulated back into the hole area, minimizing
the appearance from the front (putting any tissue, etc... on the rear of the cone).

Also, if the 2235 with the pushed in dome is headed for sub duty, sucking it out is
probably OK, but I'd personally want the dome replaced (not crazy expensive, but
quality on the glue-line matters) especially if attempting to use it into the KHz range
(ala 4430).

-grumpy

tomee
06-03-2009, 08:19 AM
If you're going to refoam these you might think about cutting the dust cap off and replacing it with a new one, or repairing it when it's off. Then you can use shims during the refoam. You can buy the replacement dustcaps from JBL pro - I wouldn't use a generic dustcap as the paper isn't the same (too thin).

Mr. Widget
06-03-2009, 08:29 AM
I'll just add to what's been said... it appears that when the holes were made, they left
much of the material, which could be manipulated back into the hole area, minimizing
the appearance from the front (putting any tissue, etc... on the rear of the cone).Exactly what I was thinking.


... but I'd personally want the dome replaced (not crazy expensive, but
quality on the glue-line matters) especially if attempting to use it into the KHz range
(ala 4430). You think you could actually hear the difference? Not questioning you, just asking the question. I've never used a JBL with smashed dome... but I can't imagine a paper dustcap contributes much to the sound, but then again, it is fastened directly to the VC.

Either way, as you say... dust caps are cheap. I'd find and pay a real pro to install it though... even most pros do a pretty bad job cosmetically with the glue line. :banghead:


Widget

Loren42
06-03-2009, 08:50 AM
Crossover is at about 400 Hz, so they are not subject to too high a frequency.

Electrical check shows 6.4 Ω and 6.6Ω each.

What disturbs me now is both speakers' cones are slightly depressed in the basket. That is, the edge where the foam and the surround meet is slightly lower than the edge where the surround and metal basket meet.

Does anyone know if this is normal?

http://www.mdbq.net/cutaway.jpg

grumpy
06-03-2009, 09:36 AM
... can look tonight if no one else responds first. Does the spider also look sunk in?

Re dome... I've not measured or heard a difference with a crushed dome, but then I've
also never set up a test to do so... so my primary reason is based on conjecture:
that in other drivers, the dome and material claim to be optimized for HF extension
or FR smoothness, etc ... (at least partly due to the proximity of the voice-coil joint, as
you mention) so I'm -expecting- there to be a measurable effect. Secondary reason is
that it would bother me visually. Thirdly, it's not a particularly expensive procedure.

Loren42
06-03-2009, 09:56 AM
... can look tonight if no one else responds first. Does the spider also look sunk in?


Yes, both look equally sunk inward, but that is kind of a subjective answer. The measurement I made is probably a little more quantitative at the surround.

Neither cone looks skewed or off center, they are symetrical. They were face to face, but the basket edge of one contacted the dome of the other and the other's tie wrap punctured the first's cone in about 6 places as shown earlier in my pictures.

There were loose foam peanuts filling the box, but they were pretty evenly distributed inside.

grumpy
06-03-2009, 11:07 AM
subjective answer...Best I can do without a unit to measure in front of me :). Generally the spider should
not be sunk in, but be flat (other than the accordion shape) from where it attaches
to the frame, to where it is glued to the voice coil/former. I've had units shipped to
me that started out a bit sunken (from improper packing) and worked their way back to
normalcy after running the driver with significant bass-range exercise... but it -could- also
be that the seller had 2235H's that -needed- re-coning but just had the foam done.

At any rate, I'll measure the frame/cone-lip offset of a professionally re-coned 2234/5
in ~6-7 hours.

Loren42
06-03-2009, 12:19 PM
Best I can do without a unit to measure in front of me :). Generally the spider should
not be sunk in, but be flat (other than the accordion shape) from where it attaches
to the frame, to where it is glued to the voice coil/former. I've had units shipped to
me that started out a bit sunken (from improper packing) and worked their way back to
normalcy after running the driver with significant bass-range exercise... but it -could- also
be that the seller had 2235H's that -needed- re-coning but just had the foam done.

At any rate, I'll measure the frame/cone-lip offset of a professionally re-coned 2234/5
in ~6-7 hours.

Thanks!

Loren42
06-03-2009, 01:42 PM
The spiders appear to be sunk in the same amount that the cone at its outer edge is sunk in.

It's not easy to see with this photo, but this is the best I can do with available lighting.

http://www.mdbq.net/2235Damage/spider.jpg

Both speakers are exactly the same with this respect. I notice that the glue line for the spider is a bit sloppy, but no idea if these are original or reconed. A theory is that they were reconed and the spiders were in this condition when the job was done?

Still, I have no idea if this is the normal or not, but my guess is that it is not! Another clue is that the amount of physical movement in the positive and negative direction when pulled and pushed by hand seems to be asymmetric. The extension forward looks greater than downward. I will try to put them on the bench and apply a DC signal and then reverse the DC polarity and physically measure the cone excursion in and out.

If this is abnormal, the question is, what caused both spiders to sink almost 3/16"? Shipping? I kind of think not because both appear the same. Could these have been stored a long, long time facing up and gravity caused the cones to drop?

I would be interested in peoples' opinions or if someone has a working 2235 that they can visually compare what they have to what I am observing.

Loren

grumpy
06-03-2009, 02:06 PM
Could these have been stored a long, long time facing up?

yyyep. Before or after a re-foam (if that was done).

BMWCCA
06-03-2009, 02:08 PM
I don't see how you could strap those big boys together face-to-face and not compress the surround, cone, and spider since it appears the surround stands proud of the frame. Hopefully with some good exercise they'll return to their original position as Grumpy mentioned.

Earl K
06-03-2009, 02:12 PM
I would be interested in peoples' opinions or if someone has a working 2235 that they can visually compare what they have to what I am observing.

- Your spiders ( & cones ) have sunk / try storing them upside down for some time & see if they come back to level.

- Most of us long time posters realize that it's a no-no to ship large woofers like this, "face to face" . This , meaning heavy cones having foam surrounds that stick above the basket edge .


- ( Smaller sizes can get away with this methodology / though I once had 2 le10Hs trash each other early in my eBay purchasing days. )


- Part of the reason your spiders are pushed in, is due to the contribution of the two cones working against each other when in shipment .
- Another reason can be that the woofer spiders were already "bagged" because of heavy use ( refoams only mask this problem ) .

- IMO, the woofers needed a spacer added between them ( so the surrounds didn't touch each other ) as well as a piece of cardboard in the middle .
- Better yet, they should be in separate boxes with a surround hole in place for each box ( this is how JBL ships their pro product ) .

- Live & Learn I guess .

>< cheers :)

SMKSoundPro
06-03-2009, 03:06 PM
Question:
Has anyone considered that if the dome is pushed in, that the mass loading ring underneath could be broken loose? Crying out to be a 2234?

Cut out the dome, inspect the mass loading ring, shim and and refoam, new JBL dome.

Recone when possible to assure proper specs, before 2235 kits are NLA.

scotty.

Loren42
06-03-2009, 04:00 PM
Question:
Has anyone considered that if the dome is pushed in, that the mass loading ring underneath could be broken loose? Crying out to be a 2234?

Cut out the dome, inspect the mass loading ring, shim and and refoam, new JBL dome.

Recone when possible to assure proper specs, before 2235 kits are NLA.

scotty.

2235H has a mass loading ring? I thought that was only the 2231 that had those.

subwoof
06-03-2009, 04:13 PM
get some toilet paper rolls and put 2 180 degrees apart between the cone and frame to push the cone assembly out.

Leave in for a few days.

Remove and see what the cone does after 1 hour.

THEN make sure to store the cones face down with a spacer on the gasket.

The spider on the 2234/5 is thinner than the others and the mass ring on the '35 might cause an older kit to sink in a bit.

If there is enough of the original paper on the pin holes, use a toothpick and elmers to repair. NO tissue!

sub

grumpy
06-03-2009, 06:35 PM
I could measure no appreciable offset between cone rim and frame
(where surround mounts); measurement was probably only accurate to within
1/16" or so ... didn't want to poke the cone with a pair of dividers :)

... should mention that the speaker was vertical (on a baffle) when
checking this.

Loren42
06-03-2009, 07:25 PM
I could measure no appreciable offset between cone rim and frame
(where surround mounts); measurement was probably only accurate to within
1/16" or so ... didn't want to poke the cone with a pair of dividers :)

... should mention that the speaker was vertical (on a baffle) when
checking this.

Thanks. Looks like I need to either recone them or at least try extending the cone for some period of time to get them back to where they belong.

Allanvh5150
06-03-2009, 08:09 PM
Just try running them for a while in the normal position. I have put new kits in that sit low for a while. After a bit of settling in and they seem to come right. You have nothing to loose of you are thinking of doing a recone anyway.

Allan.

Loren42
06-04-2009, 03:26 AM
Just try running them for a while in the normal position. I have put new kits in that sit low for a while. After a bit of settling in and they seem to come right. You have nothing to loose of you are thinking of doing a recone anyway.

Allan.

I am running 1.8 VDC into the speaker at .28 Amps (0.6 Watts) to push the cone the opposite direction. After about 6 hours the suspension looks better, but I think it needs more time.

JBLRaiser
06-04-2009, 04:46 AM
here is a list of JBL service centers in Fla.
http://www.jblproservice.com/service/florida.html

Loren42
06-04-2009, 06:30 AM
here is a list of JBL service centers in Fla.
http://www.jblproservice.com/service/florida.html

Thanks! Orlando is the closest.

I popped the dome out, but I had to use a shop vac! House vac would not do it. Looks ratty, but it gets it away from the VC where it belongs.

BMWCCA
06-04-2009, 06:37 AM
Looks ratty, but it gets it away from the VC where it belongs.Did you wet it first?

Loren42
06-04-2009, 07:33 AM
Did you wet it first?

No. I was just about to go that route, but the shop vac pulled it out without too much violence.

The Orlando speaker recone shop quoted about $30 to replace the dome and about $250 each for an OEM recone.

I am still feeding about 2 Watts DC into each speaker to see if I can get the cones to recenter, but if this does work, it will probably takes days or weeks!

Right now I have little to lose by trying.

I was thinking of sweeping them with a tone to see if I can find their Fs. That might tell me how well they might perform to their original specs. If the Fs is all messed up, then they probably are trashed.

John
06-04-2009, 02:51 PM
Did you talk to the seller?

What was his reply?

Once you start messing with these all parties will point to you.:(

BMWCCA
06-04-2009, 03:28 PM
No. I was just about to go that route, but the shop vac pulled it out without too much violence.
I asked because wetting the dust cap allows the creases to relax and the suction can more easily fill out the dome shape. Nothing keeping you from wetting them now and applying more suction. I have a 128H-1 that looked just like your dustcap and came out so clean I can't even tell which one got smooshed. ;)

Loren42
06-04-2009, 03:37 PM
Did you talk to the seller?

What was his reply?

Once you start messing with these all parties will point to you.:(

No reply from the owner. I suspect that I will never get a reply.

Loren42
06-08-2009, 12:35 PM
Never a response from the seller.

My girlfriend finally said, "Let's hear them!"

So, I popped out the Dayton DC380-8 and in went the 2235Hs.

Bottom line, as butt ugly as these drivers look (even after the minor repairs), they seem to play great.

Sound quality is better with richer bass and better low end definition. Although it is hard substantiate, the upper bass/lower midrange should be an improvement, too.

The Dayton had a nasty cone breakup at the lower crossover point of 400 Hz, where as the 2235H response is much more linear.

One day I may recone them, but no funds to do that now, so I will just let them make music the way they are right now. The sonic difference between what I have now and a fresh recone probably would not be noticeable.

BMWCCA
06-08-2009, 12:51 PM
Bottom line, as butt ugly as these drivers look (even after the minor repairs), they seem to play great.

:applaud:Physical beauty is highly overrated . . . except perhaps in girlfriends. ;)

Allanvh5150
06-08-2009, 12:52 PM
The sonic difference between what I have now and a fresh recone probably would not be noticeable.

True.:)

Allan.

Russellc
06-09-2009, 12:09 PM
Never a response from the seller.

My girlfriend finally said, "Let's hear them!"

So, I popped out the Dayton DC380-8 and in went the 2235Hs.

Bottom line, as butt ugly as these drivers look (even after the minor repairs), they seem to play great.

Sound quality is better with richer bass and better low end definition. Although it is hard substantiate, the upper bass/lower midrange should be an improvement, too.

The Dayton had a nasty cone breakup at the lower crossover point of 400 Hz, where as the 2235H response is much more linear.

One day I may recone them, but no funds to do that now, so I will just let them make music the way they are right now. The sonic difference between what I have now and a fresh recone probably would not be noticeable.
As someone said earlier, do it before they become NLA from JBL. I paid a little over 400 for a pair to be redone recently at the JBL service center located here in KC.

Russellc

Allanvh5150
06-09-2009, 12:53 PM
As someone said earlier, do it before they become NLA from JBL. I paid a little over 400 for a pair to be redone recently at the JBL service center located here in KC.

Russellc

I think it will be a long time before JBL stop making parts for the popular drivers. I would hate to think how many 2225/2235's there are around the planet.

Allan.

Loren42
06-09-2009, 03:59 PM
Worse come to worse there are always the generic recone kits.

BMWCCA
06-09-2009, 05:59 PM
. . . generic recone kits.:crying: Blasphemy! :eek:

Loren42
06-09-2009, 07:10 PM
:crying: Blasphemy! :eek:

Only you hairdresser will know. :banana:

Robh3606
06-09-2009, 08:44 PM
Worse come to worse there are always the generic recone kits.


Do you get a mass ring with those??

Rob:)

Loren42
06-10-2009, 04:14 AM
Do you get a mass ring with those??

Rob:)

No!

You have to salvage the old one, whatever that involves.

Earl K
06-10-2009, 04:28 AM
I received two 2235Hs yesterday and it looks like I will be the one taking it on the chin.

Did you talk to the seller?

No reply from the owner.

I suspect that I will never get a reply.



Worse come to worse there are always the generic recone kits.


Only you hairdresser will know. :banana:

- Yea well, here's your road to Bad Karma ( & ongoing conflict at this forum ) all laid out in front of you .

- Don't follow that road .

- Until you can reconcile this for yourself & get on the correct path / I'd suggest refraining from offering up advice here on related matters .

>< cheers :)

Russellc
06-10-2009, 06:25 AM
:applaud:Physical beauty is highly overrated . . . except perhaps in girlfriends. ;)
That rule gets bent more and more the older I get!:duck:

russellc

Russellc
06-10-2009, 06:28 AM
I think it will be a long time before JBL stop making parts for the popular drivers. I would hate to think how many 2225/2235's there are around the planet.

Allan.

Actually, it probably wont be that long at all. JBL has all but pitched any interest in continuing with these replacement/repair parts. It likely wont be very long at all.:banghead: Search around this forum, its been discussed a lot. Sad but true I'm afraid.

russellc

Loren42
06-10-2009, 07:26 AM
Actually, it probably wont be that long at all. JBL has all but pitched any interest in continuing with these replacement/repair parts. It likely wont be very long at all.:banghead: Search around this forum, its been discussed a lot. Sad but true I'm afraid.

russellc

Yuck!

Loren42
06-10-2009, 07:49 AM
- Yea well, here's your road to Bad Karma ( & ongoing conflict at this forum ) all laid out in front of you .

- Don't follow that road .

- Until you can reconcile yourself on the correct path / I'd suggest refraining from offering up advice here on related matters .

>< cheers :)

http://www.mdbq.net/mistakes.jpg