Sub1500 problem (again)

I just noticed a rattle in my RHS Sub1500 so I dropped out the driver for a look. The first thing I checked was the spider attachment to the frame as that is what detached in a previous driver I had.

http://www.audioheritage.org/vbulletin/showthread.php?2558-Sub1500-problem&p=86529&viewfull=1#post86529

This one uses the white glue (not the suspect yellow glue) and the attachment to the frame was fine. I reconnected to the amp and fed in the 30Hz alignment tone I use for re-foaming and with a torch I could see the spider detaching from the central voice coil former. So white glue is a bad as yellow.

I still have some Loctite 422 in the fridge from previous problem (which I still use for odd jobs) but as it is now 4 years old I better get some new glue. I have seen 5019 recommended here but data looks very similar to 422. Any other suggestions?

http://www.loctite406.com/template/ying/pdf/docs/5019H-EN.PDF
http://www.sjgogo.com/pdf/422-en.pdf

Pictures below are 1) normal & 2) with finger lightly pressing spider down.

That is really unfortunate. I just purchased a pair of JBL Sub1500 from the original owner that are still brand new and in their unopened original box - I just hope I don't run into a problem like this down the line. I really wanted to try them after reading positive reviews here at the forums. Have other members had quality issues with their Sub 1500? If that is the case, I might just sell mine without ever even giving them a try.

...and I would gladly buy them without giving them a try...

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Originally Posted by dkalsi

That is really unfortunate. I just purchased a pair of JBL Sub1500 from the original owner that are still brand new and in their unopened original box - I just hope I don't run into a problem like this down the line. I really wanted to try them after reading positive reviews here at the forums. Have other members had quality issues with their Sub 1500? If that is the case, I might just sell mine without ever even giving them a try.

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from some light reading, seems to be somewhat common...

i think the deal here is that folks are more than happy to deal with a little inconvenience
for the absolutely smoking deal they got on them from parts express way back when....
given the performance the units are capable of...

is my read on the situation....

Quote:

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Originally Posted by dkalsi

. Have other members had quality issues with their Sub 1500? If that is the case, I might just sell mine without ever even giving them a try.

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Yes others have had same problem and I am starting to think the great price Parts Express could offer was because they were rejects from JBL or a batch with suspect glues.

That said; I think you should use them. They are a great speaker. Give them a good run in then and then take them out and have a good look at the spider join to the frame and to central former.

If you wish to sell them there will be plenty of buyers. I may need one to replace this one if damage has been done to the VC like last detach. My brother wants one and a friend two. We are all in Australia and freight of a single Sub1500 is now over USD$250 since USPS stopped their surface post service. Even this high freight overhead will not stop us trying to get our hands on some :-)

Oh and I decided to go for the Loctite 382 glue and have ordered it. It has about the same shear stength as the other two other types I mentioned above. It's viscosity is double (good so it will not run down into the voice coil and glue it into the gap :)). Its bond gap is 0.2mm not 0.05mm like the other two which will be good as I am not sure how I can get a small glue gap trying to work in such a confined area.

Quote:

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Originally Posted by jarrods

Yes others have had same problem and I am starting to think the great price Parts Express could offer was because they were rejects from JBL or a batch with suspect glues.

That said; I think you should use them. They are a great speaker. Give them a good run in then and then take them out and have a good look at the spider join to the frame and to central former.

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I bought over twenty of them for myself and a few friends. As far as I know there are now only two of that original order that have not yet seen any signal applied and of that order I only had one fail. I was fortunate in that it failed very early and I was able to get PE to ship me a replacement woofer. I don't know how my friends' woofers or the woofers that I have passed along to others over the years have used theirs, but I have thoroughly beaten the shit out of one pair of mine in largish vented boxes doing HT duty and our late forum member johnaec used one as a bass guitar woofer... none of these have failed.

Obviously from Jarrods' experience and a few other members, some care should be taken during initial run in to make sure your woofers are not some of the few that were poorly assembled. If you have a failure and you catch it before real damage occurs, you can re-glue it and all will be well. Anecdotally though it seems the failure rate has been in the few percent range... certainly under ten percent.

Widget

I had a spider - cone/coil failure although mine was cause by exceeding Xmech and was entierly my fault. I used fairly standard epoxy to repair mine. I was initially concerned about temperature performance of this adhesive as it softens a little above 175 degrees C but it has had a heavy beating since then with no issues. I have six and have had one spider - basket failure which was again epoxied and has been solid.