Sub1500 How to tell if yours was manufactured incorrectly

[jarrods]

I have posted before on the detached spider in one of my Sub1500 drivers. I imported some Loctite 770 primer and 422 glue and completed the reglue of the spider today. It was detached from the frame about one half of the way around so I glued that back first then after it had dried I attempted to lift the remaining attached portion as I wanted to reglue it. I can tell you the orange glue used has next to zero strength. Running a screwdriver around between the spider fabric and the frame was not an effort at all and the spider just lifts with the brittle orange glue just chipping off in chunks.

I had a L/R pair of Sub1500’s running when it was damaged. I had one spare so I replaced the damaged one until I had the time to look into fixing it. I decided to take out the other driver today to see if it had suffered any damage at all but it had not. I took out the replacement driver and I see that it is starting to detach as well and it has never had anywhere near the same volume of bass through it as the other ones.

So what is the difference? Well the driver that has not failed has clear glue and the two that failed have the orange glue. I made a bit of an attempt to lift the spider on the clear glue one and no-way… I am sure I would tear the fabric before the glue parted.

Failed drivers are J864-05314 and J866-05940. The good one is J864-06001. It would be interesting to see if all 06000 series have the clear glue.

[Mr. Widget]

It would be interesting to see if all 06000 series have the clear glue.I have only used 5 of the many Sub1500s that I purchased. I still have 6 on the shelf that haven't been powered up. The rest I bought for friends and many of them have yet to be powered up. One of the first two I tried did fail very early on and I had it replaced by Parts Express. So of the five I have used only one failed. I may have other failures awaiting in the sealed boxes so I will be curious how your repairs go so please keep us posted.

I have noticed that some of the woofers that I have, have a very tidy glue line and the glue is clear. On the others it looks like they were already redone with a cream colored glue and it is rather messy. Unfortunately I didn't keep track of the serial number or notice the color of the glue on the one that I had that failed... it was exactly the same failure as you have experienced.

I just looked at the two Sub1500s that were the easiest for me to look at. They both had the tidy clear glue. One had the serial number smudged off so I couldn't read it and the other was #J864-05493.


Widget

[spkrman57]

They don't seem to have any problems that I have come across!

Ron:p

[johnaec]

I've still got two Sub1500's in the boxes - never even opened. But the one I use for live bass guitar has held up very well - hours of high-volume playing - really stressing it. I'll have to check on the glue color...

John

[Mr. Widget]

All manufactured goods have a percentage of defects... as far as we know very few of these have actually been glued improperly and failed... hell one of our forum members abuses his Sub1500 by playing his bass guitar through it... certainly not an application ever dreamed of when these were being designed for Revel. The fact that he can do that and not blow it up is amazing to me.

Lucky? I've compared the two... The Sub1500 is way better in a home environment... you may need a couple of them to keep up with a 2242, but they work in more reasonably sized boxes and they sound better...

If you need maximum SPLs then the 2242 does win hands down... for me loud is great... crazy loud just isn't needed.:D


Widget

[Mr. Widget]

John... you were posting while I was using you as the poster child for JBL abuse!;)


Widget

[johnaec]

John... you were posting while I was using you as the poster child for JBL abuse!;):D And that's with 900 watts rms @ 4 ohms! It was the only speaker I found capable of putting out enough at 40 hz to fill a club with a single speaker, (in a reasonably sized cabinet). 'Latest gig was past Tuesday - 4 hours straight with 15 minute breaks on the hour. It's currently in a 4628B cabinet, (8" 2118H for mid-bass), and soon will be in a special cabinet with an E110 instead of the 2118H.

John :rockon1:

[grumpy]

2 PE sourced SUB1500's, presumed same run:

J864-05520,4 - clear glue, drivers broken in, no apparent separation between
spider and frame.

Clear glue blobs tacking leads to back of cone - one may eventually need
re-tacking; glue has cloudy areas, perhaps indicative of stress (personal
guess). No audible issues. Not grumpy about this purchase :D

-grumpy

[Mr. Widget]

For those that may be concerned... you will know if you have a problem... it isn't subtle. Basically these woofers are either fine or they are screwed up. Most seem to be fine.

Still awaiting Jarrod's reply on how his repairs went. He told me that he glued them last night and was going to let the glue dry overnight before testing them... fingers crossed.


Widget

[jarrods]

Well I have just tested both drivers. One is fine the other is not.

The one that had the dislogment of about one half of the spider now has a scraping sound at moderate levels (using Cobb's 30 Hz speaker refoam tone). My guess is that when it tore out the voice coil assembly hit into the magnet and has deformed it.

The other that had only lifted in about less than one quater of the spider seems to be fine.

Jarrod

[Mr. Widget]

I'm sorry to hear that you were only 50% successful.:( But, thanks for your report... I will definitely physically inspect all of my additional Sub1500s before putting them into service and I'll follow that up with some sinewave sweeps before really driving them hard.

So for the record, both of your defective woofers had an orange glue instead of the clear glue, right?

Has anyone else had a defective Sub1500? If so, what was the color of the glue?
Thanks,


Widget

[Mr. Widget]

For others who may be concerned about these woofers. I use one pair in large (5 cu ft) ported enclosures in my HT... they are powered by a 600wpc amp (1 channel per woofer) and occasionally during particularly violent deep bass soundtrack moments I have had them bottom out... over the years I must have had this occur 10-15 times... before this occurs my fairly large room is inundated with intense earthquake level sound pressure and the smacking of the woofer bottoming out is quite loud... so far no damage that I am aware of.

It is quite frightening to hear. These woofers are not wimpy or frail...I keep meaning to put an infrasonic filter in line... but I haven't done it.

As far as I am aware the few Sub1500 woofers that have had problems are simply manufacturing defects.


Widget

[jarrods]

Hi Widget,

Yes both the orange ones failed and the clear one was ok. I did some more probing around with a small flat blade screwdriver this morning before remounting them. The overglue (out past the edge of the spider onto the frame) chips off very easily in fragments (like toffee snapping) away from the crickle finish of the frame for the orange glue. The clear glue seemed to be very stuck to the frame (like silastic to glass) and I wonder if I kept forcing if the glue would part from the crackle paint or the paint from the metal. btw This is a real issue on these drivers as the spider is glued to the crackle paint finish and NOT to bare metal.

I run these with a Crown K2 (800W into 4ohm) and have never had them bottom out. I have never played my system to the level that I think it could go and honestly the volumes of Janet Jackson song that damaged mine was nowhere like the levels I have heard my brother push his 4435s.

I know that the faulty drivers would fail way under the peak power they should handle as I have manually lifted the rest of the spinder and the glue parted so easily I am surpised they did not fail first time I turned them on.

Jarrod

[Mr. Widget]

I know that the faulty drivers would fail way under the peak power they should handle as I have manually lifted the rest of the spinder and the glue parted so easily I am surpised they did not fail first time I turned them on.Exactly my point... these things can be seriously abused... that is unless you have one of the ones that were f****d up on the assembly line by some idiot who obviously grabbed the wrong glue.:(

Thanks for the confirmation... we should all keep an eye out for the orange glue before putting any of these woofers into service... if they haven't already been played hard.


Widget

[Shane Shuster]

I had serial number J864-05446 fail in the same way. The glue was the orange color. I've used J864-05444 for about a year with no problems. 2 others are sitting in the basement. I recently bought a 4645c and like it much better than the sub1500. In my small room it seems to have less distortion and a cleaner sound.

[Mr. Widget]

2 others are sitting in the basement.I hope they have been stored vertically... the cones are quite heavy and if they are sitting flat the suspension will start to sag with time.


I recently bought a 4645c and like it much better than the sub1500. In my small room it seems to have less distortion and a cleaner sound.That's interesting... I wonder if it is due to the boxes your Sub1500s are in or if it's simply a matter of liking a different sound. I have a definite preference for the Sub1500... the two woofers certainly do sound differently... I suppose there is no wrong answer.

How were you using your Sub1500(s)?

Widget

[Shane Shuster]

I hope they have been stored vertically...
How were you using your Sub1500(s)?

Widget
They are stored vertically. I used them in 3cu.ft sealed and 4.5 vented to 20hz. They are very nice drivers but they have a mechanical chuffing sound when pushed hard. In the sealed box they had a touch of the stored energy kind of sound. My room is very small (9.75 x 12ft) which is probably why I like the 4645c and you like the sub1500. We also may listen to very different types of music and movies. I think that is a big factor not often thought about or discussed.

[John]

I hope they have been stored vertically... the cones are quite heavy and if they are sitting flat the suspension will start to sag with time.

Widget

Hi widget Are you saying that if they are stored in their factory shipped boxes face down they will sag?

I would think that the stryfoam bottom contained in the box would be designed to hold the cone and spider in the correct position in storage.
If storing them face down would damage these drivers, would JBL not have indicated this on the factory carton and recommend storing the box in a vertical position? Would this not also be the case with all coned woofers and mid drivers?

[Mr. Widget]

All woofers should be stored on end. These woofers more than most as the cone is so heavy. I have purchased some woofers from other brands that do have foam inserts to support the cone. These are accompanied by many warnings to remove the inserts.

JBL may have similar packaging for some of the woofers that they sell as components. These were never meant to be sold to the public. They would have always been under the control of JBL and typically they get loaded into cabinets right after manufacture... just in time manufacturing processes...

Anyway, I keep most of mine vertically and the few that I don't, I flip the box every other month. If you have some that are sagging you might flip them and wait a bit, I'd expect they will recenter.

Widget