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Audioduck
09-07-2013, 12:31 PM
Hi All,

I've just acquired a pair of VERY poorly JBL 4411 monitors that I have decided to put the effort into (pics to follow).

I learnt from the previous owner that he'd been running them without any surrounds in one of the woofers *sigh*.

Having got them home and up on the bench I decided to isolate the woofer and test the impedance to see if he's done any damage to the coil. Alas, I can't get the ruddy driver out of the enclosure!

This is my first experience with JBLs (previously only being a Mission, Tannoy or AR chap) so I don't know if there's a particular technique that needs to be employed. Is there? I've had a good look and I can only see the four screw/bolts. Would the factory have secured the driver with some sort of filler or caulking between the driver and the enclosure

It seems to be a bit of a recurring issue:

http://www.audioheritage.org/vbullet...r-removal-Help (http://www.audioheritage.org/vbulletin/showthread.php?21452-Classic-Studio-Monitor-woofer-removal-Help)!

http://www.audioheritage.org/vbullet...178#post233178 (http://www.audioheritage.org/vbulletin/showthread.php?23270-And-now-for-my-4311B-s&p=233178#post233178)

http://www.audioheritage.org/vbullet...woofer-removal (http://www.audioheritage.org/vbulletin/showthread.php?24038-L100-woofer-removal)

Which way to go?

I've tried tapping. I've tried wheedling at the edge with a screwdriver (reluctant to damage the enclosures any more than they are).

Where next?




Also, do any of you have a schematic for the crossover of the 4411 with capacitor requirements? I'd like to recap as these poor boxes to bring them up to date.

Cheers,

Matt

jbl
09-07-2013, 01:40 PM
Greetings, The gasket on the rear of the woofer tends to 'glue'the woofer to the basket. You'll need to gently pry the woofer out. Good advise in those links.

macaroonie
09-07-2013, 03:18 PM
Hi All,

I've just acquired a pair of VERY poorly JBL 4411 monitors that I have decided to put the effort into (pics to follow).

I learnt from the previous owner that he'd been running them without any surrounds in one of the woofers *sigh*.

Having got them home and up on the bench I decided to isolate the woofer and test the impedance to see if he's done any damage to the coil. Alas, I can't get the ruddy driver out of the enclosure!

This is my first experience with JBLs (previously only being a Mission, Tannoy or AR chap) so I don't know if there's a particular technique that needs to be employed. Is there? I've had a good look and I can only see the four screw/bolts. Would the factory have secured the driver with some sort of filler or caulking between the driver and the enclosure

It seems to be a bit of a recurring issue:

http://www.audioheritage.org/vbullet...r-removal-Help (http://www.audioheritage.org/vbulletin/showthread.php?21452-Classic-Studio-Monitor-woofer-removal-Help)!

http://www.audioheritage.org/vbullet...178#post233178 (http://www.audioheritage.org/vbulletin/showthread.php?23270-And-now-for-my-4311B-s&p=233178#post233178)

http://www.audioheritage.org/vbullet...woofer-removal (http://www.audioheritage.org/vbulletin/showthread.php?24038-L100-woofer-removal)

Which way to go?

I've tried tapping. I've tried wheedling at the edge with a screwdriver (reluctant to damage the enclosures any more than they are).

Where next?




Also, do any of you have a schematic for the crossover of the 4411 with capacitor requirements? I'd like to recap as these poor boxes to bring them up to date.

Cheers,

Matt


Either bathe the rim joint to the baffle with WD40 , let it soak and it should lift free OR some have used gentle use of a heat gun ( careful !! ) or a hairdryer ( Knock yourself out ). Basically the prob is the oils in the paint become a 'glue ' and stick the driver in place. Softening , whether by gentle heat or by solvent will do the job.

4411 data and network is here http://www.jblproservice.com/pdf/Studio%20Monitor%20Series/4411LR.pdf

59999

rdgrimes
09-07-2013, 09:26 PM
If you pull the tweeter, you should have access to the back of the woofer for tapping on it.

Maxwelhse
09-07-2013, 09:54 PM
I'm not familiar with the 4411 specifically, but this is what I do with my JBLs..

1. Remove bottom 2 screws

2. Significantly loosen top 2 screws.

3. Tilt cabinet around 30 degree toward you.

4. With the palm of your free hand give the top of the cabinet a couple of good whacks.

The driver should pop right out. Reduce the incline to a more manageable angle (you could slide a couple of books under the cab if you wanted to use both hands) and remove the top screws... At that point, if you've been careful about all of this, you should be able to pluck the driver from the cab w/o issue.

4343
09-07-2013, 11:11 PM
I recently replaced one of my friend's 128H woofers in one of his 4411's. He had them precariously balanced on tripod stands behind the drum kit in his studio. So while balancing the box on the drum throne I was facing the same problem. Woofer had become stuck to the O-Ring, and O-Ring was stuck to the cabinet. I had thought ahead and come prepared with not only the require screwdriver, but a small putty knife. Pushing the knife straight in against the rubber O-Ring can break the bond on one side or the other. I was able to rotate the whole box on the drum throne and by the time I had gone 3/4's of the way 'round it had come free.

Audioduck
09-08-2013, 04:13 AM
Thank you all for your suggestions! A combination of them all (over a period of time!) worked for me.

Now to get these things sorted. I'll open a fresh thread showing my progress.

Thanks,

Matt

macaroonie
09-08-2013, 04:22 AM
Proper job :D

This bloke is good for caps and suchlike. Well informed , that helps a lot .

http://www.audio-components.co.uk/