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Giovanni
01-22-2016, 02:20 PM
Hi all,

I am thinking to update my JBL 4311B I own since over 30 years, first of all I need stands to lift them off the ground, looking for something suitable to raise them 16-20 inches then would like to work on the speakers, first changing the connectors on the back, the original spring loaded ones are quite poor and barely fit the power cables.

First question: I tried a while ago to remove the woofer, unscrewed it but it wouldn't come off, is it somehow glued or what? Do I have to first remove, say, the midrange to apply force from within to take the woofer off?

Second question: once I menage to remove the woofer would it be easy to remove the actual cable connectors to replace them with a new couple?

Third question: I read in some threads here and there about upgrading/updating the crossover components like the mid-high controls as well as capacitors (dunno if this is the correct translation), is that an easy update to perform? I can handle a soldering tool but dunno which abilities are required and which are the expected improvements, also, does it take to remove the bottom pad with the JBL logo which also covers the mid-tweeter caps? Is then it easy to remove-mount it back?

Apologize for my english and for my naive questions, I just love these speakers, I had to work a couple months or more to buy them when I was 14 and they still amaze me with their sound.

Grazie


Giovanni

Wagner
01-22-2016, 03:19 PM
Hi all,

I am thinking to update my JBL 4311B I own since over 30 years, first of all I need stands to lift them off the ground, looking for something suitable to raise them 16-20 inches then would like to work on the speakers, first changing the connectors on the back, the original spring loaded ones are quite poor and barely fit the power cables.

First question: I tried a while ago to remove the woofer, unscrewed it but it wouldn't come off, is it somehow glued or what? Do I have to first remove, say, the midrange to apply force from within to take the woofer off?

Second question: once I menage to remove the woofer would it be easy to remove the actual cable connectors to replace them with a new couple?

Third question: I read in some threads here and there about upgrading/updating the crossover components like the mid-high controls as well as capacitors (dunno if this is the correct translation), is that an easy update to perform? I can handle a soldering tool but dunno which abilities are required and which are the expected improvements, also, does it take to remove the bottom pad with the JBL logo which also covers the mid-tweeter caps? Is then it easy to remove-mount it back?

Apologize for my english and for my naive questions, I just love these speakers, I had to work a couple months or more to buy them when I was 14 and they still amaze me with their sound.

Grazie


Giovanni
You have too many options to be addressed in a single post or thread
Use the "search" function here and you will find hundreds of pages on the subject(s) you have raised
I recently refreshed the networks on my current pair of L100s retaining the stock values and simply adding an additional film and foil by-pass cap of .01mF in value (the original mylar caps from the factory had drifted significantly from their original value(s) in my pair)
I am very pleased with the results
Custom (and very expensive) "upgrade" network designs and kits are available as well; just do a google search and there again you will find a wealth of information, opinions and options
I believe in leaving them stock (but with new caps), especially if you are already happy with them
As for the L-pads, I also believe in a careful and thorough cleaning and lubrication of those if they have not been damaged or burned from being abused
Any scratchiness or drop outs can be cured if the windings are still intact

As for removing the woofer, that has been covered here a 100 times or more as well. Do a search. There are several techniques. What has happened is the sealing O-ring gasket has become stuck to the paint on the cabinet over time. I have a heavy pick with a 90 degree bend on the end which I use to grab onto the frame through a bolt hole. Work and pull in a controlled fashion around the entire circumference of the driver if it is reluctant to "let go". You can also pry GENTLY with a wooden or plastic shim between the frame and the baffle and pop them loose. Do this, using the shim more as a wedge rather than prying on a sharp angle or you may chip or damage your baffle. Work around the driver. Use common sense.

If none of those suggestions work, you can remove the four screws, place the speaker face down on a nice thick towel or carpet, lift the woofer end of the cab up about 8 inches or so and just drop it. The jolt will in most instances "pop" or break the adhesion loose.
This assuming that no one in the past has applied any sort of sealer or caulk in addition to what JBL used, which was nothing but that O-ring

If you will look on the first few pages of "technical" or "do it yourself" there will probably be at least a couple of threads up currently addressing your very same questions

And yes, you will need to remove the woofer to gain reasonable access to the the binding posts in order to change them. It is not a difficult job. Pulling the mid will do you no good as it resides in it's own chamber or "cup"

Have fun
Thomas

badman
01-22-2016, 04:46 PM
Hahaha- you refer him to the multitudinous threads then answer all his questions :)

Good that he got help.

Wagner
01-22-2016, 05:04 PM
Hahaha- you refer him to the multitudinous threads then answer all his questions :)

Good that he got help.
Better that than the "drama queen" blow off that is still common around here but thankfully not as bad as it used to be
Just steered him in the right direction with general information and shared a few of my thoughts on the matter(s) is all
Thomas