JBL L150a - to re-cone or not to re-cone? That is the question.

Hello -

I just purchased a pair of JBL L150a's and all four "woofers" are totally shot and need reconing, also one of the midranges speakers is slightly dented - I am not sure of the cost to recone/refurbish these speakers - Is it worth it? I plan on selling at some point (perhaps) but do not want to put too much $$$$ into them if there will be no return - To part out or not to part out??????

Thanks for your help and advise.

DAVE

http://www.speakerrepair.com/ocsrepairprice.html

128H: $248 original, $148 aftermarket, each.

PR300: $118. These are listed as a 15", which may be a typo.

These prices are an example of why many folks opt for buying used drivers.

When you say all four woofers are shot, the L150 only has one per cabinet. If you are only talking about the foam surrounds, these can be repaired for a few dollars each.

Allan.

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Originally Posted by Allanvh5150

When you say all four woofers are shot, the L150 only has one per cabinet.
If you are only talking about the foam surrounds, these can be repaired for a few dollars each.
Allan.

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If I recall, there is one woofer and one matching passive radiator (PR) per cabinet.
If the surrounds are shot on all 4, he'd need 4 surrounds for all the "woofers"

Then again, he did say "... all four "woofers" are totally shot and need reconing"

... there is this thread ....

http://www.audioheritage.org/vbullet...ssive-radiator

Attachment 52437

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Originally Posted by hjames

If I recall, there is one woofer and one matching passive radiator (PR) per cabinet.
If the surrounds are shot on all 4, he'd need 4 surrounds for all the "woofers"

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:blink:

I too was wondering is he is talking abt foam surrounds or cones....a quick and easy test with unknown speakers and bad surrounds is to lay them on their backs, firing straight up , so that gravity doesnt induce misalignment and play them (at low volume and not very long)

a passive radiator could also be called a passive woofer , so active + passives = 4
(since you seem confused)

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Originally Posted by Allanvh5150

:blink:

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A woofer would tend to go WOOF. A passive radiator would tend to say "REALLY". :)

Yes -

I am mistaken - What I mean is that the foam Surrounds on the bottom two "speakers" are shot - Meaning the large white cone on top and the large black cone on the bottom - Would it be worth it to just replace the foam surrounds and could I do it myself? Hey - thanks to all for helping me to understand more about what I am looking at - I picked up this pair at a "junk" shop for $25.00. I will take photos so that you can get a better idea of what I am talking about.

Thanks - Again -

DAVE

Here are the images -
Yes it looks to be just the foam surrounds - where can I get those parts and is it relatively easy to fix? Any help or explanations or advise would be greatly appreciated.

DAVE


Attachment 52460

Attachment 52461

Attachment 52462

Attachment 52463

dont let that loose foam from the surround fall out on the rug ...if it gets ground in by a foot, the stain will never come out .....


ask me how I know..:(

If those woofers have been operated in that condition, or even left to sit for years like that, there can be damage to the voice coil and/or spider. That said, it doesn't hurt to re-foam and try it. Obviously the passive radiators will be fine. Please note that there are a couple different variations of the 128H, and they technically should use different surrounds. They are also not the easiest model to "learn" on. For those reasons I'd suggest sending them off for the re-foam. You can learn on the passive radiators if you want to save some $.

Orange Co Speaker is often recommended, I've used them with great success. Local member "edgewound" is an expert and is also highly recommended.

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Originally Posted by Allanvh5150

A woofer would tend to go WOOF. A passive radiator would tend to say "REALLY". :)

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Great one!!! :D:D:D

BTW To check if the coil hasn't rubbed too much and worn thru the varnish, you could lay the woofer on its back and connect a Ohm meter. Move the cone around and see if the Ohm reading changes. If it does, I suspect that the varnish has eroded in some areas of the coil and shorting.

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Originally Posted by Lee in Montreal

Great one!!! :D:D:D

BTW To check if the coil hasn't rubbed too much and worn thru the varnish, you could lay the woofer on its back and connect a Ohm meter. Move the cone around and see if the Ohm reading changes. If it does, I suspect that the varnish has eroded in some areas of the coil and shorting.

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Good idea, but most ohmmeters don't like having the voltage generated by moving the voice coil in the magnetic field applied to them, and will respond by jumping around (in the case of an analog meter) or counting up and down around the correct reading.

For all it is worth, put new foam surrounds on them and see how they go. I have done many in this condition and have not yet come up with a dud. Crank em up and see how they go. Nothing to loose here and if they go OK you will have a damn fine set of speakers for under $100!!!!. Check the voice coils first of course.

Allan.

Quote:

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Originally Posted by Allanvh5150

.....Nothing to loose here and if they go OK you will have a damn fine set of speakers for under $100!!!!. Check the voice coils first of course.

Allan.

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Hello All -

and thanks for all the info - One question - What do I need (tool wise) and how do I check the voice coils?

Thanks -

DAVE