noise from my JBL L300'd mid

[karina]

I just brought back my JBL L300 from almost 2 years in restore .
I connect and everything sound good but one of the compression driver (LE83) sound "cracky" at some freq .
It's not clear for me what is the correct impandance of the (8 or 16)?
In this link :
http://reconingspeakers.com/products-page/brands/jbl-le85-diaphragm-2/

It's seems i need 16ohm but i can see other saying 8ohm ....so a bit confusing.

I don't have any intention buying original diaphragms at 360$ (orange county :banghead:),
But from the other hand i don't want low quality replacments for 30$ each.

Heard Radian has high quality diaphragms that can sound as best as the original JBL,
can some one approve it?
Is it complex to replace it by myself?

Thanks!

[hatrack71]

The radian diaphragms are good for the $$. Make sure you get two- so each side sounds the same. They are very easy to replace if that is what the problem is. You may want to get a full set of the red wax seals if you are doing a 100% anal resto. :D The other possibility could be a failing capacitor in the crossover or possibly the polarity is wrong on the diaphragm. Have you swapped the driver to the other L300 to confirm? Have you checked the polarity on the driver in question?

[BMWCCA]

Did you check the L-pads?

Two-years of sitting around can cause them to be a little touchy. Try running them through their full sweep a few times . . . with the system off, just in case. I didn't see any mention of the extent of your restoration is why I mention this. If the L-pads have been replaced already, just ignore me. :D

[ivica]

The radian diaphragms are good for the $$. Make sure you get two- so each side sounds the same. They are very easy to replace if that is what the problem is. You may want to get a full set of the red wax seals if you are doing a 100% anal resto. :D The other possibility could be a failing capacitor in the crossover or possibly the polarity is wrong on the diaphragm. Have you swapped the driver to the other L300 to confirm? Have you checked the polarity on the driver in question?

May be JBL D16R2425 (Ti diaphragm) would be acceptable if for sure the diaphragm is the problem. Its price is about half of the mentioned D16R2421 (Al ).

[more10]

May be JBL D16R2425 (Ti diaphragm) would be acceptable if for sure the diaphragm is the problem. Its price is about half of the mentioned D16R2421 (Al ).

I wouldn't recommend titanium diaphragms. Go for Radian (US made!) diaphragms. Or used JBL aluminium diaphragms, they appear from time to time on ebay.

[BMWCCA]

I just brought back my JBL L300 from almost 2 years in restore .
I connect and everything sound good but one of the compression driver (LE83) sound "cracky" at some freq .

Have you swapped the drivers side-to-side to isolate a driver problem from the crossovers? Elementary I know, but you didn't say.

[karina]

I did play with the lpads - it's not the source for the noise .
No doubt i should change the lpads - can any one recommened on matching lpads?


I'm almost positive it's the diaphragm but not sure which one i should buy ,
As it look most of the recommendation is NOT going on titanum cause of the sonic difference .


Found this page for JBL replacmenets:
http://reconingspeakers.com/wp-content/uploads/2011/12/jbl-le8500011.pdf
But again - in many other threads i found that the correct impadance for LE85 diaphragm is 16ohm when it's in
3 ways and 8 ohm for 2 ways.
So not really sure what should i buy and replace.

[SEAWOLF97]

Have you swapped the driver to the other L300 to confirm?


Have you swapped the drivers side-to-side to isolate a driver problem from the crossovers?




I'm almost positive it's the diaphragm but not sure which one i should buy ,



2 senior members have recommended swapping the drivers , (so I didn't need to) , but that
is the next step b4 you start spending $ .

[Mr. Widget]

But again - in many other threads i found that the correct impadance for LE85 diaphragm is 16ohm when it's in
3 ways and 8 ohm for 2 ways.
So not really sure what should i buy and replace.
I agree with Seawolf... do a bit more work before you start throwing more money on the project.

As for the impedance, you must be reading the wrong threads or you are misinterpreting them.

The LE85 is ALWAYS a 16 ohm driver. I won't bore you with the details, but trust me on this... regardless of what you may read elsewhere including on the foilcals.


Widget

[edgewound]

If the drivers have been in storage it's possible that they have corrosion on the terminals of the diaphragm under the back loading cap, maybe corrosion in the voice coil gap itself and probably rotted foam pads.

Sounds like they might benefit from a thorough cleaning if they've been in idle storage for a while.

[gdwrench]

If the drivers have been in storage it's possible that they have corrosion on the terminals of the diaphragm under the back loading cap, maybe corrosion in the voice coil gap itself and probably rotted foam pads.

Sounds like they might benefit from a thorough cleaning if they've been in idle storage for a while.I 2nd this motion !! ;)