jbl l100 century l-pad question

[crazyguy99]

howdy yall. quick disclaimer i'm very new to vintage audio gear. that said i recently acquired a pair of l100 centurys. brought them home and noticed that on one of them the tweeter and midrange weren't producing any sound. took them in to my local repair shop, they fixed the tweeter somehow but informed me that the midrange was shot.

ordered a new midrange from ebay but after some research decided to remove the woofer and take a look around myself. i'm not sure they did this at the repair shop because when i looked inside at the crossover the cap on the midrange l-pad had (somehow) fallen off on its own. somewhat disconcerting. the l-pad itself looks unusual / sort of dark. can't tell if it's burned or just rusty.

i'm supposed to get the new midrange this week. my question is: once i get the driver should i hook it up and see if it works? or given what i've said about the l-pad should i avoid doing this as i risk blowing this new driver immediately?

i'm sort of hoping i don't have to do foilcal surgery... i just know i'll eff it up lol

 

[markd51]

I'll try helping.
First most important thing is getting all drivers up to snuff. Sure, you can try the install, and test. Just affirm all is working before you crank the volume dial.

Check L-Pads for operation. L-Pads can often be cleaned up with some deoxit, without resorting to surgery. No it's not easy, you have to be part contortionist and tech all rolled into one. And you might save such parts.

Caps and whatnot on the crossovers, etc. Sure, they would likely benefit from a check and possible needed re-cap.

There's many ways to go about such. some are the right ways, and some are the wrong. I wholly understand cost outlay, versus all else.

The end goal-game is to keep them as close to stock as possible.

 

[crazyguy99]

I'll try helping.
First most important thing is getting all drivers up to snuff. Sure, you can try the install, and test. Just affirm all is working before you crank the volume dial.

Check L-Pads for operation. L-Pads can often be cleaned up with some deoxit, without resorting to surgery. No it's not easy, you have to be part contortionist and tech all rolled into one. And you might save such parts.

Caps and whatnot on the crossovers, etc. Sure, they would likely benefit from a check and possible needed re-cap.

There's many ways to go about such. some are the right ways, and some are the wrong. I wholly understand cost outlay, versus all else.

The end goal-game is to keep them as close to stock as possible.

thanks so much for the response!

totally hear you on keeping them as close to stock as possible, that's definitely my goal. the mid i ordered was mint oem. winced a bit at the price but i'm more put off by the idea of using anything else.

what's the best way to test the midrange when it arrives other than the multimeter test? it's funny, to my untrained ears they sound almost fine without it.

concerning the l-pads: the "working" 3 all crackle. i'm going to order some deoxit to clean them ( through the woofer). i was wondering: is it possible to de-solder them/remove them from the crossover for cleaning/repair without removing the entire crossover? what exactly is holding them in place?