View Full Version : L 100 t issues with mid and tweeters

03-04-2014, 11:44 AM
Hi all,

It's been a couple of years since my last JBL adventure, here we go again!

I bought a pair of L100t speakers brand new in the late 80's. They departed from my custody along with my ex wife. Last summer, 20 years later, she was moving and asked me if I wanted the speakers.

So I went and picked them up. They were in sorry condition. I just finished the cosmetic restoration and plugged them in. It seems the high end is totally missing. I think one of the mid range drivers does not work at all and both tweeters seem really feeble.

I've measured the impedance of each driver. The tweeters measure 4.4 and 4.5 ohms respectively. The offending mid driver reads 4 ohms. So the drivers appear to be ok. Unless I can have blown drivers with measured impedance.

I pulled the big drivers out and had a look just to see if any wires were unconnected but it all looked ok.

So I assume I should be looking at the crossover arrays? Recapping them? Thanks for any suggestions.

I've done some searching and find references to rebuilding the crossovers to t3 specs, but I would just as soon keep it stock. I remember loving these speakers when they were new, and although no doubt I have lost some of my upper frequency hearing in the last 25 years, these still need a lot of help at the present moment.

Cheers all!


03-04-2014, 03:59 PM
I've seen more than a few drivers with OK DCR measured, that didn't work. Until proven otherwise, assume the drivers are toast. Easy enough to check them out of the box with a direct connect to some input. I'd expect a crossover that passes a visual inspection to at least make some sound.

03-04-2014, 04:18 PM
The attached L100T tech sheet may prove useful. I've found my L100t pair to be a nice balance of size and sound. Replacement tweeters and mids come up on eBay regularly. Although if I were looking for replacements I'd start with a query on this site.

Hope you get yours up and running soon.