Yet another JBL L100 Century story

First, let me say that, compared to the posts I have read on this site, I am not an audiophile. I do appreciate quaily equipment and decent sound. Also, if this is not the right place for this post, please tell me where to go (if you know what I mean).

I purchased my L100's in the early 1970's and have had them ever since. Over time, the cabinets and cubed foam grill deteriorated and years ago a friend put his finger through one of the tweeter cones during a move. The L100's then went into the basement. My wife determined it was time for the L100's to go, but I did salvage the drivers out of them. The original crossover had also gone bad.

I found replacement tweeters from Simply Speakers. I also found a pair of KLH tower speakers at a garage sale. The active drivers were gone, but the cabinets were solid MDF and the L100 drivers fit like the cabinet was made for them. There also was a 12" passive bass radiator. The interior volume of the KLH box is about 3.3 cubic feet.

I could not figure out what to use as a crossover so, before I found the Audio Heritage website, I purchased a three way crossover on Amazon, a Kasun AS-33C-2. I then assembled everything into the KLH boxes and installed bananna plug speaker binding posts also added some batting. I have attached a picture, but it inserted sideways for some reason. Believe it or not, the speakers sound great. I have also ordered the parts to build the crossover network detailed in the plans and parts list found on this website to see how much the sound is improved. I have also tried the speakers with the passive radiators in, and then removing one and covering the opening. They sound better with the passive radiator.

The most useful piece of information I found here was learning that the polarity on my midrange speakers was reversed. I had assumed that red was positive. It made a world of difference after reversing the wires.

They are currently being driven by a Yamaha Aventage 3070 AV amplifier as part of the home theater system. I also kept my old Phase Linear 400 Series Two that I purchased new. It is currently out for restoration and upgrading and I plan on using it as an external amplifier with the Yamaha.

Anway, that is my L100 story if anyone is interested.

I rotated your KLH-100s.

Interesting idea... not entirely unlike the JBL L150. With the engineering resources of JBL, I'm pretty sure the L150 is the better speaker, but if your wife isn't asking you to throw these out and you like the sound, then I guess they are a success.

It looks like you did a tidy job with the conversion. If you ever want to maximize their performance, I'm sure there are those here who could help with with the bass tuning and dialing in the network design.

Thanks for sharing!


Widget

Perhaps a thousand or more stories like yours about having the L100 when audio systems were the centerpiece of the living room, only to part ways and make room for things that don't include old, boxy speakers like your L100 speaker. I think you are on the right track to try out the original electrical circuit in the Xover.

Thanks for the suggestions, and to Mr. Widget who rotated my picture. I may pursue further adjustments after I get the crossover built. I may be just an aging boomer trying to relive my youth, but I am surprised by how many people have not heard quality speakers driven by a good amp. I guess most people are content with a soundbar under their TV or earbuds. The L100's even impressed my grandkids, and that takes some doing.

I have attached a picture of one of the crossovers I have completed for anyone who is interested. They are both now installed and working great! All of the parts came from Parts Express except for the two Air Core 0.4 Ohm 0.67 mH inductors that came from Madison Sound. I am sure that putting the JBL components in a KLH box with passive radiators is some kind of heresy (not to be confused with the Klipsch speaker), but I am happy with the sound.