View Full Version : JBL L100 Crossovers


greybeige
08-05-2010, 05:05 PM
If I wanted to buy a second crossover network for a pair of the "original straight-line" L100 Century speakers for re-cap and replace, what would I look for? In other words, are all versions the same or was the network significantly revised as the model evolved?

Zilch
08-05-2010, 07:07 PM
They'd be the ones with inductors in 'em:

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L100%20CENTURY%20ts.pdf

MIA in most all later ones:

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L100A%20ts.pdf

[Build them yourself, better and for less, probably.... :yes: ]

greybeige
08-05-2010, 07:42 PM
Yep I see the difference. Whatever an inductor is, that's a pretty big difference in the network. What is an inductor? What does one look like?

Zilch
08-05-2010, 08:18 PM
In this instance, looks like a small transformer, with just two leads....

Dr. Mordo
08-05-2010, 10:43 PM
Zilch,

Is that the crossover you'd use if you wanted to put a real crossover in a L100?

I hadn't seen that schematic, so I spent a lot of time researching the speakers and their frequency ranges and designed a DIY crossover network with a band pass filter on the mid.

Now I don't know if I shouldn't just build one the L100 with inductors. I sorta do think I'd like to remove the highs from the midrange speaker.

Wayne1
08-05-2010, 11:10 PM
You might want to look through this page for a crossover designed to correct some of the faults of the L-100

L100 crossover upgrade (http://www.troelsgravesen.dk/JBL_L100.htm)

PartsExpress sells the kit Jantzen L100 crossover kit (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-896&FTR=l100%20crossover%20kit&CFID=5573758&CFTOKEN=74625039)

Zilch
08-06-2010, 12:06 AM
Zilch,

Is that the crossover you'd use if you wanted to put a real crossover in a L100?Every time I go through the exercise of designing an upgrade for L100, I end up at 4412s, which are cheaper.

The original L100 crossover might be worth a try, but generally, the bottom line for me is "Leave 'em BE!" It's their shortcomings and colorations that make them what they are -- quintessentially worthy.... ;)

Dr. Mordo
08-06-2010, 06:42 AM
Ok, thanks for the tip.

Copa1934
03-22-2011, 05:53 PM
If I wanted to buy a second crossover network for a pair of the "original straight-line" L100 Century speakers for re-cap and replace, what would I look for? In other words, are all versions the same or was the network significantly revised as the model evolved?
Having acquired L100 drivers cheap I thought about many projects, but the link mentioned earlier has been in the back of my mind for some time. I wish Zilch would have expaned a little on his thoughts (no longer possible of course) as I'm wondering if the jantzen plans are at least a good place to begin? I have L88's that sound nice, but I'm wondering if building a set of L100 (clones if you will) can perform yet better, with or without the jantzen changes.

Has anyone on AK actually tried the mods? Are there any posts of Zilches that reference use of these drivers in a project speaker?

Thanks!!!

MaxSeven
03-22-2011, 07:41 PM
You might want to look through this page for a crossover designed to correct some of the faults of the L-100

L100 crossover upgrade (http://www.troelsgravesen.dk/JBL_L100.htm)

PartsExpress sells the kit Jantzen L100 crossover kit (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-896&FTR=l100%20crossover%20kit&CFID=5573758&CFTOKEN=74625039)

I have those installed on my L100's - much better sounding than before the upgrade.

jlovda
03-22-2011, 07:50 PM
Isn't this kit almost like the tail wagging the dog? It may be terrific but the cost is out of sight.

When I upgraded my L-88P's to L-100's, I started from scratch with two pieces of masonite and built two new ones. I used the "simple" version with no capacitors or inductors in the woofer path. The project also included new L-Pads (tweeter and midrange level controls).

MaxSeven
03-22-2011, 08:18 PM
Isn't this kit almost like the tail wagging the dog? It may be terrific but the cost is out of sight.

Maybe, but the cost matters not :)

Seriously, I think the upgrade is worth the dough - the components are of high quality. Sort of like spending three or four hundred on a new set of tubes, upgrading to a better tone-arm or buying a set of $1K cables.

jlovda
03-22-2011, 09:38 PM
Maybe, but the cost matters not :)

Seriously, I think the upgrade is worth the dough - the components are of high quality. Sort of like spending three or four hundred on a new set of tubes, upgrading to a better tone-arm or buying a set of $1K cables.

It would be interesting to hear what price range Greybeige is in for his upgrade. I hope he keeps us updated as the project goes to completion.

For me personally, all the items you mention above are way out my league. Except for the 16 gauge lampcord to my speakers, everything in my system is used and repaired either by me or Terry Dewick. I must believe there are many more AK participants in my situation. :tears: