View Full Version : JBL L-200

08-08-2007, 03:59 PM
I have JBL L-200 speakers. They are about 33 years old.
I think i've managed to damage the horns in these great speakers.
A friend of mine made me a pair of tweeters. At one point, one of them fell from on top of the speaker. Since then, the horns don't work. So my question is how do I know whether it's the horn itself or the crossover? Can I change one without changing the other?
Should I try to find and install new horns or sell the speakers for whatever they're worth and buy something new?

08-08-2007, 04:18 PM
Sure - I have some experience with those speakers - been working with a pair of them lately updating drivers and crossovers,

Well, the big questions are - what are you using for tweeters, and how were they connected?

Generally, your speaker was made as a 2 -way, with an internal network that splits the incoming signal into LF (low Freqs for the woofer), and HF (the high freqs) for the horns.
To add a tweeter you generally feed the HF side of the original crossover to an external crossover that splits the "highs" into Medium freqs (MF) for the horn, and a new UltraHigh Freqs (UHF) for the new tweeter. Depending on how he did it, he may have put the new crossover and new tweeter on top of your speaker, with a line that ran back in to feed the horns. When the new tweeters fell, if that new line for the horns broke/came loose - no signal to the horns.
Might be as easy as just reconnecting the horn wire - or more involved.

Got any pictures or more detailed info??

08-08-2007, 07:48 PM
I'll make some pictures tomorrow,
The way I've got the speakers - there is wires from inside and amps (and tweeters) connected to them. And both horns are dead! Not just one.
Thank you!

08-09-2007, 08:58 AM
tweeter, wires

08-09-2007, 09:17 AM
Okay - your original woofer and horn wires are coming right out the back of the cabinet (around the edge of the original 2 way crossover with the push-connectors and (I would guess) connecting directly to some kind of external 3-way crossover.
Those slot tweeters (JBL model 2405) are the way to go - thats what I added to mine, but I originally had a pair of small speaker boxes I gutted that sat on top of the big cabinets. They held the slot tweeters and a 10" Mid bass drivers when i ran them as DIY 4-way monitors.
I recently I drilled a 3" hole in the speaker "baffleboard", laid the cabinet on its back, pulled the woofer to access inside the cabinets and mounted everything in the main cabinets.




So - what about your external crossover - thats where the loose wires probably occured!

08-09-2007, 10:11 AM
Thank you!
I'll try.
I have Forte preamp, 2 Forte amps and "Audio Control" Phase Coupled Activator (crossover).
Do you have an idea how much will horns can cost me if I need to replace them?

08-09-2007, 10:26 AM
Thank you!
I'll try.
I have Forte preamp, 2 Forte amps and "Audio Control" Phase Coupled Activator (crossover).
Do you have an idea how much horns can cost me if I need to replace them?

I really figure you probably just ripped a wire loose somewhere,
but it just may take some digging to find it and get everything back to normal.

How was all this configured??
With a powered crossover and a pair of amps - its an odd configuration ...
It almost sounds like you are biamping - but - how many amps are in your system?
Forte amps - these folks? http://www.violalabs.com/product.html

What was the signal path in your system?

Signal to preamp to -???

Are both horns dead now?? Thats pretty unusual.
Are the tweeters both shot too?
Maybe they got smacked with a low frequency thud and shattered all 4 diaphrams
(Slot tweeters have diaphrams too!)

Horn prices really depends on how used and what diaphram (aluminium or titanium - factory or aftermarket).
You can sometimes get them used for - say - $200-300 a pair, but they may not match and sound right.
Generally the horns can be rebuilt - diaphrams are available if thats all it is.

08-09-2007, 11:04 AM
I think Forte made by Threshold.
Pioneer Elite to preamp to crossover to 2 stereo amps (one for high one for low). I hope that was an order since during my attempts to find a problem i changed everything for a few times

08-09-2007, 12:04 PM
Here's how I did mine.



And I built my own crossovers with by-pass caps and high quality components (L,C,R). Really made the highs crispy, added definition to the midrange, and helped control the bottom. I was using N1200/N7000s.