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JBL L80T Upgrade

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DenonDan

New Member
I've seen a number of threads discussing a crossover upgrade on the L100T, essentially making it an L100T3. Can the same be done to the L80T? If so, is the upgrade similarly worthwhile?

If anyone has experience with this, your insight would be appreciated. (Where to get parts, pitfalls, results, etc.)

Thanks all,
Dan
 
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No, he is serious. Charged coupling is a technique developed by JBL. It involves keeping the crossover caps charged with a battery, if I remember correctly. It is way over my head, but it would be very interesting to see a full build on your L80T.
 
The link above is where you start. CC is effective double size and double the amount of caps and some 3meg resistors with a 9v battery in the circuit going to ground or negative side of the crossover.

Find a standard crossover schematic on LHF and then find the CC'ed version and compare. You will see the difference between the 2 and will then know how to cc any crossover.:thmbsp:

BTW you could bypass and cc if you want.
 
Obankenobi said:
Sounds very interesting to me. Googled it and can't find any links to charge coupled XO's. Anyone have a link?
Click to expand...

See above links in my previous post. There are no other companies other than Meitner and JBL who are using this technique in speaker/crossove design and its only used in high buck units as costs escalate quickly.
 
Ok, Obankenobi - come clean with the disturbing avatar. Your too much of a newbie to get away with that.
 
DenonDan said:
I've seen a number of threads discussing a crossover upgrade on the L100T, essentially making it an L100T3. Can the same be done to the L80T? If so, is the upgrade similarly worthwhile?

If anyone has experience with this, your insight would be appreciated. (Where to get parts, pitfalls, results, etc.)

Thanks all,
Dan
Click to expand...

I would start with comparing the L80T and L80T3 crossover schematics. Look at what the component differences are. And then decide if you want to muck around with your crossover, or keep your eyes open for a pair of L80T3 crossovers to come up for sale on eBay. They do come up every so often, and can range from $15 to $50 depending on who's selling, and the demand. You should then tweak the cabinets slightly - longer port, a little more fiber behind the tweeter (GordonW suggested that tweak a few years back.) The T3 cabinets are slightly smaller than the plain T versions. I have the L100T speakers and L100T3 crossovers (have not installed them yet), L20T3 and L40T3. Looking to upgrade my L80T to T3 as well...
 
I don't have the L80t's yet because I'm still debating on whether I want to hold out for some L100t's. I'm running L100 century's right now and I absolutely love them. But all the homework I've done says the LXXXt's are miles ahead, typically for a lot less money. Unfortunately I can't find anything local that I can go listen to.

I appreciate all the input. I have had zero luck at goodwill so I'm expecting to pay FMV. Which is why I'm doing all the research.

Thanks for the help.
 
DenonDan said:
I don't have the L80t's yet because I'm still debating on whether I want to hold out for some L100t's.
...
Click to expand...

My opinion is to "never" "hold out." I have regretted a few of those...if you think you can sell it later for the price you pay, why not buy them now? You get to try it out in the mean time, and who knows when the next one will show up...
 
juniorJBL said:
The link above is where you start. CC is effective double size and double the amount of caps and some 3meg resistors with a 9v battery in the circuit going to ground or negative side of the crossover.

Find a standard crossover schematic on LHF and then find the CC'ed version and compare. You will see the difference between the 2 and will then know how to cc any crossover.:thmbsp:

BTW you could bypass and cc if you want.
Click to expand...
Actually one of the cooler aspects of this thread is the enlightenment. Many people have wondered why recapping is such a big deal, the links in this thread help explain to some degree how those caps work and why the "charging" helps further.

Very cool.
 
I'm too much of a noob to understand charge coupling XO's without somebody drawing a schematic for my 240Ti's. Sounds cool though. Already recapped and they made a huge leap.

My avatar's from Zardoz... bizarro 70's sci-fi with Sean Connery running around in a red leather bikini offing hordes with a Webley-Fosberg? Anyone? C'mon, its a classic! ;-)

BTW - L212's on Ebay right now. One of my dream JBL's (that I could actually afford - have to win the lottery to score Everests or K2's)
 
Hah! I told my wife it was Sean Connery. She said doubtful, but if so, surely it is Photoshopped. I said I didn't think so; that Mr. Connery had been in some real stinkers in the middle of his career.
 
Changing over to a CC network is really quite simple. All you need to do is double the capacitor value and add an additional capacitor of the same value. So a 10uf would become a 2 20uf's as an example. All you need then is to connect the capacitors in series and add a 3 meg resistor between them to form a T junction. The other end of the resistor goes to the + on your battery. The battery - goes to ground. Take a look at the schematics referenced above and give it a whirl

Rob:)
 
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