Got some new crossovers for my JBL L300s!

Crestwood23

He said touch it in the back
I'm putting some new crossovers in my L300s and I am PUMPED to hear the results. I've re-capped a few sets of speakers in the past, but since I don't know much about the science/art of crossover design I decided to outsource the job to someone who actually knew what the hell they were doing. Lansing Heritage member Duaneage was kind enough to volunteer to assemble these for me. Based on dnewma04's recco (and many others) I went with the Nelson Pass re-designed version of these crossovers. Dayton resistors, Jantzen cross-caps and superior Z caps were used. Duane did these RIGHT with custom etched PCB boards and serious soldering skills! :thmbsp:

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I wanted the option of bi-amping these in the future without getting into external electronic crossover territory, so the crossovers were split into 2 separate boards - one for the HF drivers and one for the LF.

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I got lucky with a bi-amp ready binding post assembly from PE - it fit the existing hole in back of the cabinets like a glove and looks to be a big improvement from the cheesy particle board and old binding post arrangement.

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The biggest pain was getting the "foil-cals" off to install the L-Pads - a hair dryer to melt the glue and a small palette knife did the trick nicely. Does anyone know what glue to use to re-attach them? I was thinking some kind of 3M spray-mount?

I got one speaker done last night and was able to A/B between the new and old crossovers. WOW what a difference! :banana: I thought the old ones were good and couldn't imagine a HUGE improvement but thankfully I was wrong. Everything is SO much clearer and less grainy sounding in the HF. The bass is now shockingly well defined too - going back and forth between the two speakers (old vs. new xover) its amazing to me how seemingly blurred together all of the instruments are in the old vs. the new. Needless to say I am blown away and am putting in the second new crossover STAT :yes:. Thanks to Duaneange and dnewma04 for all their help with this! :music:
 
Congrats on the xo's!!:banana:

I would use contact cement to put them back on with. A very fine layer on both sides then wait 15 minutes then stick them on.:thmbsp:
 
. Does anyone know what glue to use to re-attach them? I was thinking some kind of 3M spray-mount?

After all the work I put into restoring my speakers I wanted to mount the foilcals non-permanent. I used two small 1/16" thick pieces of double sided sticky tape. Each only about 1/4" square. It keeps them from falling off. They are not flush so I can easily get under them again to lift them off without damage to the paint or the foilcal.

BTW there were L300s close enough for me to get ("pickup only") and I don't think they sold. But tell me these are no good for a close field situation. 8 feet between my listening chair and the speakers.

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After all the work I put into restoring my speakers I wanted to mount the foilcals non-permanent. I used two small 1/16" thick pieces of double sided sticky tape. Each only about 1/4" square. It keeps them from falling off. They are not flush so I can easily get under them again to lift them off without damage to the paint or the foilcal.

BTW there were L300s close enough for me to get ("pickup only") and I don't think they sold. But tell me these are no good for a close field situation. 8 feet between my listening chair and the speakers.

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Thanks all for the tips and compliments :).
This double stick tape idea is great - I was apprehensive about glueing the foilcals to the cabinets just in case I needed to get back in there. Everything else with these JBLs is so meticulously engineered, I'm sort of surprised the designers opted for this foilcal route :scratch2:.
Think it's OK to use Goo-Gone to remove the excess old adhesive from the cabinet and back of the foilcal? Maybe I'll test a patch of the underside of the cabinet just to make sure it doesn't hurt the black finish.

My listening position is about 8 feet away in my small basement - they are indeed terrible for near field listening :thmbsp:. I'm kidding of course, although I have plans to move them to the main much larger upstairs living room area when I complete my addition in the near-ish future.
 
Duaneage does great work and has been slowly teaching me the fine art of etching crossover boards. Looks awesome!

yank
 
Really cool news; those are among my dream speakers.

Would you mind posting the crossover schematics and component values for anyone who might want to use them down the road?
 
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