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JBL L-100A Century crossover options/help

Kenny Green said:
Hi
Really nice work man, very nice
Minor shifts in tint are normal with anything that starts life out with a recipe and in a barrel
Look like new now like they always do
Nice save on that dome, what adhesive do you use on the Q-tip?
Kenny
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Thanks Kenny! Yea the color isn’t bad they look great to me. :)

I use a small drop of hot glue from a glue gun. Dip the tip of a tooth pick or cut end of a Q-tip, or pretty much anything you can use.

Have pulled many dented dust caps out this way, paper, plastic and cloth, works like a charm. :)
 
Kenny Green said:
Clearly
Sweet fix, thanks for sharing it
You got mad skill dude
Kenny
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Thanks Kenny :) I wish all audio work was as easy as speakers lol I enjoy restoring gear as a side hobby. I can’t wait to take care of the cabinets on this set, wanted to over the weekend but I got busy.

I actually played some closet Tetris today, put some other speakers in my storage unit, and set the 100s with the 166s. I hope to start the cabinets this weekend. I have some new binding posts on hand. I want to listen to them but don’t really have the space, need to move some albums to set them up. I’ll clean the L-pads and install the new binding posts this weekend if I can. Pull out some block stands and give them a go.

I’ve been looking at a few different crossover designs too. Was looking at Kenrick Sound. I’ve actually talked to Kenji via email a few times. Going to email him again to see if he suggests just using some nice caps or if he has designed a XO for the L-100s. I’ve seen a few of his L-100 builds and he usually just uses the Jantzen Super or Silver.

To much to do, and so little time lol I still need to break the seal on the woofers. I’ll do that when I put the tweeters back.

I need to get replacement grills too, and a white peg or 2 as one is loose and the other is gone. I’m just happy I was able to get them in the closet for now, got tired of not being able to reach my system due to them being on my living room floor. :)
 
Kenny Green said:
Hi
Meant to say this yesterday
That's a FANTASTIC save on the douchie edge hack
I've had to deal with the same **** myself
I'd keep that as a resume builder
I'm sure now with the fresh glue and foam n the RIGHT side of the cone that it's functionally fine
What technique did you use to get the dumb ass' edge off and what type glue did he use?
Kenny
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I used dental picks to get an edge lifted. It looked like he used the Simply Speakers stuff, didn’t apply it properly as there was gaps in the seal, I was able to get a lot off but it did cause some paper damage. Nothing bad. For the basket I had to use a blade, and some acetone.

039B1102-295D-4187-B629-3F3D82EB5B5C.jpeg EAB2D24B-0C62-4E93-B698-55E5A519C143.jpeg

Some cotton balls and some acetone gets it really clean, this helps when you go to attach the new surround.
 
Kenny this happens a lot even from pro reconers , they take shortcuts or are just ignorant. No matter the driver the problem is the same and the repair metod is the same.
You need to gradually dissolve the adhesive and gradually release the foam , keeping it apart from the cone so it dosn't stick back down again. Hence the toothpicks. There will usually be glue residue on the front face of the cone but again care and patience with buds and MEK or Acetone will usually clean things up.
 
These days I would be looking at going fully active. DSP units are very affordable now and the world is awash with good used power amps.. Yam's can be had for low dollar and there's plenty of Crowns out there.
If you don't fancy DSP look for a JBL/Urei M553.

With DSP you could start out emulating the original network , save those settings and develop from there .
 
Macaroonie said:
These days I would be looking at going fully active. DSP units are very affordable now and the world is awash with good used power amps.. Yam's can be had for low dollar and there's plenty of Crowns out there.
If you don't fancy DSP look for a JBL/Urei M553.

With DSP you could start out emulating the original network , save those settings and develop from there .
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3-way gets more complicated in the DSP / tri-amp world, and more expensive, but I agree that re-designing and building a pair of new 3-way passive crossovers is of marginal use these days. Kind of like when Chuck Yaeger once was asked why he doesn't have fast cars: "when you've done it in 3-D driving a car really isn't that exciting" (I might be paraphrasing but it is the essence of what he said). Building a really good 3-way passive crossover for a speaker that doesn't even have the ability to get the HF and LF of today's music, has alignment issues, and generally is valued for the nostalgic style and sound? If you do, you at best end up with a speaker that needs boost/equalization on both ends and shaping in-between, and has phase-distortion/delay problems added by the crossover, which should be measured and corrected by a good DSP or other active device. Although it costs money to go tri-amp, or even bi-amp with a crossover just for the MF & HF, it is well worth it IMO.

Or, you have a classic speaker that sounds as it did when it was introduced, was popular, and was the home version of a very popular monitor used to monitor/mix much pop music of its era.
 
Well put Jeff. Funnily enough I have the driver set from some 4312's. I'll build boxes in the usual size but from Baltic Birch. Yeah it would be a breeze to implement the original X/O such as it is but my leaning towards active goes back as far as the late 70's when L40's became available. Amazing improvement. It's been my dirty habit ever since.
 
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One of the other benefits of DSP is of course the ability to apply room correction.

Possibly one of the most important aspects of domestic Hi Fi.
 
It is often hard to "bite my tongue" when I see someone talking about how he should have $4,000 speaker cables and can hear the difference, ... when there's never been a calibrated mic in the room to measure response and correct for it. Once you are able to measure speaker and in-room response and damp the major reflections, correct response, it is hard to hear a system that is running raw.
 
SaturationPt said:
It is often hard to "bite my tongue" when I see someone talking about how he should have $4,000 speaker cables and can hear the difference, ... when there's never been a calibrated mic in the room to measure response and correct for it. Once you are able to measure speaker and in-room response and damp the major reflections, correct response, it is hard to hear a system that is running raw.
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I suppose if anyone spent $4K for speaker cables, he/she is not going to say they were a waste of money. Certainly, I wouldn't admit it. :idea:
 
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