Do you still have these Lee? I don't like to sell things when I put that much work into them.
Have you demoed them to a group of listeners so they can hear the mods vs. stock difference?
JBL L100 restoration and upgrade
- Thread starter leesonic
- Start date
Do you still have these Lee? I don't like to sell things when I put that much work into them.
Have you demoed them to a group of listeners so they can hear the mods vs. stock difference?
Yes, I still have these. They are actually being used after sitting in the closet for so long. I still haven't made any grills for them, but my daughter is now eight, and very respectful of my stuff.
I hear all kinds of little nuaces in music that I've never heard before. It could be the speakers, or it could be the source equipment, who knows? The point is, none of it is super high dollar stuff.
Lee.
Found a pair of pretty nice L166 Horizon, earlier this year. Had Bao, at Speaker Repair Pros redo the woofer (he added Aquaplas to front). He checked the tweeter and mid.
Crossover irons were fine. I replaced the OEM JBL sand caps with Solen PPE caps. I like these in my redone subwoofers, so I bought them even though the sand caps were prolly fine. Took awhile for them to break-in, But, all sounds fine now. I like these speakers, better than my old, trusty L-100. Better med-high clarity and imagining.
Crossover irons were fine. I replaced the OEM JBL sand caps with Solen PPE caps. I like these in my redone subwoofers, so I bought them even though the sand caps were prolly fine. Took awhile for them to break-in, But, all sounds fine now. I like these speakers, better than my old, trusty L-100. Better med-high clarity and imagining.
R Swerdlow
Active Member
I'm not Lee, but I demoed mine a number of years ago to a group of DIY builders gathered at Dennis Murphy's house. At the time, I also had another unmodified L100, one had a damaged woofer, with the original crossovers available for comparison. I did the crossover comparison using single speakers in mono.
Everyone in the room, about 20 or so DIY builders, could easily hear the differences. With the right music, higher mid-range frequencies, such as solo trumpet, could easily demo the overall brightness of the JBL crossover and stimulate its ugly sounding peak around 6-7 kHz.
Is the middle photo of an L166, and is the white cone original? Thanks.Found a pair of pretty nice L166 Horizon, earlier this year. Had Bao, at Speaker Repair Pros redo the woofer (he added Aquaplas to front). He checked the tweeter and mid.
Crossover irons were fine. I replaced the OEM JBL sand caps with Solen PPE caps. I like these in my redone subwoofers, so I bought them even though the sand caps were prolly fine. Took awhile for them to break-in, But, all sounds fine now. I like these speakers, better than my old, trusty L-100. Better med-high clarity and imagining.
"Is the middle photo of an L166, and is the white cone original? Thanks."
No the tech applied the Aquaplas to the front of the cone. Original application is to the back. The cones needed replacing, as the original owner tried a DIY edge-compliance kit --- and failed.
BTW, the tech said (Speaker Repair Pro, in OC, CA), there is only one source of the original Aquaplas compound, at the moment. In Canada. And lacking the original JBL spray gun, he hand applied the compound.
Original cone:
No the tech applied the Aquaplas to the front of the cone. Original application is to the back. The cones needed replacing, as the original owner tried a DIY edge-compliance kit --- and failed.
BTW, the tech said (Speaker Repair Pro, in OC, CA), there is only one source of the original Aquaplas compound, at the moment. In Canada. And lacking the original JBL spray gun, he hand applied the compound.
Original cone:
scoloheros
Super Member
I grabbed a pair of these locally a month or two ago, woofer has a hole it but I found two 123A woofers at a garage sale years ago, still have those somewhere. Nice to have this thread to refer to.
Cylontymany
Super Member
Just had my 100s recapped doing the Dennis Murphy crossovers. I love them and yes you can hear the difference. I listened to them when I purchased them some years back with the original 40 year old crossovers and I liked the original sound but the Murphys really bring the best out of the 100s no doubt!
I don't recall how much the tech added to the recone cost of those 123A speakers. He said the Aquaplas is getting harder to find. At least, the original JBL formula. Prolly best to call him:
http://www.speakerrepairpros.com/services.html
Al Japely
New Member
Lee
After reading your articles on the Murphy crossover update I detailed my L100a's with new grills (used cloth-the orange Quadrex foam too expensive).Rebuilt the grill frame
using walnut sawn and planed to match originals. If you need the 8 pieces of walnut let me know as I cut plenty. Murphy Crossover project next. Thanks to you and R. Swerdlow.
Just put these back into service after too long. Listening to a particularly funky track with some hot rhythm guitar licks, I tried switching between the JBL and the Murphy crossovers.
With the JBL crossovers, the chunky rhythm guitar fills are much more prominent, and for this track, that's a good thing. Playing the same track switched over to the Murphy crossovers, the midrange takes a bit of a back seat, and you can hear the "texture" of the bass guitar more.
Like reversible belt that's brown on one side and black on the other, these speakers give you options.
Lee.
With the JBL crossovers, the chunky rhythm guitar fills are much more prominent, and for this track, that's a good thing. Playing the same track switched over to the Murphy crossovers, the midrange takes a bit of a back seat, and you can hear the "texture" of the bass guitar more.
Like reversible belt that's brown on one side and black on the other, these speakers give you options.
Lee.
Cylontymany
Super Member
I think it boils down to this: Do you want to listen to a classic speaker as it was intended (Designed) or try to improve them with the DM Mod. I went with the mod. Its a personal choice of course. I did the same thing with my HPM 100s.
GD70
Lunatic Member
Very few of us have the perfect listening space, I know I don't! You work with what ya got, and enjoy the music!
Hell I'm constantly experimenting with lots of speakers and limited space. I do things which most would look at and shake their head(lots have) and yet as long as it sounds good to me and doesn't bother the spouse(much) I fly with it. Until I get a antsy again and switch things around, moving things in and out, stacking, pushing into corners, against walls, into the room, etc.
Here's my latest layout, with a couple of JBL's stacked vertically for space saving(I'd rather have them horizontal both for looks and sound) and the AR3's pushed into the furthest corners. Incredibly, they sound amazing like this. In the old days AR3's were shoved into top shelves of bookcases, high up and horizontal, and that was OK. I've had them long enough to know that while they certainly react as much as most speakers to placement, there isn't much you can do to them(or the JBL's for that matter) that can actually make them sound bad to ME. And that is all that I really care about.
Here's my latest layout, with a couple of JBL's stacked vertically for space saving(I'd rather have them horizontal both for looks and sound) and the AR3's pushed into the furthest corners. Incredibly, they sound amazing like this. In the old days AR3's were shoved into top shelves of bookcases, high up and horizontal, and that was OK. I've had them long enough to know that while they certainly react as much as most speakers to placement, there isn't much you can do to them(or the JBL's for that matter) that can actually make them sound bad to ME. And that is all that I really care about.
I recently stumbled over Lee's thread about his nice work with his L-100s. I had replaced the crossover in my old L-100s in 2006 and wrote all about it here http://forums.audioholics.com/forums/threads/the-vintage-jbl-west-coast-sound-becomes-the….25014/. Lee took it to the next step by the complex wiring that allows him to switch back and forth between the old minimal crossover and the new flat one.
To answer some questions that were asked in this thread, the L-100s with the original crossover measured like this:
The same speaker with the new crossover measured like this:
And here is the schematic for the new crossover without Lee's added switches:
Something has bothered me since I first looked at this crossover, C3011, C3031 and C3061
create a capacitive path from the input to ground at high frequencies. Was there something
like a 3-10 ohm resistor in series with C3061 that got lost at some point? Given that the
tweeter no longer has to keep up with the woofer running wide open I'd expect that there
should be some padding on the tweeter.
Anyone know where Dennis Murphy originally posted this design?
The tweeter circuit as is will be a very difficult load.
R Swerdlow
Active Member
I originally posted this design on Audioholics and later on Lansing Heritage. No padding was ever used or needed for the tweeter.
Your question about a capacitive path has been asked before. On Lansing Heritage (post #8), Gordon W said:
I answered him on post #11.
Other than that, I don't have a direct answer to your question. In 2006, when Dennis came up with the crossover, I asked him about that 3.9 µF cap shunt on the tweeter circuit, and if I remember correctly, he brushed it off saying something like "don't worry about it".
Over the years, I and others have built a number of copies of this crossover, and there were never any problems that I'm aware of.
Here is the impedance plot that Dennis had done. It was predicted by LspCAD not directly measured. Remember, the mid-tweeter crossover frequency is at 5 kHz, and is LR 4th order.
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