View Full Version : JBL L100 upgrade advise
AJSki2fly
09-06-2019, 16:53
I would appreciate a bit of advice from a electronics wiz. I have just been given by my best friend a quite good pair of L100's which need a bit of tidying, they are working and sound pretty good.
What I an thinking of doing for now is just replacing the binding posts, easy and replacing the caps. So hear is the question the existing caps are 8uF to mid range and 3uF to the base. Would using 001-0425: 3.3uF 400Vdc Jantzen Standard Z-Cap and 001-0443: 8.2uF 400Vdc Jantzen Standard Z-Cap which are slightly higher by 0.3uf and 0.2uF make much difference?
I will probably use some better internal cable and bypass the variable pads if I need to after testing them.
Thanks
Adrian
graham67
09-06-2019, 22:24
Hi Adrian,
Lucky you, these are great speakers ��. I would strongly advise speaking to Paul at reference fidelity components (RFC). Hr restored the similar 4311 I now own , have a look at the news or whats new thread on his site.
But he is a friendly chap and will give you useful advice even if you decide not to use his services.
Get them restored well and you will have a speaker for life ��
Using the slightly higher values won't make any difference IMO.
Brilliant website for speaker upgrades: http://www.troelsgravesen.dk/JBL_L100.htm
I'd keep them original if I were you. Just rebuild the x-over like for like. JBL knew what they were doing. I don't see the point in trying to make them something that they are not and possibly wrecking what made them great speakers in the process.
AJSki2fly
10-06-2019, 11:42
I'd keep them original if I were you. Just rebuild the x-over like for like. JBL knew what they were doing. I don't see the point in trying to make them something that they are not and possibly wrecking what made them great speakers in the process.
I tend to agree with you Martin. I have been listening to them this morning, not in a ideal position as on the floor tilted up slightly using a large pebble under the front of each. They actually sound quite amazing. A very engaging and dynamic speaker, the bass and low mid is rather special, the obviously are shifting quite a lot of air. I have ordered some replacement caps and better wire, and better binding posts this morning. Once here I will dismantle and carefully rub down each cabinet and deal with the bumps, mainly on 2 rear corners with is lucky, and then treat with some teak oil. I will then rewire and set up. A friend had some suitable hard wood to make some simple stands. I will probably order some new foam fronts, to finish then off, at the moment they have black fabric, that has seen better days.
When I get going I will post some photos as I go along.
Look forward to it. It was those speakers partnered with a JVC amp and turntable that got me into hi-fi, first really good system I had heard, would have been in 1986. Belonged to a mate's father.
AJSki2fly
10-06-2019, 12:38
Look forward to it. It was those speakers partnered with a JVC amp and turntable that got me into hi-fi, first really good system I had heard, would have been in 1986. Belonged to a mate's father.
Funny my friend originally drove them with a JVC amp, he has had them stored for the past 20 years as his wife would not let him have them in the lounge due to size and made him bu some slim line floor standers. They do sound good being driven by my Alnic T1500, they are pretty efficient as well, at half volume things start to get rather loud.
If you want to keep the sound in the original shape, you should not change anything. Speakers like this is made by care to all components - wire as well as caps. Speakercaps lasts for decades, and the inside wire is carefully calculated to match the rest. I tried to better my speakers some years ago, using Rega-cables inside, from the posts to the filter. It altered the sound balance to something i could not like. I put the old wires again, and i am happy with them as they are now.
thingfish
10-06-2019, 13:34
It's that old upgrade path bullshit......
GRASS IS ALWAYS GREENER ON THE OTHER SIDE.:cool:
AJSki2fly
10-06-2019, 16:44
If you want to keep the sound in the original shape, you should not change anything. Speakers like this is made by care to all components - wire as well as caps. Speakercaps lasts for decades, and the inside wire is carefully calculated to match the rest. I tried to better my speakers some years ago, using Rega-cables inside, from the posts to the filter. It altered the sound balance to something i could not like. I put the old wires again, and i am happy with them as they are now.
Mmm interesting, I will think it through, the wires inside are extremely lightweight and thin, although I have no idea what they are made of or their quality. Thanks for you advice.
AJSki2fly
14-06-2019, 13:52
So today I started on the first L100 and removed the speakers which was pretty easy. then I set down to running down the cabinets. Not too bad and with some walnut coloured wood filler I am hoping to get way with not re-veneering them.They have come up quite well, I am just waiting for the filler to firm up on the bottom corners.
The grill cover had some well worm speaker grill material on it, which I removed and scarped the rear of the board. I am not sure whether to by some replacement foams, they are available from the USA but come in at about £300 a pair for decent ones with shipping etc. It would be nice to return them to original though. If anyone knows where to source some at a better price please let me know? I have seen ones from Poland but not sure about the quality, has anyone had any of these? I have some Royal Blue speaker material so for now will probably just recover the grills with that.
Once I have finished rubbing down I will touch up the black paint and then use some Liberon on the cabinets.
https://hosting.photobucket.com/images/o708/AJSki2fly/0/a4452d19-486f-4ada-82cc-307a4433d8e7-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/a4452d19-486f-4ada-82cc-307a4433d8e7)
https://hosting.photobucket.com/images/o708/AJSki2fly/0/74d07c06-d965-4fb8-bcf2-c18df65a9acd-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/74d07c06-d965-4fb8-bcf2-c18df65a9acd)
https://hosting.photobucket.com/images/o708/AJSki2fly/0/1913efa3-9e12-40ff-b65e-6946acf8cc73-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/1913efa3-9e12-40ff-b65e-6946acf8cc73)
https://hosting.photobucket.com/images/o708/AJSki2fly/0/1ddea696-1f6f-4ee2-81a7-9d6b24c8a5aa-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/1ddea696-1f6f-4ee2-81a7-9d6b24c8a5aa)
I'd go for the cheap Polish grilles. How bad can they be? It's only a grille in any case, £300 plus shipping is ludicrous.
I'd go for the cheap Polish grilles. How bad can they be? It's only a grille in any case, £300 plus shipping is ludicrous.
If they were designed to be listened to with the grills in situ, as would befit a domestic loudspeaker, then the grill material (an open foam in this case) might well have been part of the acoustic design. I would tread carefully with their replacement.
I once heard the L100s many years ago in a record shop. They were suspended from the ceiling and playing 'Heroes and Villains' by the Beach Boys. Was very taken with them, to the point that I still remember the experience.
They are domestic version of a studio monitor so fine with no grilles. Not that it makes much of a difference either way.
They are domestic version of a studio monitor so fine with no grilles. Not that it makes much of a difference either way.
OK - but they look so much better fitted with the sculptured foam 'waffle iron' grille. I would choose the brown grille, so it looked like a giant chocolate bar! :D
I like the orange meself. But I wouldn't be paying 300 notes out for them.
Yes, the orange grille looks good. :)
Yes, the orange grille looks good. :)
Agreed ... but, I am stuck in the 70s :D
Quality speakers, Adrian ... good project, well worth the effort imo.
Agreed ... but, I am stuck in the 70s :D
.
In a thousand years time scholars will still conclude that if you were going to be stuck anywhere in time then the 1970s would be the optimal choice.
In a thousand years time scholars will still conclude that if you were going to be stuck anywhere in time then the 1970s would be the optimal choice.
Why? - the fashion was terrible: tank tops, tight fitting shirts, flared trousers and platform heels!
We didn't notice at the time...
Anyway
Best music
Best films
Best telly
Best football
best boxing
best F1
best cars
best summers
best interior design
Anyway
Best music
Best films
Best telly
Best football
best boxing
best F1
best cars
best summers
best interior design
You have to be joking!
AJSki2fly
14-06-2019, 21:24
In a thousand years time scholars will still conclude that if you were going to be stuck anywhere in time then the 1970s would be the optimal choice.
I completely agree with you for once Martin:D, quality music, quality cars, :lol:, and quality times :eek: :eyebrows:
AJSki2fly
21-06-2019, 10:28
So to update my L100 tidy up, here are some pics of the result.
After rubbed down, 3 coats of Liberon, and recovering the grills, and replacing the binding posts with sensible modern ones.
https://hosting.photobucket.com/images/o708/AJSki2fly/0/38f8775d-8872-41bc-b6c7-d25e23a2b921-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/38f8775d-8872-41bc-b6c7-d25e23a2b921)
https://hosting.photobucket.com/images/o708/AJSki2fly/0/e239ef39-6313-43b8-8359-47c984e490ea-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/e239ef39-6313-43b8-8359-47c984e490ea)
https://hosting.photobucket.com/images/o708/AJSki2fly/0/9cdda59a-3276-4a86-bbb6-7a52df1a3975-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/9cdda59a-3276-4a86-bbb6-7a52df1a3975)
Before and after
https://hosting.photobucket.com/images/o708/AJSki2fly/0/299a3b34-715c-4fb1-938a-cb3292897f5a-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/299a3b34-715c-4fb1-938a-cb3292897f5a)
And in the lounge sat on temporary stand made from oak, to get them off the floor and at an angle.
https://hosting.photobucket.com/images/o708/AJSki2fly/0/26aecec4-6975-4c51-b53c-428d006259d0-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/26aecec4-6975-4c51-b53c-428d006259d0)
https://hosting.photobucket.com/images/o708/AJSki2fly/0/da773342-02bc-407f-8ca0-ddd1a5318da2-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/da773342-02bc-407f-8ca0-ddd1a5318da2)
https://hosting.photobucket.com/images/o708/AJSki2fly/0/746f8c0f-336f-452a-99b8-2e8e2f617e6b-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/746f8c0f-336f-452a-99b8-2e8e2f617e6b)
So next it is to make some wooden stands at limited cost. Then I need to source some Walnut beading to redo the grill surrounds ready for replacement Grill Foams. Once I have got the money together then I will order some metal stands and the grill foams.
So how do the sound? So far I have listened to Deep Purple - Fireball and the first disc of Eva Cassidy - Nightbird (7 disc 45rpm box set), R. Strauus - Also Spracht Zarathusa, and Ravi Shankar Portait of a Genius. The Deep Purple just rocks and is alive. Eva Cassidy is definitely not coming out of the speakers but is firmly on the stage playing her guitar. Also Spracht was a surprise, the opening track which many know (2001 Space Odyssey) is quite wonderful, the kettle bells blow you back in your set and the bass from the double basses and the organ just hits you. What is also lovely is that on the second part which has some delicate strings and woodwind the orchestra sounds as if in the room with good instrument separation. The Ravi Shankar is one of my favourite test records, it is great for dynamics with hand held percussion, any array of Inidan hand drums, flute and of course sitar. The L100's certainly bring the music of this record to life in a very natural way.
Well they are pretty impressive for a design speaker that is actually 50 years old, and these were made in the mid 70's. They actually give a rather lovely smooth and engaging rendition. What is surprising in my set up is that even the top end and mid range is very good in comparison to my Vienna Acoustics, I would say that the VA's have slightly more detail at the top end, presumably due to modern tweeter design, but nothing to detract from the overall musical rendition. The bass and low mid is where they are quite divine, they produce oodles of it, it has a very nice warm feel but is still very controlled. The sound stage is extremely impressive as well. Considering they are are just plonked on temporary wooden blocks I am very impressed. Overall a very accomplished and musical sounding speaker IMO.
So IMHO anyone who is looking for an open and uncluttered sound from their system with plenty of punch you could do a lot worse that a pair of JBL L100. I noticed that there is a pair for sale on Ebay with some stands -JBL-L100-Century-Vintage-Classic-Speakers-inc-Stands (https://www.ebay.co.uk/itm/VintageAudioHifi-JBL-L100-Century-Vintage-Classic-Speakers-inc-Stands/333237015328?hash=item4d96795320:g:VXkAAOSwlWBdB7K g) They look a little later than mine but appear to be in quite good condition.
fatmarley
21-06-2019, 15:29
The more you bring them up off the floor, the less lower midrange/midbass you will get (deep bass is omnidirectional so woofer positon relative to the floor doesn't matter). It would be worth experimenting with something tempory to lift them off the floor before spending money on stands, because there's a chance you may not like the result.
Back in the day they were usually on metal open frame stands about 8 inches off the floor and angled slightly up. So you're not far off that deployment now. Although for the full 1970s experience one speaker should be completely behind the couch, firing into it. And a porcelain 'woodland scene' or similar item of tat should be placed on a doily atop each cabinet...
They look excellent after that refurb though. I'm quite jealous.
Pigmy Pony
21-06-2019, 20:37
Back in the day they were usually on metal open frame stands about 8 inches off the floor and angled slightly up. So you're not far off that deployment now. Although for the full 1970s experience one speaker should be completely behind the couch, firing into it. And a porcelain 'woodland scene' or similar item of tat should be placed on a doily atop each cabinet...
They look excellent after that refurb though. I'm quite jealous.
Don't forget a nearly-full ashtray on the one nearest your chair :) I'm really getting to like JBLs, would they work off a 300b amp, or do they need more watts up 'em?
graham67
21-06-2019, 22:34
Great work Adrian ��. Have you got any pics sans grilles?
I have not dissimilar 4311, as you say the upper bass is sublime, I think its one reason they are great for rock as they are made for picking out the bass line.
Don't forget a nearly-full ashtray on the one nearest your chair :) I'm really getting to like JBLs, would they work off a 300b amp, or do they need more watts up 'em?
Depends on what sort of levels you want. They are pretty sensitive so you don't need many watts.
AJSki2fly
22-06-2019, 09:19
Don't forget a nearly-full ashtray on the one nearest your chair :) I'm really getting to like JBLs, would they work off a 300b amp, or do they need more watts up 'em?
I am driving them with a ALLNIC T1500 mk2 which is a SET amp and rated at 12W per channel, I have it just above half volume for proper listening and is pushing out around 80-85dB, which is more than enough. Take it up to 3/4 volume and things in the house start to shake, rattle 'n' roll.:lol:
AJSki2fly
22-06-2019, 09:34
Great work Adrian ��. Have you got any pics sans grilles?
I have not dissimilar 4311, as you say the upper bass is sublime, I think its one reason they are great for rock as they are made for picking out the bass line.
I had to look up sans :doh:, my schoolboy Francáis and old brain stopped working. Hear you go.
By the way just listened to Rickie Lee Jones - Girl At Her Volcano very laid back jazz, piano , bass drums and breathe vocals and the L100's perform superb. I am beginning to think that these are really quite special speakers, and can't think why I did not consider them before, especially as I heard them many times at my best friends:doh:, maybe we just didn't really listen and were just pumping out heavy rock.
https://hosting.photobucket.com/images/o708/AJSki2fly/0/c11702c9-3d8c-470e-8c87-a1bec765a8bc-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/c11702c9-3d8c-470e-8c87-a1bec765a8bc)
https://hosting.photobucket.com/images/o708/AJSki2fly/0/1d3aeda1-e59b-4c05-9e12-273f382bb93b-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/1d3aeda1-e59b-4c05-9e12-273f382bb93b)
https://hosting.photobucket.com/images/o708/AJSki2fly/0/7d4ba79a-42c2-41cc-be3e-1baab82ad990-original.jpg?width=1920&height=1080&fit=bounds (https://beta.photobucket.com/u/AJSki2fly/p/7d4ba79a-42c2-41cc-be3e-1baab82ad990)
AJSki2fly
22-06-2019, 09:42
Back in the day they were usually on metal open frame stands about 8 inches off the floor and angled slightly up. So you're not far off that deployment now. Although for the full 1970s experience one speaker should be completely behind the couch, firing into it. And a porcelain 'woodland scene' or similar item of tat should be placed on a doily atop each cabinet...
They look excellent after that refurb though. I'm quite jealous.
Thanks Martin, I am rather pleased with the result visually and sonically. I think I have some suitable concrete blocks to raise them up a further 5", the temporary stands actually incline them 5 degrees which is what I think it was originally. It actually would not be that hard to extend the current wood stands from and back with simple cross bracing as on them now and attached them with bracing internally, probably only cost about £6 in wood.
I will eventually replace the grills with some funky foam ones, I think they're worth it, and if I'm feeling flush with get some metal stands I have found for £200. But that can what for now.
AJSki2fly
04-07-2019, 14:22
Time for a quick update, I have been listening to the JBL L100 Century's quite a lot, when I changed tone arms recently I switched back to the Vienna Acoustics to listen to some listening track to evaluate the JELCO TK850M. The immediate change is in the bottom end, the VA's do produce quite a bit of low end bass but it just has not got the same oomph as the JBL's. The top end with the VA's may be slightly sweeter but it is quite subjective to be honest. So after a day or so I plugged back in the JBL's and I am definitely enjoying them, they seem to partner well with the ALLNIC T1500 and my TT setup.
Mmm :scratch: where do I go next, well not far I think, finish off the JBL's with some foams and stands and be happy I think.
walpurgis
04-07-2019, 14:26
Mmm :scratch: where do I go next
Bigger JBL's! :)
+1
Trade up from them to some Everests step by step like Mike does in 'Wheeler Dealers: On The Road.'
AJSki2fly
04-07-2019, 16:15
+1
Trade up from them to some Everests step by step like Mike does in 'Wheeler Dealers: On The Road.'
I presume you mean a pair of these?
https://www.ebay.co.uk/itm/JBL-PROJECT-EVEREST-SPEAKERS-DD55000/264375408580?hash=item3d8e0097c4:g:LwIAAOSwXFRcWMV 7
I think I would have to turn the garage into a man-cave music room and install a small wood burner for heating in the winter. So with the cost of these and the garage conversion I estimate a spend of around £20K, nothing to worry about then.:eek:
I presume you mean a pair of these?
https://www.ebay.co.uk/itm/JBL-PROJECT-EVEREST-SPEAKERS-DD55000/264375408580?hash=item3d8e0097c4:g:LwIAAOSwXFRcWMV 7
I think I would have to turn the garage into a man-cave music room and install a small wood burner for heating in the winter. So with the cost of these and the garage conversion I estimate a spend of around £20K, nothing to worry about then.:eek:
No trade up to it, buy better and better JBLs, tart them up adding a bit of value each time then eventually you arrive at the Everest as your last leap. The garage conversion is a good idea too.
No trade up to it, buy better and better JBLs, tart them up adding a bit of value each time then eventually you arrive at the Everest as your last leap. The garage conversion is a good idea too.Nah stop at 4367. That's all you need. It's the only really good contemporary JBL. I'm convinced of it . The Everest just ain't as good even though it should be.
If didn't have the speakers I have that's what I'd use.
Nah stop at 4367. That's all you need. It's the only really good contemporary JBL. I'm convinced of it . The Everest just ain't as good even though it should be.
If didn't have the speakers I have that's what I'd use.
That's like Mike stopping at the Delta Integrale instead of going on for the Ferrari. I mean in reality everyone would stop at the Integrale but you wouldn't get a show out of that.
That's like Mike stopping at the Delta Integrale instead of going on for the Ferrari. I mean in reality everyone would stop at the Integrale but you wouldn't get a show out of that.Stacked Everest's for maximum effect, then. Only then can he have made it.
AJSki2fly
16-08-2019, 14:39
I thought is about time I brought this thread up to date where I now got to with the JBL's and why.
My immediate impression was I was stunned at just how good they were, I had them set them up at the factory 0 adjustments. I did some basic measurements using REW software and they have an extremely good response curve, I used to work in the Wolfson Unit sound and vibration lab at Southampton University many years ago so am reasonably familiar with speaker measurements and what is meaningful. I adjusted the settings a little using the software and my own listening and they improved a bit more.
So having decided they were really good I felt I needed to finish the job and do them justice, so I ordered some replacement foams in dark blue and badges, and I sourced some walnut strips to repair the edging strip on the grill boards as someone had cut them back at some point. I then bit the bullet and ordered some proper stands for them. I complete the grill boards yesterday and the stands arrived this afternoon. The result is pictured below.
I would say the stands have made a change to the presentation slightly, soundstage seems more focused and more 3D, the bass is more defined, clearly evident on my listening tracks 10cc - Worst Band in the World(Sheet Music) and Alan Parson's Project - I Wouldn't Want To Be Like You(I Robot). Interestingly I have listened with the new foam grill on and off and they seem to make very little difference, perhaps slightly better focus with them off. I keep putting on a listening track and then just let it run to see how the next sounds, all very enjoyable.
I am truly stunned by these speakers, everything just sings, and with the recent Belden RCA cable changes it has just all come together. I would recommend them to anyone who like a realistic and engaging sound from their system to give them a go.
https://i.postimg.cc/mDFHGjwy/fullsizeoutput-3d6f.jpg (https://postimg.cc/phRTfD3m)
Powered by vBulletin® Version 4.2.3 Copyright © 2026 vBulletin Solutions, Inc. All rights reserved.