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Repsak2005
08-02-2015, 08:42 AM
I have had a pair of L 110 since 1983 and they have performed flawless until now apart from refoaming the woofers three years ago, after that they worked well again.
Now the woofers have stopped working or rather they don't move, I seem to feel some vibration but not enough to make them move no matter how much power I add.
I've tried to measure all the components in the crossover, the only abnormality are the inductors which seems to show less readings than I have read they should.

Pretty new at trying to troubleshoot, any advise would be more than welcome.

Carsten

Don C
08-02-2015, 10:06 AM
The voice coil must be stuck in the gap. Due to mis-alignment, foreign material, failed adhesive, or overheating. Surprisingly, it looks like official kits are still available. So you could have a professional recone job done.

66228

Repsak2005
08-02-2015, 02:18 PM
Thanks for your reply Don

I can now see that I need to clarify what I meant with them not moving.
The woofers actually move freely without any noise or resistance when moving them manually, but when playing they do not move as they used to do, i.e. no visible movement of speaker cone.

Hence my suggestion that it may be the inductors.

regards

Carsten

Don C
08-02-2015, 03:13 PM
Oh. Can you hear sound coming from them? If not, in this situation, you should get a multimeter and check the continuity of the voice coil.

Repsak2005
08-02-2015, 05:02 PM
Hi again Don

There're sound coming from both woofers.

Also we tried to measure both woofers, they read between 5.2 and 5.3 ohms which I think is within the normal range.

So that seems to be ok?

regards

Carsten

Aaron
08-02-2015, 05:27 PM
Just recently I bought a 112H that had failing tinsel leads that resulted in erratic behavior, sometimes it worked... I was actually able to excavate the old tinsel & put in some fresh stuff to salvage the speaker.
Tinsel seems to be made of something other than just metal so it doesn't have to appear physically broken for it not to work right. You might want to carefully play with the tinsel leads while running an amp directly to the woofer to see if there is any issue them.

Also, Deoxit is the vintage electronics owners friend. Spritz some of that in the high & mid level pots & on slip on connections and wiggle them gently.

Don C
08-02-2015, 06:15 PM
If there is sound, how does it sound? If it sounds OK, I wouldn't worry that the woofers don't move much. Check every speaker by putting your ear right in front, and check everything about the rest of your system. How are the L-pads set? If they are turned up all the way, the woofer might sound like it's putting out too little in comparison to the midrange.

Repsak2005
08-03-2015, 06:02 PM
Hi again Don

There's sound coming from the woofers, it's weak sound but clear, i.e. we can hear the music, it's not distorted or so. I've checked the other components as well, they're fine.
The L-pads are at half setting both for the tweeter and the midrange.

The problem is that there's no bass whatsoever, they normally produce a really good bass with a lot of movement of the cone, now it's just weak music coming out and no bass. I'm not sure as to when this started, they're in my son's room and he plays a lot of games on his pc with the sound going though an amp to the speakers.

We recently hooked up a record player and that's when I discovered the problem.

pretty much at loss to what could be wrong.

Mr. Widget
08-03-2015, 06:34 PM
Try pulling the woofers and connecting the speaker wire directly to each woofer... run the wires out through the ports and screw the woofers back into place. The speakers won't sound right but they should have bass and significant output. If this is the case then the problem is with the crossovers... possibly the L-pads, caps, or wiring. It is highly unlikely that the inductors failed, but it is possible.

Give this a try and let us know what you discover.


Widget

Don C
08-03-2015, 07:29 PM
A turntable is a special case, requiring the correct pre-amp input to sound right. You are hooked to a specific Phono input with a RIAA pre-amp in the system? Could you try a CD player for a while?

Mr. Widget
08-03-2015, 07:47 PM
A turntable is a special case, requiring the correct pre-amp input to sound right. You are hooked to a specific Phono input with a RIAA pre-amp in the system? Could you try a CD player for a while?Excellent point.

I had assumed that your woofer problem was universal. If you have only discovered it while playing records then your turntable isn't connected to a phono preamp.

FYI: There are a number of AVRs, receivers, and integrated amps that have an input labeled "phono", but it is actually only another "Aux" input as they do not have an internal phono section with the proper cartridge loading, RIAA curve, and adequate gain. Check your owner's manual. It will tell you if you need to add a phono section.


Widget

Repsak2005
08-04-2015, 06:12 PM
Good evening guys

So I tried to run the woofers directly from the amp after fitting them back into the cabinet. They seem to work ok, still not a very heavy bass as I remember but much better than running them through the crossover.

I was aware of the requirement for a preamp for the recordplayer, also we have tested them running a CD.

So what I gather from this is that it's likely that the problem is the crossover. So I guess that I have to start measuring the individual components in the crossover?

Thanks so much for your help so far

Don C
08-04-2015, 09:13 PM
Capacitors tend to fail far more often than inductors, though either is possible. Tell us if you serial number on the foilcal ends with the letter A or not, and we can look up the correct schematic.

Repsak2005
08-07-2015, 03:51 PM
Capacitors tend to fail far more often than inductors, though either is possible. Tell us if you serial number on the foilcal ends with the letter A or not, and we can look up the correct schematic.

They end with an "A" and I have the schematic for that. But thanks for your offer anyway, much appreciated.
Now I'm just wondering if you can measure the individual components while they're still on the crossover or do I have to take them off one by one and resolder them afterwards?

regards

Carsten

grumpy
08-07-2015, 04:15 PM
You can probably check gross operation of the components in that section by disconnecting the woofer.
Coils approximating a short and capacitors having very high resistance (once charged).

Checking component values with precision while in-circuit is a fools errand, however you only need
to lift (disconnect or unsolder) one 'leg' of a component to take it out of circuit.

Don C
08-07-2015, 04:36 PM
I'd suggest to have a look at those two caps in the woofer circuit.

Repsak2005
08-19-2015, 07:29 PM
After having swopped out the capacitors for the woofers and added the missing 0.0068 mF parallel capacitor, we checked the speakers again, same result.

Dug out an old amp and hooked it up, guess the problem all the time was the amp my son uses! Must have blown a circuit or something, wish I had thought about checking that first.

Anyway, we have new capacitors in the x-over and working speakers, not bad at all.

Thanks so much for your help and advise

Btw, the schematics for the L110A shows parallel 0.0068 mF capacitors for all components, do they make a lot of difference? They're missing on both x-overs, guess they were removed during a repairs years ago. We added them for the woofers but not for the midrange and the tweeters.

Don C
08-20-2015, 07:23 AM
They are called bypass capacitors. There's endless discussion about them in various threads here. They are probably worth adding if you care about good sound.

4313B
08-20-2015, 08:20 AM
They are called bypass capacitors. There's endless discussion about them in various threads here. They are probably worth adding if you care about good sound.Yeah, for what it's worth:

Bypassed and Biased Capacitors (http://www.audioheritage.org/vbulletin/showthread.php?3555-Bypassed-and-Biased-Capacitors)

Wagner
08-20-2015, 04:15 PM
Yeah, for what it's worth:

Bypassed and Biased Capacitors (http://www.audioheritage.org/vbulletin/showthread.php?3555-Bypassed-and-Biased-Capacitors)
I wish you would please share with me what you did not like about the Dayton film and foils for by-pass use

I have read where you wrote that it was "not nice", but I was extremely interested in knowing just how so (YOUR impressions, exactly what did you not like about them)

I sent you several PMs and no reply; am I on your shit list?

Sorry for the hijack Louisiana; glad y'all got your problem straightened out

Thanks
Thomas

4313B
08-20-2015, 05:31 PM
I wish you would please share with me what you did not like about the Dayton film and foils for by-pass useIf I remember correctly it was the Dayton film and foil in conjunction with some main cap brand that sounded shrill and harsh. It wasn't subtle. I believe the Dayton film and foils worked just fine with a different brand of main capacitor, I no longer remember which. I do distinctly remember liking the AudioCap Thetas.

For what it is worth I didn't liked the sound of the Solen capacitors either until I started biasing them. I was kind of dubious of G.T.'s suggestion that I would like them charge-coupled, how does one spin gold from straw right? Needless to say, he was right. Go figure...

Come to think of it, he has never steered me wrong.... :hmm:

Wagner
08-20-2015, 08:06 PM
If I remember correctly it was the Dayton film and foil in conjunction with some main cap brand that sounded shrill and harsh. It wasn't subtle. I believe the Dayton film and foils worked just fine with a different brand of main capacitor, I no longer remember which. I do distinctly remember liking the AudioCap Thetas.

For what it is worth I didn't liked the sound of the Solen capacitors either until I started biasing them. I was kind of dubious of G.T.'s suggestion that I would like them charge-coupled, how does one spin gold from straw right? Needless to say, he was right. Go figure...

Come to think of it, he has never steered me wrong.... :hmm:
Thank you
I took your advice some time back and did several jobs with the Thetas and enjoyed the results. The reason I posted the question a while back (along with the PMs) and again today was that I had several "middle of the road" projects and the cap count was high. I just couldn't justify (afford) to bypass them all with AudioCaps, but I wanted to bypass them nonetheless.
Reviews by so called "professionals" for the Dayton film and foils was decent; several actually compared them as being not quite as good as the Thetas but very close.

I had used their standard types for mains several times with good results but had never combined them with their film and foils

I knew you had extensive experience experimenting with this and wanted your feedback before I soldered everything together (these were time intensive restorations and not new builds). Changing things out would not be desirable or very practical once put together; on one of them just finding the space to fit all the new film types in was a bitch (I was replacing non-polar electrolytics in old German boxes)

I finally made a decision and ordered a bag of the Daytons as well as their standard polypropylenes for the main values (I do like those and like them much better than the Solens). Two of the jobs are done and the results were very good (without having to squint), but neither qualify as good example of anything one would use for "critical listening". I will (can) say though that the results were a major improvement over what was originally installed (one was a pair of Klipsch Heresys)

Hate to say it, but I went ahead and put them together with the main values for my current JBL project, late production L100s (and re-stuffing their original cardboard tubes), the old style "Electro-Caps"

Labor intensive to say the least and I will soon know if going the cheap route was a mistake or not; there won't be any do overs with these as they are potted

The L100s will have Daytons for the main values as well

With such "iffy" candidates in the cap refresh queue that was why your feedback was important to me; in other words, would what you found objectionable even be a factor (detriment) in these not exactly the last word in resolution boxes (but I know, every little bit helps)

The Thetas for bypass would have nearly exceeded the costs for the total main value count; that was the rub

Glad to hear you say that it's like it always is; depends on what you're using them with and not simply a complete dismissal

Here's hoping I didn't just kick myself in the ass cheaping out!

4343
08-20-2015, 08:55 PM
...
Here's hoping I didn't just kick myself in the ass cheaping out!

BTDT.

The first attempt I made recapping my L110's (to get back sorta on topic?) was some generic Mylar caps from the local surplus house. Fortunately I had bought a second pair of N110's and was able to compare to stock. Even after a reasonable amount of time, there was no doubt that the stock caps were much better. Interestingly enough, they sound great when biased. Only problem is that I've bought all the large values they had...

4313B
08-20-2015, 08:56 PM
Glad to hear you say that it's like it always is; depends on what you're using them with and not simply a complete dismissalNo, they were "bad" in conjunction with some brand of main capacitor that I have since forgotten. I want to say that they worked just fine with the Dayton metalized polys but I can't remember for sure. I thought I posted what they worked fine with.

I had run into something similar years before using Solen main caps with Sprague bypass caps.

Wagner
08-21-2015, 06:51 AM
No, they were "bad" in conjunction with some brand of main capacitor that I have since forgotten. I want to say that they worked just fine with the Dayton metalized polys but I can't remember for sure. I thought I posted what they worked fine with.

I had run into something similar years before using Solen main caps with Sprague bypass caps.
Post #13 is what I stumbled across that got me going wanting to know the particulars:
http://www.audioheritage.org/vbulletin/showthread.php?664-Capacitors

4313B
08-21-2015, 08:54 AM
Ok, so the Dayton bypass caps worked fine with the stock JBL mylars then.