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Allen65
08-18-2007, 01:41 PM
Just purchased at set of JBL L100t's because in the past I've heard numerous JBL setups that sounded awesome. AFter reading numerous excellent reviews I couldn't resist. After hooking them up I was disappointed to hear a weak hollow sound, almost like an old PA speaker that's barely working, like all the sound comes out all of the speakers, not really separated or full.

At first I thought it was a lack of power to push them because I was only using a 70 watt per channel kenwood. I then bought a Denon receiver/amp that pushes a little over 100 per channel, and while it sounds very nice on my polks, the JBL still sounds horrid. Anybody have any ideas? No speakers are blown.

Sadly there is no jbl repair center anywhere near here, so I can't take them in to have them looked at. If any can give some ideas or solutions I would apprecaite it. There is no way a set of these JBL's should sound this bad. Oh and btw, I'm new to the forum:D

Thanks, Allen

BMWCCA
08-18-2007, 01:55 PM
You might want to start by posting a photo or two on this site. It's possible, given the propensity for speakers of that age to have deteriorated surrounds, that someone could have replaced the speakers with generic components. A shot of the front with the grilles off could at least help to confirm you're starting with the correct components. If the originals were re-surrounded you could have a wiring problem, or a bad crossover. From your description it sounds like a lot more than just a phasing issue.

hjames
08-18-2007, 02:03 PM
Did you get a chance to listen to them before you bought them, or was it a purchase off that "auction site"?
Best bet is to pop the grill off and have a look at the drivers. Also take some pictures and post them here.
I've got a pair of the smaller version, the L20Ts, and while the '20Ts lack a bit in bottom end (which expected as they are small speakers) the overall sound is quite good. I'd expect the 100Ts shouldn't suffer the same lack of bottom as the smaller (lower priced) L20Ts.

Assuming that both amps are good quality, I don't expect you'd hear much difference between 70w/ch and 100w/ch - you'd actually need to go beyond
150w/ch (double the power) to hear much difference in volume.


Just purchased at set of JBL L100t's because in the past I've heard numerous JBL setups that sounded awesome. AFter reading numerous excellent reviews I couldn't resist. After hooking them up I was disappointed to hear a weak hollow sound, almost like an old PA speaker that's barely working, like all the sound comes out all of the speakers, not really separated or full.
Oh and btw, I'm new to the forum:D

Thanks, Allen

JSF13
08-18-2007, 02:17 PM
Don't know your experience level but having owned L100T's, as well as 4311's, 4312's I can tell you the L100T's sound awfully good when functioning properly. Almost sounds like some of the drivers aren't working properly. Put your ear up to each one to make sure they are working, or better yet if you have a good old Radio Shack SPL meter put on some pink noise and measure the near-field outputs of each driver.As suggested put up some pics if you can.:hmm:

grumpy
08-18-2007, 03:45 PM
I agree with JSF13... funny, as I pulled out a pair this weekend to listen to.
A/B-ing them with Polks may not be the best way to evaluate, but it sure
would appear that there's something damaged based on your description.

If anything, I'd think "bass heavy" might be a normal opinion if they're not
set up well. In a ~10ft triangle listening arrangement, they image pretty well.

There are no crossover adjustments, although the crossover could be smoked. -grumpy

(BTW, large Perreaux amp is rarely lighting the bottom power indicator ~16w
and I wouldn't be comfortable listening at much higher levels... so I also agree
that having enough power is not your main issue to address)

Allen65
08-18-2007, 05:02 PM
I've had them set up strictly as the main speakers and had the same result. I'm not an audiophile expert but I had wondered if someone had replaced the crossovers before and wired them wrong myself. I bought them from Ebay, and it was guaranteed that they worked. The watts per channel isn't alot different but the denon is way better thaN the kenwood, much lower distortion, and just overall better. I plan on getting separate pre-power amp setups later but for now Im staying with the denon.

I have listened closely to each individual speaker, and each has sound, just sounds like it's hollow, empty, and maybe not separating. The surrounds look to be all intact as well. Unfortunately my scanner met a terrible death recently so I can't upload pictures atm. I thought of trying to find a wiring schematic for the crossovers to make sure they were wired right if they were replaced.

Like I said I know that brand is much better than I'm hearing. Upon receiving them I had to reattach the midrange insulating cone( not the technical term i'm sure) that had come loose during shipping causing the midrange to be unplugged, but that would only affect one speaker and they both sound that way. Is there anyway I can ID the speakers and crossovers to make sure they're right?

Allen65
08-18-2007, 05:09 PM
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230143838711&indexURL=0&photoDisplayType=2#ebayphotohosting

Thats the ebay pics from the auction, not very good for detail I'm afraid.

grumpy
08-18-2007, 05:18 PM
crossovers can be had from Harman (if this is indeed the problem):

http://www.harmanaudio.com/search_browse/partlist.asp?Parts=L100T&BrandId=JBL&MarketId=HOM&Language=ENG&Country=US&Region=USA

see also:

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L100t%20ts.pdf

(L100T on the right appears to have had it's 2214 "re-surrounded" ... rather poorly (glue showing)

Who knows what got knocked around on their way to you... happy troubleshooting.

Allen65
08-18-2007, 05:22 PM
I don't recall seeing any gaskets behind the woofers when I took them out, could this maybe be some sort of insulation issue? Judging by the pics from grumpy's link the speakers are the right ones.

grumpy
08-18-2007, 05:29 PM
gasket could be stuck to the woofer frame (or missing). in either case, this
would not cause the problem you are describing (small air leak or lack of
"insulation"). ... and yes, the drivers appear to be the correct units.

Allen65
08-18-2007, 05:44 PM
SO even though I don't know much in this field, I'm leaning towards my original assessment....either bad crossovers or crossovers being wired wrong. Chances would be better that they're wired wrong than both crossovers going out at once IMO. This is killing me lol, I drooled over the speakers forever , now that I have a pair I wanna get them lined out:D

johnaec
08-18-2007, 05:51 PM
I'd also check the crossover wiring. It looks like those woofers have been refoamed, which would mean they've been out of the cabinet and possibly re-hooked up wrong...

John

grumpy
08-18-2007, 06:31 PM
I'd also check the crossover wiring.:yes:

I'll make the wild assumption that the seller wasn't intending to screw anyone...
if the crossover wiring checks out, I'd bet on driver damage
from shipping (hoping not). Midrange cup (isolation) coming loose isn't
a particularly good sign.

Allen65
08-18-2007, 07:27 PM
They were very rough with them. I hear sound from each speaker though, is there a way to test the drivers that I can do?

JSF13
08-18-2007, 07:36 PM
I think the first thing you have to do if you've not already done so is remove the speakers and make sure the speakers are wired correctly ie positive/negative. After that run some pink noise and check to see if all the drivers are all roughly the same volume and sound like pink noise should.

grumpy
08-18-2007, 07:45 PM
If you have a way to send a test signal to the speakers, such as a test CD
or a computer with a sound card and a test tone program, then
you could at least verify that each driver has roughly similar loudness
within it's range of operation and doesn't sound distorted or scratchy.

I hesitate to suggest too much, as it's not hard to damage drivers when
they are out of the cabinet or used without a crossover. If you've verified
crossover connection, a shop might be your next best bet.

(thought about suggesting inter-station noise as a "pink noise" simulation, as
I see that JSF13 has now put forth... could compare this to what it sounds like
with your Polks... I really think sine-wave tones would make any issues more
obvious, but if that's all you've got, then there you go).

Allen65
08-18-2007, 11:58 PM
The crossovers in the speakers look nothing like what's in the diagrams, so gona try the jbl homesite and maybe i can find somethign there.

I have 3 computers and a cd player but no program for testing for the pink noise.

Zilch
08-19-2007, 12:34 AM
Are the wire colors correct going to the drivers, i.e., greens to the woofer, whites to the mid, and yellows to the tweeter?

Allen65
08-19-2007, 12:39 AM
I took the one woofer out to egt a look, and all wires seem correct, only thing I can see other than the cone surrounding the midrange being loose would be that the crossovers look different than in the schematics.

I've tried googling to find a picture of the correct crossover to see if it really is the right one, but other than the drawing grumpy linked me to I can't find a thing.

JSF13
08-19-2007, 07:34 AM
I took the one woofer out to egt a look, and all wires seem correct,

Allen, at the very least you have to check BOTH woofers and make sure they are wired up correctly and the same. If it were me at this stage I would check EVERY driver and make sure they're wired up correctly as per the diagram Grumpy referenced.

Allen65
08-19-2007, 11:14 AM
< If it were me at this stage I would check EVERY driver and make sure they're wired up correctly as per the diagram Grumpy referenced>




Yes I have them both out and they seem to be wired right. My only concern is the diagram looks nothing like the crossover I'm seeing inside. ANybody know of a link where I can see an actual picture of the correct crossover? I'd like to make sure I'm looking at the correct crossover inside the speaker. I know Grumpy's link is correct, my concern is that maybe they put a different crossover inside.

Allen65
08-19-2007, 04:37 PM
The tweeters on both speakers are not playing at all. According to the diagram the yellow/black wire should be on the left if looking at the back, however on the tweeters it is on the right, the fittings prevent hooking it the other way.

I tried just touching them the other way but nothing came out then either. The wire connections on the woofer are the type you just push the handle down and slide the wire in, but on the diagram it shows the same type as the tweeters. That ring a bell anyone?

Don C
08-19-2007, 04:45 PM
Your wires are set up that way on purpose, to prevent them from being hooked up wrong. You need to check the tweeters with an ohmmeter, to see if the voice coils are open. That seems likely now.

Allen65
08-19-2007, 04:52 PM
I was just wondering why on the diagram the ground wire was shown on the opposite side as on the speaker.

Titanium Dome
08-19-2007, 05:17 PM
I was just wondering why on the diagram the ground wire was shown on the opposite side as on the speaker.

Perhaps it's not the original tweeter, or maybe it's a later variant.
The L100T used the 035Ti and the L100T3 used the 035TiA. These nearly identical tweeters were different in some key ways, including the magnet and the connections. On the 035Ti, the yellow wire connects on the right; on the 035TiA the yellow wire connects on the left.

Verify which of these drivers you have, then verify DCR between 3.5 and 4.2 Ohms.

Allen65
08-19-2007, 06:28 PM
Even if it originally had the 035T! and now has the 035TIA it should still play something shouldn't it?

Titanium Dome
08-19-2007, 07:13 PM
Even if it originally had the 035T! and now has the 035TIA it should still play something shouldn't it?

Well, let's be sure you're looking at the right diagram.

Since you cannot provide pictures of anything, you'll need to verify things as you're asked. Otherwise, we're just talking in circles.

Let's start simple: what is the exact model number on the enclosure? Is it L100T or L100T3? Then, what are the model numbers on the drivers? Is the woofer 2214H or 2214H-1? Is the midrange definitely 104H-2? Is the tweeter 035Ti or 035TiA? What number is on the crossover: N100T or NL100T3?

Once we have these things cleared up, then better suggestions can come forward. :)

grumpy
08-19-2007, 07:19 PM
I believe the pictures early in the thread (ebay link?) showed L100T models.

I wouldn't worry about the crossovers not looking exactly like the diagram,
nor about the polarity on the tweeter (which should be 035Ti).

That the tweeters are likely smoked is a problem, and probably explains
the "bad" sound. L100T crossover pic attached...

-grumpy

JSF13
08-19-2007, 07:32 PM
Allen, I notice your ebay vendor, who advertised these as "in good working condition", has 5 negative feedbacks in the last 6 months. Perhaps it's time for another.:biting:

Titanium Dome
08-19-2007, 07:52 PM
I believe the pictures early in the thread (ebay link?) showed L100T models.

I wouldn't worry about the crossovers not looking exactly like the diagram,
nor about the polarity on the tweeter (which should be 035Ti).

That the tweeters are likely smoked is a problem, and probably explains
the "bad" sound. L100T crossover pic attached...

-grumpy

If there's a link in this thread, I sure don't see it. Where is it? Am I losing my sight?

grumpy
08-19-2007, 07:54 PM
#7

Allen65
08-19-2007, 08:02 PM
I stopped posting in the other forum so Grumpy doesn't pull his hair out:D

ANyway the case is definitely L100T

The tweeter is 035 TIA
Midrange is 1040h-2
Woofer is 2241h-1
crossover isnt for the L100T it is the L80T.

I couldn't find anything but the jbl part number didnt say n100t or N100t3 on it, but seeing the picture of the l80T they were exact matches.

grumpy
08-19-2007, 08:17 PM
Double check the resistor values... (white rectangles).
The L80T and L100T boards appear to be the same boards
with slightly different component values. I'm guessing (now) that
your crossovers are OK. :) and thanks for thinking of my hair...
there's blessed little of it on top any more.

035TIA vs 035TI isn't a show stopper (connectors are in a different
spot, but they're not grossly different ...) the differences were discussed
somewhere here awhile back...

grumpy
08-19-2007, 08:22 PM
http://www.audioheritage.org/vbulletin/showthread.php?t=4272&highlight=035Ti+035TiA

(search = compliments of TiDome)

Allen65
08-19-2007, 08:24 PM
Let me take the woofer back out:D Can the entire speaker be ordered? I checked that link for parts you ave me but only saw one for the midrange. Be back in a few.

grumpy
08-19-2007, 08:35 PM
Ebay or have them "re-domed" ... appears that the repair
kits (from JBL) are different in cost by about $30 each (035TI's being
more expensive)... perhaps someone here has a pair to sell you
(after you confirm they're blown). :dont-know

over $100 each appears to be -one- quoted shop price for TIA version

Allen65
08-19-2007, 08:40 PM
Here ya go Grumpy..

from right to left it reads as follows..
10w20 ~j
10w1 ~2j
10w2~4j
10w20~j
10w39~j

I replaced the little symbol they had with the tilda since I can't replicate it:D

grumpy
08-19-2007, 08:44 PM
:applaud: L100T crossovers they be.

On the schematic (N100T)
R3 20 ohms
R4 1.2 ohms
R2 2.4 ohms
R5 20 ohms
R1 39 ohms

Tweeters are next.

Allen65
08-19-2007, 08:46 PM
Tweeters are 035TIA.

grumpy
08-19-2007, 09:02 PM
As has been suggested, you will want to verify if the voice coil (fine wire
winding inside of the 035TIA) has acted like a fuse ...
and try to get some financial response from your Ebay seller.

a reading of a few ohms (not a dead short) and a small "click" sound
during the reading might indicate all is not lost. You did say you verified
the wires were connected to the 035TIA terminals... yes?

New 035TIA's (from jblpro vs. from Harman Audio) appear to list for $146/ea

Ebay is most often less (sometimes by quite a bit), but crap floats so caveat emptor.

Allen65
08-19-2007, 09:39 PM
I verified that they're connected. Guess I'm at a stand still until until i can borrow my dads meter. Was just odd to me that both would go bad at same time.

Zilch
08-19-2007, 10:01 PM
Not at all:

http://www.jblpro.com/pub/technote/lowpower.pdf

Allen65
08-19-2007, 10:30 PM
well my other amp was 70 watts a channel which isn't strong but should have been more than enough to not blow anything, and it was like that from day 1 when I got it. The guy I got it from used an adcom amp for it that had 100 watts per channel also so that should have been fine, but of course I have no clue how he had it set up or anything. So when I order the new speakers would yuou go with the 035 TI or the TIA's?

JBLRaiser
08-20-2007, 05:19 AM
you want to go the Ebay route, None showing up for auction presently.

http://search-completed.ebay.com/search/search.dll?sofocus=so&sbrftog=1&catref=C6&from=R10&satitle=035ti&sacat=14998%26catref%3DC6&sargn=-1%26saslc%3D2&sadis=200&fpos=31808&sabfmts=1&saobfmts=insif&fis=2&ftrt=1&ftrv=1&saprclo=&saprchi=&fsop=2&fsoo=2

grumpy
08-20-2007, 06:52 AM
So when I order the new speakers would yuou go with the 035 TI or the TIA's?If you get them new, you may not have a choice. Looking at crossover for the later
L100T3, which came with the 035TiA, I see about four parts that have changed
related to the mid/tweet crossover and balance... I'd -guess- that this change would
make more difference than the tweeter itself. There are probably threads here
(L100T vs L100t3) that go into this in grisly detail. If you want a suggestion (someone
already made it , I think), look for two of the same (from whatever source you're comfortable
with) and don't worry about it.

-grumpy

BMWCCA
08-20-2007, 08:11 AM
I don't own anything with an 035Ti but it seems to me I recall seeing a quite frequent discussion of solder joint failures in the diaphragm leads. Is the 035Ti able to be disassembled easily enough to check this?

I just found a link that discusses just this problem with a repair suggestion for using a later diaphragm from Lancing Heritage's own GordonW:
http://www.audiokarma.org/forums/showthread.php?t=63121

The original poster actually fixed his problem by repairing the wire. There was also a suggestion about using the 052Ti (like my 4412As), but if a simple repair will work, that would be nice for you.

Good luck.

Allen65
08-20-2007, 11:05 AM
They no longer sell anything for the L100t3. Looks like I have to go the ebay route and pray...
So if I go the 035 TIA route I need to also make sure I have the matching l100t3 crossover and not the l100T or does it matter? Thanks guys.

grumpy
08-20-2007, 12:08 PM
If you want new:
you might try jblpro to see if they have any (that's where the $146/ea came from ...
their price list from July... the pro line used this tweeter in Studio Monitors also: 035TiA)
http://www.jblproservice.com/parts.html

I would not expect you would need to change crossovers, unless you prefer the
sound of a L100t3 to a L100T ... you might consider this a update later, after all is
working (the change seeming to be the crossover voicing vs. an audible or
measurable tweeter difference).

I wouldn't discount the idea of getting the units you have repaired professionally (could
save you some $$$ over new).

Then there's ebay... someone's selling a new pair, it would appear:
http://cgi.ebay.com/2-JBL-035-TIA-tweeter_W0QQitemZ260149550422QQihZ016QQcategoryZ47 092QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

and a used set:
http://cgi.ebay.com/JBL-035TIA-HF-Drivers-Pulled-From-L7_W0QQitemZ280144155631QQihZ018QQcategoryZ3276QQs sPageNameZWDVWQQrdZ1QQcmdZViewItem

Allen65
08-20-2007, 12:30 PM
I did a search there just awhile ago for the o35tia and found nothing lol. Thanks again. It's starting to become an obsession with me to get this thing working :banghead:

grumpy
08-20-2007, 01:04 PM
FWIW.

If the 035TiA's you have test out bad (open circuit) and you get new or repaired units,
you might want to check across C7 (3uF) to make sure it hasn't shorted (however
unlikely that may be)... with amp and -all- of the drivers disconnected, this should read a
bit over 40 ohms; if it's closer to zero, or over 60 ohms (blown L4), it would be worth
checking further before hooking up your new tweeters.

Smoked tweets does seem the most likely culprit.

Allen65
08-21-2007, 11:07 AM
If the tweets AND crossover both test bad I'll just buy another set form ebay and then send these off to have them repaired for backups. I'm gona try for that new set of tweets you linked me to and hopefully not have to give up my left arm to get them:D

Allen65
08-26-2007, 06:37 PM
Tested those tweets and they read a big zero so yeah they're both bad. xovers seem fine

grumpy
08-27-2007, 06:48 AM
Hope you can find a nice pair of replacements. -grumpy

Allen65
08-27-2007, 01:22 PM
Thanks, got that new set you gave me the link to. Had to pay 200 for a new set but that's still cheaper than ordering them.

grumpy
08-27-2007, 01:38 PM
Had a chance to hook them up? (starting at low volumes and with any bass control/knob
turned down ... make sure you're only getting high frequency info through, and that the
drivers are working) -grumpy

Allen65
08-27-2007, 02:14 PM
They won't be shipped until thursday. Other than just putting my ear to the tweet how can i tell if only highs are coming out? The tweets on both speakers were exactly the same so I assume he just blew them.

grumpy
08-27-2007, 03:05 PM
Other than just putting my ear to the tweet how can i tell if only highs are coming out?
Reasonable question.
Pretty much put your ear to the tweeter. A CD with test tones would help as well.

The crossover is at 4.5KHz, so other than cymbal crashes, triangles, exaggerated vocal
sibliants, jangling keys, etc... everything else should be significantly reduced in volume.

DavidF
08-27-2007, 03:10 PM
They won't be shipped until thursday. Other than just putting my ear to the tweet how can i tell if only highs are coming out? The tweets on both speakers were exactly the same so I assume he just blew them.

Best way I know IS to put my ear right in front of the driver.

Grumpy walked you through this in a pretty good way. Kudos, Grumpy.

DavidF

EDIT:

Also, best if you have ALL systems powered off when you plug or unplug, ANYTHING. Let the amp rest power off for a minute. Removing equipment interconnects with power up is about the best way I know to try to blow both tweeters at once.

Zilch
08-27-2007, 03:18 PM
Hold a roll of toilet paper or paper towels to your ear and in front of the tweeter.

This is ZilchLab trade secret testing methodology, so keep it to yourself.... :p

Allen65
08-28-2007, 03:07 AM
Appreciate the help. Now just have to wait for the new tweets to arrive:D

rek50
08-28-2007, 07:22 AM
"Roll of TP" :applaud:...............OR, a short length of "Heater Hose", (Automotive/New/Clean). The "Extra" length allows for positioning by "Eye", to preserve the protective screen contour..........

Allen65
09-06-2007, 02:18 AM
And wow what a difference they make. They now sound like I expected them to. I DID find a short in one of the speakers however, but it seems to be at the connection, so plan on putting some new connectors on this weekend. Thanks again guys I appreciate the help.

grumpy
09-06-2007, 06:45 AM
:applaud: