JBL L100T's

[Allen65]

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

Thanks, Allen

[BMWCCA]

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]

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

Thanks, Allen

[JSF13]

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.

[grumpy]

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]

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]

http://cgi.ebay.com/ws/eBayISAPI.dll...ayphotohosting

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

[grumpy]

crossovers can be had from Harman (if this is indeed the problem):

http://www.harmanaudio.com/search_br...=US&Region=USA

see also:

http://manuals.harman.com/JBL/HOM/Te...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]

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]

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]

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

[johnaec]

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]

I'd also check the crossover wiring.

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]

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]

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.