JBL L Series (1990s)

[BMWCCA]

IMHO, it's time for these musings to occupy their own thread. It's no longer a discussion of an under-appreciated series of JBLs and the current turn has begun to detract from the original.

I'm not saying there's no place here at LH for a personal platform or a journey of enlightenment, au contraire! It just seems this bent has taken a well-respected, established thread that deserves to be archived for posterity based on its historic value into a whole other realm best addressed and confined to its own narrower perspective.


Might I suggest the subject line: "Pug's Journey Toward L7 Nirvana"?

[Regis]

Ken,

Thank you for your thoughts on Engineering and Recording parameters, it was an intriguing read, indeed. I have to agree with BMWCCA and JBL Addict. It is time to lay this thread to rest (or at least the speaker design, dynamics and inherent properties of the L Series).

[Titanium Dome]

IMHO, it's time for these musings to occupy their own thread. It's no longer a discussion of an under-appreciated series of JBLs and the current turn has begun to detract from the original.

I'm not saying there's no place here at LH for a personal platform or a journey of enlightenment, au contraire! It just seems this bent has taken a well-respected, established thread that deserves to be archived for posterity based on its historic value into a whole other realm best addressed and confined to its own narrower perspective.


Might I suggest the subject line: "Pug's Journey Toward L7 Nirvana"?

Yes, this thread has gone far from its intended path.

[ken.pugmire]

I agree Its off the path. This thread should be educational about the speaker as a model not about engineering and modification. Im going to start a performance specific thread as there are many things id like to learn myself.

Out...

P.S. I hope I have added value to this thread and not detracted from the archival nature.

[gferrell]

Hey guys,
I am expecting a turntable tomorrow, I can't wait. I have some albums from 30+ years ago I want to hear on my L7's. I hope it sounds as good as I think it will. If not I will fix it. I may need some help though if you guys are willing!

[JBLAddict]

[QUOTE=gferrell;285580]Hey guys,
I am expecting a turntable tomorrow, I can't wait. I have some albums from 30+ years ago I want to hear on my L7's. I hope it sounds as good as I think it will. If not I will fix it. I may need some help though if you guys are willing![/QUOTE

been very close to pulling that trigger myself, starting to long for that old school analog sound, pls convey your impressions on the L7

[jbl-ahhh]

I just picked up a pair of L5's for cheap because they need surrounds and one 708G wasn't making any noise. I didn't have time to take it out and check it with a meter so I took a chance and got them as-is. They are really nice but it turn's out the 708G is an open circuit. I'm kind of surprised given that both tweeters are fine.

Just wondering if any other L lovers have had a driver go open circuit and if they were able to repair it.

[jbl-ahhh]

In a day or so I'll take off the dust cap and hopefully find a disconnected coil wire that I can reattach, but if not, any other ideas?

[gferrell]

been very close to pulling that trigger myself, starting to long for that old school analog sound, pls convey your impressions on the L7[/quote]


I found this, http://www.dual-reference.com/tables/CS741Q.htm, turntable at a flea market for $12.00. A little work and now its working perfect. I was surprised at the sound on my LP's. I am not use to the pops and crackles every now and then. The percussion from drums are great, strings are nice and symbols stand out. A warm sound that has taken a little getting use to. I did not realize the volume has to go much higher to achieve the same level. I guess the pre voltage is lower coming from the turntable. I need to find some more clean LP's now. Most of mine from the 70's to early 80's are in poor shape. But the ones that are clean sound fantastic. Definitely a different sound. The more you listen the more the sound becomes familiar, that is if your old enough to remember what they sounded like way back when. I feel the L series are a good match for the old LP's. Fun to listen to.

[gferrell]

In a day or so I'll take off the dust cap and hopefully find a disconnected coil wire that I can reattach, but if not, any other ideas?

They show up on fleabay every now and then.

[gferrell]

Regarding LP music I just wanted to add that speaker placement and listening position is more critical than digital sources with my L7's. The sweet spot sounds really great. I have not tried listening to the surround L5's at the same time. I may try that but it seems inappropriate.

[gferrell]

I just picked up a pair of L5's for cheap because they need surrounds and one 708G wasn't making any noise. I didn't have time to take it out and check it with a meter so I took a chance and got them as-is. They are really nice but it turn's out the 708G is an open circuit. I'm kind of surprised given that both tweeters are fine.

Just wondering if any other L lovers have had a driver go open circuit and if they were able to repair it.

L5's needing surrounds surprises me. Could you describe the condition of the drivers? Or better yet pictures would be nice.

[BJL]

I've seen some L series drivers with brittle surrounds but they had obvious signs of sun exposure (cones were badly faded). Otherwise, I never came across any that needed refoaming. Perhaps they were damaged and refoamed previously.

JBL-ahhhh, maybe you should post some pics?

jbl-ahhh did post some pics in this thread, one of which I've GIMP'ed:



The woofers in my L5's have similar cracks developing all the way around.
Not shot yet, but probably not performing as specified either.

[jbl-ahhh]

Here are pics from one of the 708G woofers. (Still can't quite bring myself to use the term "low frequency driver" instead of woofer ) They look the same as the original surrounds on the L-3's I repaired. It's that kind of pseudo-rubber-shiny-looking material that apparently doesn't hold up for beans compared to ordinary foam surrounds!

Haven't gotten around to removing the dust cap from the bad 708G to see if there are signs of damage -- kind of avoiding potential bad news I guess. I'll probably do it tonight. I'll post pics if I find anything of interest.

[jbl-ahhh]

Hey, I just noticed that the 6 1/2" mid-bass driver in the L-5's seems to be sealed (acoustic suspension) not ported. The woofer is ported but the mid-bass has a box around it inside the cabinet and when I depress the cone then release, it takes almost 2 seconds for the cone to return to the neutral position. Same goes for the 5" midrange. An interesting design. Are any other JBL speakers built this way?