JBL L Series (1990s)

[CHagen7]

Actually, the CL-505 came after the rest of the line. Since they were designed in ’90, home theater was still just getting off the ground, so the center was not part of the original market plan. It was added near the end, after the L-5 was done.
It was slated to be a turnkey project from an external manufacturer. They sourced the transducers and made the cabinet, copying the L-series grille treatment. I may have had something to do with the crossover, but do not recall. It worked all right, but not using the same components made marketing decide to have the tweeter marked with H R D – High Rigidity Dome. I don’t think very many of these sold.
L-series kind of took off because the narrow width made it fairly nice for setting alongside of a rear-projection tv, but it sort of fell into this as I don’t think that was a design consideration of the industrial designer.

And, don't worry - I read the whole L-7 intro, and I'm good with it. Just the first few lines had me wondering "What the ?????"

(Side note: Design order was L-1, then L-3, then L-7, then L-5).

[rww1951]

Chris, welcome to the forum and I’m glad I was sitting down! I am the proud owner of L100s, L1s, L5s, L7s, and a CL505. Thought I’d better ask you a couple questions before you flameout. I drive the L7s (my favorite) with a couple of Carver TFM amplifiers and they sound AWESOME, I admire your designs everyday. It’s the first in my life I’ve had speakers and an amp that I can crank up to the pain threshold with no distortion. My question involves placement of the L7s. I know you’re not going to want to hear this but I am forced to have an equipment cabinet placed between the speakers. I live in a log home and have no other option (will post pics in a couple of weeks). Any suggestions on placement when faced with my limits. Should I reverse them and fire the woofers to the outside? Thanks Roger

[johnaec]

I love my L3's! What I find unusual is that it appears all the cone drivers, (with the possible exception of the 12" LF), are only used in these models, and no other series.

John

[bigstereo]

A little history - I started at Rogersound Labs in 1985, and designed a few including the wildly popular (for them) RSL 2600. Then I went to JBL in 1988, and started with the L100T3 series.

Sir, it is with great honor that I have the opportunity to say to you,
Thank-you for for your work on the L100t3. These are my favorite speakers of any that I've owned thus far.

RJ

[johnaec]

He goes by the code name "Giskard"...

Nope! Greg's posted here a number of times as gtimbers: http://audioheritage.org/vbulletin/member.php?u=2523 Greg and Giskard do know each other, though...

John

[CHagen7]

Hey, no problems on the questions. Actually I gave a lot of the placement diction to marketing for the manual, although I can’t say as I wrote it. And they did a heckuva lot purtier pictures, too!
But it’s true what it says: You can put the woofers to the outside, but it’s not as good as them firing in. Largely because if you’re firing them to the outside, there’s a mass between them that I didn’t voice with (usually called "TV"). Then you start getting corner enhancement of the 12" which unbalances the acoustic crossover to the 8". So it’s BEST not to, but if you have to point them out, I always figured 95% of an L-7 was STILL better than about 98% of the speakers out there, so it’s okay to do.
As it is, my L-7’s have a big ol’ Pioneer between them now. But I space them away, toe them in and point the woofers at the tv, and they sound great. (ok….rest of system: Syn 3 hor. Ctr, 2 x Syn 3 sub, and 2 x Citation 7.3 surr………..and yes, it’s easy to do human stress research upon my neighbor using the volume control). Oh – running mine with PS Audio 100 Delta, and everything else on a Citation 5.1.

I also did the L100T3, but was carefully watched by Greg through the project (since it was my first there). Afterwards, he basically kicked me in the rear and said "You’re on your own from here – you don’t need my help." GREAT guy. You guys with LX’es? Guilty. HP? Uh huh.
But I also did MR, P, and…………shudder…………….EPI. Yep, sometimes the straws are all nice and shiny bright, and beautiful, but other times the straw you draw is filthy, dripping with goo, and’s been you don’t know where.

As I mentioned before, no they didn’t show up many other places, but I DID manage to use the 6-1/2" woofer in Synthesis 3.

[Zilch]

Hi, Chris.

There's an L-R filter in Citation 7.4.

What's that about?

Also, what's different with 2214H-1 vs. 2214H?

[CHagen7]

L-R filter? Do you own one and you took it apart? You guys are GOOD!!! Well, it’s very simple really:
As we all know and love, the JBL woofers tend to have more energy in their motors than most other speakers. This does two things: electro-dynamically damps the bottom end as well as produces more output at higher frequencies. And so it’s very common to have a JBL woofer that climbs through its frequency band. (However, the L-7-series components actually were level, to mimic the competing transducers…) Now the 7.4 is a THX sub. And they want level performance out to above 300 Hz so it interacts with the subwoofer crossover correctly. If it climbs, it won’t do this and will be rejected (and the 7.4 was). So I put a parallel inductor and resistor in series with the woofer. The inductor shorts the resistor out at low frequencies, but as the woofer starts to edge out of the THX window, the inductor’s impedance is such that the resistor is coming into play to knock the woofer level down. It actually doesn’t do anything in the THX subwoofer bandwidth. I didn’t like playing with a resistor in series with the driver, but when I was done and had measured it to see where it kicked in, had listened to it, and compared it to what the inductor/capacitor version would likely be (it wanted to go 3rd order). I went for the simple yet elegant and cost-effective solution.
Note that Syn 3 did not need this, as the woofer was facing off to the side, and so measuring in front you didn’t see the rise so much.

You almost had me with that other question. But memory cells refired – the H was a brushed frame face (the forward facing lip just outside the screw-holes) whereas the H-1 was all black. The H-1 was used in the T3 L series, but prior to that it had used the H. I liked the H-1 better – didn’t cut your fingers as much. Not that I won’t bleed for my craft (I frequently do), but just carrying a woofer from here to there to do it?

[Zilch]

L-R filter? Do you own one and you took it apart?

Well, it's what some of us do around here -- figure stuff out and make new stuff:

http://audioheritage.org/vbulletin/s...5162#post55162

I found the filter hidden behind the insulation during the course of using 7.4 to measure all of the LE14 variants:

http://audioheritage.org/vbulletin/s...5722#post55722

We figured it out, but never knew the rationale for it. Ultimately, I scored a second one:

http://audioheritage.org/vbulletin/s...0441#post60441

H-1s are back in them now; they're still being used for, uhmmm, "research."

http://audioheritage.org/vbulletin/s...4&postcount=24

Thank you for your responses and insights!

[clmrt]

Nope! Greg's posted here a number of times as gtimbers: http://audioheritage.org/vbulletin/member.php?u=2523 Greg and Giskard do know each other, though...

John

Yeah, I know, I just had to though.

[hjames]

Yeah, I know, I just had to though.

Ahhh - you're the playful one, now aren't ya!

You really had Strum going, too! he he he

[clmrt]

About the L5,

"...but the president of JBL Consumer decided to tie it in to the 4-way L-7 by making it an 8" 4-way. When said and done though, it works, the drivers blended nicely (even with the uphill climb)..."

Can you elaborate on what you mean by "uphill climb", and what detriment was avoided in spite of?

[00Robin]

Chris, welcome to the forum and I’m glad I was sitting down! I am the proud owner of L100s, L1s, L5s, L7s, and a CL505. Thought I’d better ask you a couple questions before you flameout. I drive the L7s (my favorite) with a couple of Carver TFM amplifiers and they sound AWESOME, I admire your designs everyday. It’s the first in my life I’ve had speakers and an amp that I can crank up to the pain threshold with no distortion. My question involves placement of the L7s. I know you’re not going to want to hear this but I am forced to have an equipment cabinet placed between the speakers. I live in a log home and have no other option (will post pics in a couple of weeks). Any suggestions on placement when faced with my limits. Should I reverse them and fire the woofers to the outside? Thanks Roger

Roger,the best my big VOTT's ever sounded was in my log home with a vaulted ceiling. It seemed as though the sound was so good every hair stood on end. I'm no help as to the cabinet between them,but I will envy you every time you turn your system on in a log home. No matter how loud I dared to send them,the sound only got better and better. I'm all tingly just with those precious memories. Wood and sound go together like...like.. well,they just go well together. Maybe thats why REAL concert halls were built that way huh?

[Titanium Dome]

Chris, thanks for all the insight.

I have a couple of inquiries. First, please elaborate, if you will, on he LE120H-1 driver, used in the L7, the Citation 5.4, and the Fosgate Audionics CSS220. Second, I'd be grateful to know the intended use(s) of the jumper on the L7s LF network.

[doucanoe]

Doucanoe has that issue of SR...

Bingo!
Stereo Review - June 1989 pages 75-81

There you are Chris, doing your thing up on the roof of the JBL facility. Very interesting article titled " The Making of an American Speaker".

Nice outfit by the way. You could pull that out of the closet and it would play as well today as it did then. Everything that goes around, comes around as they say. I still have a few of those myself.

RC