4343 vs 4430 experience

[Robh3606]

Hello Jon

"Thankfully, JBL has never produced a horn with comical visual aesthetics."

What!! Your kiddin right?!

Your just so used to your Dolly Partons, Butt cheeks you don't see it anymore.

Rob

[Don McRitchie]

Thankfully, JBL has never produced a horn with comical visual aesthetics.

Damn straight.

(Jon wispers in Don's ear)

Never mind.

[Roddyama]

Originally posted by Earl K
Hi Ian / Bo

I was wondering if Rodd was considering an MTM setup with those 4, le10s he has ?

<>EarlK

Hi Earl,

I had considered it, but the main thing I wanted to accomplish is to try and match the dispersion pattern of the L91 slant plates with the dual LE10As near the xover point of (in my case) ~1200Hz.

At first I was going to build a baffle for my old AR 2a boxes with the LE10A flanges butted together. But than I got lazy when I came upon an old pair of Lancer 77's. So I just built a second baffle for the 77's (now ~1-1/2" thick) with the same driver spacing. (Of course the 77's had 1-driver and 1-PR)

WRT the HL91's (and later the 2312's), the main fix is to very firmly wrap the outside of the horn with heavy rubber. Before I obtained some 3/8" neoprene, I used a rubber door mat I bought from Home Depot for $5. Then I used muffler clamps to hold the rubber tight to the horn (you can use wire ties if you can get them tight enough).

The baffle is the same thickness as the horns flange like it came from JBL. I cover the entire baffle (at least 12" wide) with 1/4" thick closed cell foam (not the stuff they use in humidifiers) except around the horn opening. There, I take the foam right to the edge of the horn mouth. The foam is glued with contact cement everywhere.

For the lens, I cut a bunch of 1/2" wide strips. I take a small screwdriver and push the same foam rubber into the spaces between the fins doubling over the strips so they are ~1/4" into the back of the lens. Again, I do this everywhere except at the mouth of the horn.

The result was great. The horns were smooth and detailed with no noticable peaking (never measured), yet always had that live sound to them that we all love so much. BTW, you must be very picky about the amp you use to drive the horns. The best bang for the buck amp I've found are the old NAD's.

[Ian Mackenzie]

For the lens, I cut a bunch of 1/2" wide strips. I take a small screwdriver and push the same foam rubber into the spaces between the fins doubling over the strips so they are ~1/4" into the back of the lens. Again, I do this everywhere except at the mouth of the horn.

You mean like this..for example

Ian

[Roddyama]

Hi Ian,

Yep, you've got it.

[Earl K]

Thanks Rodd for that.

Much appreciated. I happen to love le10s - have 6 or 7 - & could use more.

I've lots of extra parts here and may do up a MTM with le10s & a 2410/2307/11 combo in the center. Just thinking out loud. Throat Reflections are measureable anamolies with AC impedance - so I may go looking for "reasons" behind you mods success. I say "May" because ADD does set in on these sonic quests.

regards <>Earl K

[Roddyama]

Originally posted by Roddyama
Hi Earl,

I had considered it, but the main thing I wanted to accomplish is to try and match the dispersion pattern of the L91 slant plates with the dual LE10As near the xover point of (in my case) ~1200Hz.

Sorry Earl,

I must revise this a little. The dispersion was actually a an added benefit, but the main reason for that particular configuration.. The main reason I went to dual LE10A's was that I was always dissatisfied with the weak transient attack of the 10A's. I mean for years I felt they were a poor match for the horns on top. When I finally did go to duals, they were slightly better, but still lack the punch you get from the sharp rap of the snare drum.

What I found was all the time it wasn't the speakers, but the x-over. I tri-amp with a Heathkit x-over crossing to the 10's at ~80Hz @ 6db/oct. One day the hi-pass section of the x-over died. I played with it and got it working, but it didn't sound right. Than I finally put in a PLLXO in place of the hi-pass section of the Heathkit and the 10A's came to life like I never hear them before. The transient attack was just plain awesome. The 4 - 10A's all hitting at the same time to produce the image of the drummer with his arms flailling.

[4313B]

"The main reason I went to dual LE10A's was that I was always dissatisfied with the weak transient attack of the 10A's."

"Than I finally put in a PLLXO in place of the hi-pass section of the Heathkit and the 10A's came to life like I never hear them before. The transient attack was just plain awesome."

Wow!
I've never heard "weak transient attack" used to describe an LE10 before. I'm glad you got that worked out.

[Earl K]

The transient attack was just plain awesome. The 4 - 10A's all hitting at the same time to produce the image of the drummer with his arms flailling.

Yeh - now that makes more sense . I also have 2123 and 2012, 10 inchers . They all have different timbral balances that are quite intriguing when it comes to mixing and matching with other components. Right now I use le14s paired with le10s in a quasi MTM setup. These 2 speakers are very complimentary to each other. They produce prodigous whallop at low volumes - & viscerally move a lot of air even at the mid 80 dbs - where I listen .

I really love what JBL does with Aquaplas. I'd love to hear an aquaplassed cone working in the deep gap of the 2012. I have an extra le10 cone/coil needing a resurround but I refuse to sacrifice a virtually new 2012 to such a one-off type experiment .

regards ,>Earl K

[Roddyama]

Originally posted by Earl K
I have an extra le10 cone/coil needing a resurround but I refuse to sacrifice a virtually new 2012 to such a one-off type experiment .

regards ,>Earl K

I have a pair LE10A surround replacement kits complete with 4 large black VC covers and glue. Do you want them? I've reside myself to the fact that I'll never use them.

[Earl K]

Hi Rodd

Sure. PM me so we can work out the details. Or email me direct at KZL Audio . Since I'm leaving Toronto very shortly, I don't want to move on this till the new year.

regards <> Earl K

[Guido]

Hi Earl!
Hi Rodd!

I'm seriously interested in the results

DOOO that test.

[Ian Mackenzie]

Hi John,

How is your JBL Wall of Sound going?

Just been reading these threads.

My we had some fun with that.

http://www.audioheritage.org/vbullet...ght=nebel+4343
http://www.audioheritage.org/vbullet...ght=nebel+4343
http://www.audioheritage.org/vbullet...ght=nebel+4343

Even Don as I recall visited at one stage.

Where are you at with all thing now?

[John Nebel]

Hi John,
Where are you at with all thing now?

Hi Ian,

I never use the 4343s, however, inertia has kept them in place. Like Herodotus when commenting on something close to religion, "that is all I have to say about the matter".

The Hummingbirds haven't returned yet, but any day now. There was a nest in the back last spring which Don saw when he visited. The bird would attack anyone walking by.

John

[Ian Mackenzie]

Hmm,

I thought that might be the case.

As a consequence I think I will arrange a 4430 for all my soft classical listening. Black is black as they say but the gravity is such the 4345's are staying where they are.

On birds our Magpies are like that.

They say being shat on is good luck!