4343 vs 4430 experience [Archive] - Lansing Heritage Forums

John Nebel

11-26-2003, 02:11 PM

Since last weekend, I've set up an a/b comparison between pairs of 4343s and 4340s.

The amplifiers are virtually the same - 200 watt Mac on the 4343s vs 250 for the 4430.

Both systems are biamplified with JBL 5235 crossovers with the appropriate cards.

The 4343s were modified to the extent I swapped in 2122s and 2235s while the original drivers were being reconed. I should test with the original drivers.

The 4430s are physically on the outside of the 4343s, ie. they have two speaker widths' greater separation. I should switch these around and test again.

The 4430s sound better to the several people who have participated in this informal test. The stereo image was more stable and the speakers sounded less like loudspeakers. The frequency response and dynamic range were roughly the same although the the 4430 sound more full. A pink noise measurement showed a flatter curve for the 4430s.

The source material for the test for one musician-listener was Monteverdi choral music and Schubert's 9th symphony, both at concert level.

This was not the result I had expected as I thought the 4-way system would outperform the 2-way system.

Running the 4343s biamplified and the 4430s on their internal crossovers may tip the scale the other way but that test wasn't as lengthy.

Has anyone else run a similar comparison?

John Nebel

Mr. Widget

11-26-2003, 02:28 PM

I have never done that A/B, but your outcome doesn't actually surprise me. You definitely should try them again with switched positions.

A wider range of source material and perhaps a wider range of listeners might give you a slightly different outcome. One thing I've noticed over the years, is that a simple smile from a participant in a comparison like this can affect the outcome. That said, I think your results are probably pretty accurate.

My experience with stock 43XXs has been one of disappointing imaging and a peaky midrange. With my slight to significant mods I have been able to satisfy my pursuit with my 4355s.

boputnam

11-26-2003, 02:39 PM

Hey, John... :wave:

Real glad you posted this. Thought-provoking... :hmm:

I recall a one Giskard commenting that (I think...) G.T. felt two-way systems were flatter and easier to time-align / EQ than were more complex systems. And, there certainly are complexities inherant in a four-way, boy-howdy. I don't know if he was referring to the 4430 per se, but interesting comment, nonetheless. Did you do any fiddling with the L-pad settings, which on the 4430 are quite influential on the performance characteristics of the bi-radial?

If you're inclined to re-position the cabinets, I'd suggest:

4430 / 4343 (aquarium) 4430 / 4343

and/or, versa-visa. That way, neither pair is at either the extreme or minimum spacing.

Mr. Widget

11-26-2003, 02:57 PM

You've got an aquarium between your speakers! That can't be too good for imaging. The more tightly controlled 4430s certainly will perform better than the 4343s in a room with less than ideal reflective surfaces.

I agree with Bo about that alternative speaker placement to help even the playing field.

boputnam

11-26-2003, 03:06 PM

Originally posted by Mr. Widget
You've got an aquarium between your speakers! That can't be too good for imaging. Ha! :rotfl: I was just foollin' around. I don't recall there being anything between where the 4343's were when I was there. I only used it in that post as a place-keeper... ;)

Mr. Widget

11-26-2003, 03:12 PM

Still room acoustics could play a role in the outcome of such a comparison. In my case with my finally being happy with my current set up, it may be the room that is improving the imaging as much as any of my mods. It is one of the most acoustically dead rooms that I have heard 43XXs in.

boputnam

11-26-2003, 03:29 PM

:rotfl:

mikebake

11-26-2003, 03:35 PM

Robert G, no longer seen in this neck of the woods, seemed fairly adamant about the overall superiority of the 4430 two way vs. the bigger 3-4 ways. He said he had listened to about all of them fairly extensively.
Anyway, the simplicity of dealing with various issues by utilizing a two-way does have some merit.

John Nebel

11-27-2003, 02:07 PM

Hi Bo,

After cabinet shuffling to 4440-4443-4440-4443, the 4430s still sound better. I could live with either pair, which is fortunate in this case.

All the L-pads are on 0.

The 4430 sound is more of a space than the 4343's directed beam. One can loose track of the source more easily with the 4430.

John

leif

11-27-2003, 02:40 PM

Anyone that has tested the 4430 vs 4435?
Is the 4435 just as good (or better) as you all say the 4430 is?
There is a pair for sale over here for about 2000 us dollars. That is a lot of money, and it is far far far to pick them up. Is it worth it?

I have a large living room, and plenty space for them.

Leif

MikeM

11-27-2003, 04:40 PM

I A/B ed the 4430 against the L300. 4430 had much more bass output. smoother less irritating horn sound But I think the L300 was overall better balanced. This was years ago and with old crown Dc300s so anything is possible. Really not a bad sounding little speaker was the L150 with the cloth dome tweeters. Ineffecient as hell but dam good bass comparred with the big brothers even outperfomed them Sometimes. Tweeters start to go at 650 a side......:smthsail:

Tom Loizeaux

11-27-2003, 08:40 PM

The ability of the HF horn on the 4430 to cover 100 x 100 degrees is great if you walk around your listening room or have quests that sit in a variety of seats, but for delivering stereo to a listening sweet spot, I doubt the 4430 horns offer any advantage when compared to the 4343s full spectrum.

Tom

slxrti

11-28-2003, 02:01 AM

I own a pair of 4430's I used then for my front channels. I listen mainly to pop, in two channel stereo.

It's amazing how they can lay transparent a poor recording. High sensitivity speakers have the ability to bring forth the dynamics lost in the recording process. Friends marvel at there ability to render music with uncanny realism.
Be cautious of bright sounding amps or a room that lacks curtains or has hard reflective surfaces. The wide sound
Field causes 1st and 2nd order reflections to become a large constituent of what is heard.

The 4430’s are not sweet or soft-spoken like many High price stereophile loudspeaker. They play with gusto, heart and most of all emotion!!!

Do they have any weakness. For HT they need a sub. The 2235 combined with a passive tuned to below 25
Hz can do some damage, and with eq. can get down right scary (next project). The performance approaches
a closed box with, but with the efficient of a port design.
At earsplitting loudness the 1" can become screechy. Yet in 95% of the instances the loud speaker is not loud enough!!! It becomes apparent if I on the TV or notice that phone had rung with a message remaining.

Can they be enhanced? Sure. I would consider a three way. Using a 2118 or 2123 as a mid base. Cross over at
200 and 1kh- 2khz. I would not use the a configuration similar to the L300, because it's very directional and the substantial horn distortion..

The 4430 had a sale cycle of almost 20 years which is amazing considering that most speaker are updated every few years. I don’t believe any other speaker in the JBL line can lay claim to that. It a shame that this monitor does not get the justice it deserves. I guess that the reason they are still reasonable priced.

I compared the 136a, LE15 and 2235. The 2235 is better in every way possible. The le85 couple with a HL92 or
91 through the music me (spot light effect) and just plain lacked refinement of modern horn designs ( Specially when crossed over at 800 hz). The slotted tweeter crossed over at 7khz can down right hurt, so I prefer the baby cheeks.

Since I'm on suject of horns, the short horn for the 375 is about the same as the HL92, the wooden horn makes it sound silly. How do I know ???? because I owned most if not all of the above.

Not to sound righteous, the above is my opinion and other can disagree with my findings.

take care slxrti

Ian Mackenzie

11-28-2003, 04:00 AM

Slxrti,

I like your comments and those earlier,

In a previous post (I don't recall) I did a comparision of a system using the JBL 2245, 2122, 2425/2344, and then compared to a 4 way using the JBL 2245, 2122, 2307/2308 +2305.

As horn carving master Mr Widget aptly remarks, the room acoustic plays a key role in final result as I found in my assessment.

However, I consider the distribution patterns of the 2344 and 2307/2308 can either be used to advantage or disadvantage as the case maybe. The 2344's prefer to be toed in and placement is better apart than too close with absolute symmetry.

The 2307/2308 is a totally different beast and likes only a smidgen of toe in, the 15 degree angle as per the earlier manuals is about right, the boxes are better closer than far apart.

I think its called the Hass effect...not sure to be exact.

Regardless, the 2344 appears a more holograhic expanse while the image of the 2307/2308 + 2405 array appears more from behind the drivers.

In terms of tonality, open a bottle of CaB Sav abd start tasting.

I owned the 2344 for about 2 years and loved them to death, but after hearing a diy 4343 I fell on my own sword.

In a nut shell, with an amp that isn't grinding metal in the top end the 2307/08 + slot is ruthlessly accurate and cleaner with better transient definition. On the otherhand the 2344 is more livable in terms of playable recordings.

Ian

slxrti

11-28-2003, 05:37 PM

I still have a pair of alnico slots, on certain types of music they can sound wonderful with the 2307 horn. But after about 15 minutes of listening to varies types of music I have to turn it off. I felt the same about the L300's. It did not matter where they were place. I new where they were. With the 4430's if I darken the room and relaxed the musician would appear. I never achieve that effect with the slots /2307 combo.

The slot's are brighter than the baby cheeks but at the cost of
resolution. A snare drum sounded blurred, yet the baby cheeks did not have the same effect. Even a novice listener noticed this.

The above are my observation and other opinion are appreciated

slxrti

Mr. Widget

11-28-2003, 05:52 PM

Originally posted by slxrti
I still have a pair of alnico slots, on certain types of music they can sound wonderful with the 2307 horn. But after about 15 minutes of listening to varies types of music I have to turn it off. I felt the same about the L300's. It did not matter where they were place. I new where they were. With the 4430's if I darken the room and relaxed the musician would appear. I never achieve that effect with the slots /2307 combo.

The slot's are brighter than the baby cheeks but at the cost of
resolution. A snare drum sounded blurred, yet the baby cheeks did not have the same effect. Even a novice listener noticed this.

The above are my observation and other opinion are appreciated

slxrti

I know exactly what you mean! In general I have had the exact same personal experience. Don't blame the slot though. When used properly it can sound exceptionally good. It needs a steep crossover slope and I prefer it at or above 10KHz.

For years I thought of the 077/2405 as an implement of aural torture, but after learning how to tame it, I discovered they can be enjoyed for hours on end.

Mr. Widget

11-28-2003, 06:29 PM

Originally posted by Giskard
Hey! Me too! :bouncy:
I placed a 1k ohm resistor in series with it and presto! Instant love!

That will certainly tame them!:D :D

Ian Mackenzie

11-28-2003, 10:51 PM

Here we go again, another rant and I haven't even got my 4345 going yet......

Ian:(

Ian Mackenzie

11-28-2003, 11:53 PM

That okay,

My don't we start the vintage 43xx club with Don's new project underway

Actually a mini baby cheek moulded into the upper cheek as a super tweeter could be cool

Maybe Jon and help with a prototype..muhahahah.

I get the impression GT was impressed with Jons horns.

Ian:cool:

slxrti

11-29-2003, 01:05 AM

I don't have an issue with the 43xx series. I try to share what I learned with others and hopefully others will share their insight with me. With that said, I entertain all comment
good or bad about either series. (It just so happens that I have a pair of 4311 in the closet).

If the 43xx series flip’s your switch do what make you happy and share the result us!!!:)

slxrti

IDF

11-29-2003, 03:51 AM

Since last weekend, I've set up an a/b comparison between pairs of 4343s and 4340s.

The amplifiers are virtually the same - 200 watt Mac on the 4343s vs 250 for the 4430.

Both systems are biamplified with JBL 5235 crossovers with the appropriate cards.

------------------------------------------------------------------------------

Hi John,

Could you please tell us what were the L-Pad setting for both models during this test?

Thank you.

Phil

John Nebel

11-29-2003, 07:22 AM

Phil,

The L-pads were all set on zero. In the case of the 4343s, that was the setting which gave +/- 3db response to 1/3 octave pink noise measured close to the listening position.

The 4430s are recent interlopers and have not been measured all that carefully.

John

4313B

11-29-2003, 08:26 AM

At one point I owned the 4343B and the 4430 concurrently. I still own the 4430. Back in the 70's and very early 80's the 43xx were simply too cool to resist.

If I still owned my 4343B's they would be running the 4344/4345 filter and if I went out and sought a stock 43xx today I would most likely choose the 4345.

If I were to put any extra time and effort into one of the old 4-way systems I would most likely tri-amp and use the highest quality passive components between the exponential horn/CD and the slot loaded ring radiator. If I'm not mistaken, Ian bought Hovlands for his filters and I am very anxious to see what he thinks of them in this application! :yes:

One can ignore my personal slights on the slot loaded ring radiators and exponential horns. (Sorry! :D) It's no secret that I am no longer a fan of exponential horns. That's a personal choice formed after years of listening to them. As for the slot loaded ring radiator, it first became available around 1970. It is still sold today as a 100% viable UHF solution. That is quite an illustrious run for a transducer :)

Robh3606

11-29-2003, 08:38 AM

Thanks for posting this! I have been setting up to try a 4344 like set-up. I have 2344 and think they are great horns. I wanted to do a similar comparison to see which I liked best. I have never heard a pair of 4344 so I really don't know what to expect. All the set-ups I have had have been hybrids of one form or another never the "real deal" so I wanted to give the 4430/4344 a go to see what they were like.

Rob:)

Ian Mackenzie

11-29-2003, 02:57 PM

My plan is to get them to testing stage in about 3 weeks (weekends).

All I can say is the jig test fitup was quite promising, and nothing like my recollection of the 4333.

Ian:smthsail:

Ralf

12-01-2003, 03:23 PM

If one day anybody will messure out a 4430 cabinet and post the results here, we (Guido and me) will run a real subjective a/b test...

Is anybody here, who knows what I mean?

If you want results bevor end of century, you have to hurry up... :-)

4313B

12-01-2003, 03:44 PM

Originally posted by Ralf
Is anybody here, who knows what I mean?I think I know what you mean. You're expiration date is sometime before the new century so you would like some answers beforehand? I've already done extensive A/B of the 4430 and the 4343 so I'm not really in any kind of hurry. I'll try to get some numbers to you guys in the next day or so. Are you wanting to build the 4430's 100% stock?

Guido

12-01-2003, 04:01 PM

:thmbsup:

Let the measuring start!

Fortunately one is willing to support us crazy two germans:nutz: :nutz:

Looking forward to your numbers. Thanks Giskard

Oh, not to forget: 99,5% stock! The bracing we can manage ourself.

Ralf

12-01-2003, 04:03 PM

Originally posted by Giskard
Are you wanting to build the 4430's 100% stock?

100%, yes. The network is ready. New reconed 2235 are waiting for jump in new home...the wood arrived last week...the buzz is running...trap...trap...trap...waiting for the measurements....

Tom Loizeaux

12-04-2003, 09:17 PM

Following Giskard's suggestions, I just finished bypassing the crossovers in my last pair of studio monitors. The 4343s got AudioCaps while the 4333Bs and the 4320s got Daytons. I've been switching these speakers around each week or so - and I must say they ALL sound great! I listened to several of my favorite CDs yesterday (Fourplay, Lee Ritenour, Larry Carlton, Bob James and Sarah McLachlan) on the 4320s, since I had just added bypass caps to the 3106 crossovers. I was very pleased with the clarity of these speakers. Then I switched over to the 4333Bs. I slid them around and repatched the wires from my bi-amp stack. Wow, these were great too! They seemed to have a little more boom in the low end then the 4320s, but I always tweak the crossover balance when I change speakers. As I've said before, the 4343s seem to go a little deeper then these others and the mids are slightly more full and smoother then the 3-ways.
I don't seem to have any problem listening to these 2307 or 2312 horns with the slant plates and really like the 2405s.
Anyway, add me to the list of people who are content with the 3 and 4-way vintage JBL studio monitors.

Tom

Guido

12-05-2003, 05:27 AM

Let me move a little bit off the red line of this thread.
As you may know, Ralf and me are working on a pair of 4430. Of course they are not finished yet. As soon as we have them up and running we will do extensive testing. Believe me:yes:

In the meantime I did an A/B Test with my new DIY 4425 / 4343. OK, they have not really a chance but....

Bass:
Unbelievable how deep this 4425 goes:spchless: It is not only the spec sheet that tells us that both, 4425 and 4343 are tuned to 34 Hz. It's real.

Mid Bass, Mid
Here there is a clear advantage for the 4343 what was to expect. More clear and ?punchy?

MidHigh, High
Amazing, Insane:spchless: This 2342 Horn is definately better in imaging. It produces the artist inside the room. Wow

Ultra high
No doubt! There is a lack of UHF with the 2342/2416 combination. But it is not so obvious and always present that I could say it is really downgrading this little 4425.

Finally I have to say that I can't wait to have the 4430 for testing:dancin:

4313B

12-05-2003, 08:15 AM

Only an A/B of a stock 4343 or 4343B and a stock 4430 would be valid. ;)

Heck, my modified 4430's sound better than my stock 4430's! :)

I think you are using significantly better components in your all your filters aren't you Guido? Plus a 2012H in place of a 2121H?

Guido

12-05-2003, 09:39 AM

Originally posted by Giskard

Heck, my modified 4430's sound better than my stock 4430's! :)

I think you are using significantly better components in your all your filters aren't you Guido? Plus a 2012H in place of a 2121H?

Hi Giskard,

what did you modify with your 4430? Or is it a secret ;)

In my newer filters I use only high high quality components. But I do not use too low DCR inductors as JBL also does not.

My 4343 network is stock. OK nearly stock. I modified the mid section with additional 20 uF as Earl K once recommended and I bypassed the slot. No other bypasses as I didn't like the sound of the 2420 when bypassed.

Finally the 2012H. Yes I still don't have a 2121. But with the x-over mod the 2012H is amazing.

Robh3606

12-05-2003, 10:12 AM

Hello Guido

"This 2342 Horn is definately better in imaging. It produces the artist inside the room. Wow"

Expect the same from the 2344. Real nice imaging qualities. I have a pair of 2342 too but have not compared the two. Very different looking horns through the mouth and slot. I was always curious if they do indeed sound different.

Rob:)

Ian Mackenzie

12-05-2003, 12:43 PM

Okay, I don't agree chaps,

It depends on your notion of imaging,

A holograph yes is nice, but the same holograph regardless..are you kidding.

And where are the dynamics.......I mean hello.

Read On............

My direct comparisons suggested the 2344 had a nice sweet spot and this required absolute symmetry of the speakers and depending on the toe in, a varying degree of imaging.

Finally, what did it was I could never make my mind up on whether to toe em in slightly or at 45 degree direct with my ears.....the problem was I could never hear enough direct over reflect sound Man.

Unless you have absorbent tiles all around the room, I fail to see how you can control this..(a studio is a different matter)

Besides, I can't think of many musical instruments that produce a constant 100 x 100 polar response, nor the human voice...its bullshit, pigs arse really Man.

On the other hand, the 4343-54 has controlled dispersion and the direct sound verus reverberant sound is more obvious and controllable. (the bells on Dark Side of the Moon,,,wow)

This is why the imaging is perceived deeper in in the sound stage and expands outward when you unleash your big amps and you get the sensation of a big band walking through your listening room .

The effect of loudness being a real live sensation...the hallmark of JBL.

I could never achieve this with the 2344 without the reverberant field swamping all the direct energy.

Finally, the 4343-45 has more extension and dynamics.

The issues of the 2405 are more a matter for correct set-up and quality capacitors.

Recent tests rendered the transition from the 2307/08 to the 2405 unperceivable.

Ian
:rockon1: :shock: :wave: :band: :dancin:

Robh3606

12-05-2003, 01:23 PM

"Besides, I can't think of many musical instruments that produce a constant 100 x 100 polar response, nor the human voice...its bullshit, pigs arse really Man. "

Please don't be shy. Tell us how you really feel on this.

:rotfl: :rotfl: :rotfl: :rotfl: :rotfl: :rotfl: :rotfl: :rotfl: :rotfl:

Rob:cheers:

Ian Mackenzie

12-05-2003, 02:13 PM

What,

When I blow........my horn its .......well you know.

:bomb:

Ian

Earl K

12-05-2003, 02:43 PM

:smthsail: :scoot: :cheers: :wave:

I love them all - that's why, they all get to live in my living room with the horses, cats & dogs >? EarlK :D

But really, in the days of the Ludites before the internal combustion engine, life was mostly an exponential experience.
Now with many forms of alternative realities - life is one large barage of CD spray. Yea, back to the future .
- 2¢ philosophy for the masses.

JonFairhurst

12-05-2003, 03:44 PM

I had a pair of 2307s for years. I had the 2308s too, before they fell apart. The lenses just don't handle the road or small children well.

The fact is, I never liked them. Without the lenses they were too beamy. With the lenses they had too much phase smear. In either case I found them harsh and resonant. Like Giskard I have learned not to like exponential horns. (When you put your ear up to them, you can hear the ocean!) But, coupled with a good compression driver, they sure can dish out the dynamics!

I've found that I like fast flare horns much better than the long throats. A pair of K2 S9800s would be fine, thanks!

Ian's right about the 2344s giving more reverberant energy than the 2307/8 or many other HF solutions. But, the fact is, I like it. I find it more balanced with the LFs, which go omni-directional anyway. I use mine in a home studio environment, and I like that I get a balanced spectrum whether I'm sitting at the PC, standing with a guitar or over at the MIDI keyboard.

So, where did my wretched 2307s end up? At Ian's house! It's great to know that they are now in good use, providing great enjoyment. Rock on, Ian!

Disclaimer: I've never heard the 2344s or 2307s in a fully stock configuration. Maybe with the right amp and x-overs in the right room, I would have loved the 07/08 combo. (Actually, I did hear a pair of stock 4430s many times, but the room was horrid. It was for video post at Grass Valley Group, and was about 20 feet wide and six feet deep with a low ceiling and glass on the back wall. Yuk!)

Earl K

12-05-2003, 03:58 PM

Hi Jon

I've found that I like fast flare horns much better than the long throats. A pair of K2 S9800s would be fine, thanks!

Yea, I agree. I usually like a fast flare on whatever sort of horn, compared to a long throated ??? - even CD type . I would really like to hear a H9800 someday . You know - it has some interesting curves builtin into it - including - by the looks of it - some exponential curves loading the vertical axis . :D

<> Earl K:)

4313B

12-05-2003, 05:04 PM

Originally posted by JonFairhurst
(When you put your ear up to them, you can hear the ocean!)Wow! I heard a fat lady singing with the ocean in the background.

Mr. Widget

12-05-2003, 05:08 PM

Originally posted by Giskard
Wow! I heard a fat lady singing with the ocean in the background.

Yeah, but the fat lady always seems to have a nasal problem.:D :D :D

Robh3606

12-05-2003, 08:07 PM

Hello Ian

Just messing with ya:D I will be trying the same combo you have going now so I will see then which I like better. I don't have enough recent time on the 2307/2308 slot combo to really say for sure what the deal is. You are right though the 2344 does bounce lots of energy into the room. It seem's to work in mine. Not sure how the other will fare.

Rob:)

4313B

12-05-2003, 08:21 PM

Yes, I wholeheartedly agree that everyone should build both systems and give them a spin. I think Mike Caldwell has some 2307's and 2308's for sale so let's help him get rid of them :)

subwoof

12-05-2003, 08:55 PM

I am building a pair of baffle boards to experiment with for the 4343's in the shop. The 2420/2307/2308 combo is being replaced with a 2373 ( MR series horn ) with a 2426J driver. This eliminates the "smear" and "kid" issue with the HF and allows a normal grill to be used on these to reduce overall footprint depth ( SAF issue ). The baffle area they occupy is almost the same.

Of course the 2405 will be retained to sterilize teenage bats that wander too close. The components will be aligned in a true L/R mirror image ( vertical cabinet use ) for slightly wider image ( similar to the 4345 ) in a small room....

I will post a picture of this when I thaw out the shop and finish them...:)

On the 2344's - I had a stock pair of 4430's in my living room for years. The imaging was pretty good considering the placement dictated by the other half...unfortunately the space behind the horn flare was a favorite hiding place for the TV remote...:)

I found that the 2421A drivers HF was lacking - I installed the later version 2426J and boosted the level a bit.

sub

JonFairhurst

12-05-2003, 09:02 PM

>> "On the 2344's - I had a stock pair in my living room for years. The imaging was pretty good considering the placement dictated by the other half... "

What? She had you turn the lobes around to face the wall, did she?

I hear that John Ashcroft has a pair of 4430s, but he covered them with $10,000 worth of JBL blue grill cloth. (Ba dump.)

subwoof

12-05-2003, 09:09 PM

Well lets just say that black sabbath's IRON MAN dusted one end of the high back couch pretty good...:)

Dah...dah... dah duhn duhn...

Ian Mackenzie

12-05-2003, 09:55 PM

It would be interesting to line up the 4343, the 4430 and the DMS1 in the same room.

From the white paper it appears a next generation 4430 but heard little about it other wise.

The horn driver was superior and a different type of horn also.

By the has anyone played with the 275ND?

My gut feel is that the silica shower effect you "Dam Yankees" Err complainin about is related to resonance damping at certain frequencies along the inner surface of the horn.

My brothers 4343 have the original Ali bottle tops, they definately tingle on certain program material and my Ti bottle tops sound more mellow.

Old bottle tops should be pitched out every few years, probably half the issue here if truth be known......Bo what is your comment having replaced yours?

The effect is more noticable in the narrow straight exponentials I agree.

Tractrix king Bruce Edgar has studied the anomalies very closely and I recall ages ago reading an article about vibrations traveling down the horn sides in a very thin air layer causing a fine jaggered edge super imposed on the overall frequency response only seen under high magnification.

See the continuing posts and a revealing link to an interview with Bruce Edgar.

Ian

JonFairhurst

12-06-2003, 01:54 AM

> "vibrations traveling down the horn sides in a very thin air layer"

Interesting. I know that with Formula One cars that they "discovered" the ground effect in 1978. They found that they'd get a certain amount of downforce with a given wing, but when the wing got close to the ground the force increased greatly with respect to drag.

From memory the Lotus engineers found this in the wind tunnel when they fashioned the side radiators into a kind of a wing shape. One of the suspension supports broke, the car lowered, and the downforce readings went nuts.

Before long, all the teams were using huge underbody wings surrounded by sliding skirts to maximize the suction cup effect. The drivers could corner on rails, but if you lost suction all hell broke loose. It didn't take long before the skirts were banned and minimum ground heights were enforced.

To make a long story short, weird things happen at the boundary between surfaces and air. These days wind-tunnels even have "rolling roads", since the fixed floors just didn't behave like a road being traversed at 180 mph.

Then to make things even stranger, we're dealing with dynamics (frequencies) rather than statics. It's not quite quantum mechanics, but it's not as intuitive as static physics either. Welcome to the imaginary plane of phase.

No doubt. Horns are as much an art as a science.

Ian Mackenzie

12-06-2003, 03:44 AM

Jon,

Your response is quite thought provoking.

Here is the link to the Edgar interview where he discusses the wisdom of modern day horn design.

http://www.positive-feedback.com/Issue4/edgarinterview.htm

Some key points:

With exponential horns, theory predicts that the wave form going down the horn is plane or flat, but the wave front has to drag along the horn walls.

The issue of concern is the wave front exiting the mouth of the horn, causing a bulge that is essentially a discontinuity. This gives rise to recflections which travel back to the throat and set up a quarter-wavelength resonance condition.

The curve nature of the wavefronts that minimise these reflections is the Tractrix curve.

Ian

:smthsail:

Ian Mackenzie

12-06-2003, 04:01 AM

Here is a recent picture of Bruce Edgar with his new Titan horn design. Note the curved wave fronts.

You may recall in a previous post the rant we had over the 2307 sea shell effect and experiments by a diy friend who has tweaked his JBL exponential horns with application of thin foam pads around the circumference of the horn mouth and under the slant plate lens.

Perhaps this is at least a partial remedy to the above reflections?

Ian

Robh3606

12-06-2003, 01:39 PM

Dr. Edgars tractrixs are very nice sounding indeed. Those speakers were a very nice treat at the 2003 MAF hosted by Mike B. Spent a good amount of time listening to them.

Rob :)

Hofmannhp

12-11-2003, 08:19 AM

hello Leif,

I exactly made this test with the 4430 and the 4435 and I think that its easy to explain:
The only diff is the deep bass which is about +6dB with the 4435 under 80 Hz.
I think the reason is only that in the area under 100 Hz the second 2243 works parallel , and this in the bigger box.
short: the low bass of the 4435 is fantastic.

Hanspeter

jandregg

12-11-2003, 09:21 AM

I have looked high and low but cannot find the documentation. I recieved a note from jbl with some 91 horns saying to not smooth the rough paint inside the expo horn as it was that way deliberatly to improve the sound.

Earl K

12-11-2003, 10:51 AM

That's really interesting!

When was this ?

<> Earl K

subwoof

12-11-2003, 11:01 AM

OK - look at this picture. It is a jbl / urei horn used in the coaxial 12' 809C studio monitor.

the horn *sides* go from smooth, to rough foam to closed cell foam ( rounded ) on the horn edge.

This is designed to correct reflections and control the pattern....

sub

jandregg

12-11-2003, 07:37 PM

Earl

That was in 1975.

boputnam

12-11-2003, 08:54 PM

Originally posted by subwoof
...the horn *sides* go from smooth, to rough foam to closed cell foam ( rounded ) on the horn edge.

This is designed to correct reflections and control the pattern.... Hey, Widget - what you know about all this? :confused:

Robh3606

12-11-2003, 09:06 PM

Urei Horns

The foam edges are also there to help control diffraction effects of the horn and the woofer about 3 inches behind it. The last version of the larger horn on the 15's had slots cut into the horns close to the foam pads inside. They crossover around 1k.

Rob:)

Mr. Widget

12-11-2003, 09:10 PM

In the case of the Urei, I believe the foam has to do with the fact the horn is mounted in the woofer and it is to reduce their interaction (read to prevent the two sources from mucking each other up too much) It probably helped dampen the ringing as well. Always a problem with thin walled horns especially if they aren't terminated into a massive baffle. As for texture on the Urei, I am not sure I could speculate.

As for the JBL exponential mentioned by Jandregg, my guess is they would try anything to make those sound better... oh no, am I starting another one of those threads..

Actually in reading the interview with Dr. Edgar that Ian posted on one of these threads, Dr. Edgar mentions reflections traveling down the sides of exponential horns... might have something to do with that, or it might have been lore. I think there were folks at the factory that were smokin' a bit too much back in the '70's. Heck that's when they came up with your favorite speaker the L- what was the number?:D :D

Mr. Widget

12-11-2003, 09:12 PM

Yeah, like Rob said.

Or I prefer the scientific term. Muck.

Robh3606

12-12-2003, 08:27 AM

Urei horn from the C versions

Ian Mackenzie

12-12-2003, 08:36 AM

Looks like a good case for wave disscontinuity given the short horn length.....

Ian

Earl K

12-12-2003, 09:48 AM

Hi

- Thanks Jan / SubWoof. I had never before seen a connection made for the use of a rough texture coating within the 2307 ( to give a bit of resistive loss/damping to control throat reflections ) .

As for the JBL exponential mentioned by Jandregg, my guess is they would try anything to make those sound better... oh no, am I starting another one of those threads..

Actually in reading the interview with Dr. Edgar that Ian posted on one of these threads, Dr. Edgar mentions reflections traveling down the sides of exponential horns... might have something to do with that, or it might have been lore. I think there were folks at the factory that were smokin' a bit too much back in the '70's. Heck that's when they came up with your favorite speaker the L- what was the number?

- Most of what's quoted above can be given a lot of illumination & insight by reading Harry F. Olson "Acoustical Engineering". His studies of for a group of exponentials ( & other types ) clearly show the resultant acoustic effects derived between relationship of horn length vs mouth opening. The chapter called "Acoustical Elements" display graphs showing the measurable " throat acoustical impedance" characteristics for different types of horns including conicals (or straight sided ) . The studies are with round mouthed horns. Once a person sees the graphs and relates them to the 2307/2312 round-mouthed, exponential family - one will understand whats' behind the comments of hearing the "ocean" when the horn is used to capture sound as a hearing aid. Not nearly as well understood is how JBL moved to sidestep the issue by crossing over above the obvious anamolies or maybe more importantly "averaging-down" the impedance of the anamolies ( with a lot of resistive loss ), derived mostly from their most sophisticated crossover designs.

Re; on the Urei foam & slots;

An article in db Magazine , August 1981 written by Dean Austin ( of United Recording Corp. ) really underscores all the reasons these bits came into being. The topical area is called "Therapy For SoundWave Trauma" . Great pics of a 2.3 kHz Tone-Burst , before and after the foam buffer/and other mods have been added. The extreme amplitude trauma to the horns' lower response ( around flare cutoff ) is also shown in a overall Response Graph.

- Too bad I don't have a scanner.

- All this really underscores the need for thoughtful termination for all types of circuits .

Ian Mac; your friends foamed termination of 2307/2308 combos will find some support from all of the above mentioned references .

<> Earl K :)

Ian Mackenzie

12-12-2003, 10:11 AM

I may invite Rodd to comment further.

I think it would help flesh out the issue for us JBL er's

Ian

Earl K

12-12-2003, 10:25 AM

Ian;

I did quite la ot of experimenting to modify the pattern of a 2308. This was done by inserting thin strips of acoustical transparent material in between the flat plates ( in certain areas ). The idea was to create different pressure or velocity changes/points within the lense itself. I found a lot could be accomplished- but - ADD overcame me before I could arrive at usable findings.

<> Earl K

boputnam

12-12-2003, 10:30 AM

Originally posted by Earl K
...ADD...? Acoustical Deficit Disorder? You talkin' about me...?

Ian Mackenzie

12-12-2003, 10:53 AM

Acoustic disfunctional disorder ...no he ain't refering to you Bo

Earl,

I have sent an email to Rodd for some insights.

Rodd is an authority on these tweaks and has taken ownership of some new horns I understand......the larger of the slant plate horns and the Tad driver

Bo, why don't you put a 2308 in front of your L100's , would that make them 43xx current......muhahahahah...the pot is already black.

Ian:o

Earl K

12-12-2003, 11:21 AM

Hi Ian / Bo

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

<>EarlK:)

Tom Loizeaux

12-12-2003, 02:37 PM

After reading and thinking about points made in this thread about horns, flare rates, disturbed and reflected waves, etc., I added a large piece of felt to the front panels of my 4343s (don't worry, they're very removeable). I put them directly behind the slant plates, running from one velcro strip to the other. My hope was that they would tame some of the HF reflection off the back of the slant plates.
Did it help? I don't know! They might sound ever-so-slighty smoother. I wound up turning the HF amp up just a taste.
They still sound GREAT, so I guess I didn't create a problem!

BTW, the insides of my 2307 horns are quite smooth. Is that a bad thing?

Tom

boputnam

12-12-2003, 03:06 PM

Originally posted by Tom Loizeaux
BTW, the insides of my 2307 horns are quite smooth. Is that a bad thing? We all suffer with that, Tom. Wondering Aloud...? Earl's post made me want to try a lightly sand-blasted surface, but then again, I'm really not up for altering anything on my 43xx large formats.

Originally posted by Earl K
one will understand whats' behind the comments of hearing the "ocean" when the horn is used to capture sound as a hearing aid. Well, I can't know about all that, but I do know that if you hold a rock up to your (good...) ear, you can hear the desert... :rotfl:

Mr. Widget

12-12-2003, 03:19 PM

Every H91 and 2307 I have owned (all 70's vintage) was smoothish on the inside. I say smoothish because due to flaws in the casting there were random scratches, bumps, and divots here and there and I am quite sure they were not put there intentionally. That is why I used the word "lore" in my previous post.

I certainly wouldn't worry about it. Whether you call it the ocean or desert it is still has an unnatural sound to my "tin" ears.

Don McRitchie

12-12-2003, 03:27 PM

Originally posted by Robh3606
Dr. Edgars tractrixs are very nice sounding indeed. Those speakers were a very nice treat at the 2003 MAF hosted by Mike B. Spent a good amount of time listening to them.

Rob :)

I agree. The Titan's were my choice for "best sound" at MAF by a wide margin. However, I have yet to warm up to the visual aesthetics. In fact, I have a hard time not snickering whenever I see them. It just looks too much like a cartoon character or that baseball mascot with the air horn for a nose

JonFairhurst

12-12-2003, 04:12 PM

>> "I agree. The Titan's were my choice for "best sound" at MAF by a wide margin. However, I have yet to warm up to the visual aesthetics."

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

Alex Lancaster

12-12-2003, 04:30 PM

And, what can You tell us about the cabaret speaker that had the horn actually polished?

I had some 2312´s cast and sandpapered with a die grinder, could not really hear a difference.

Alex.

Robh3606

12-12-2003, 04:36 PM

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:D

Don McRitchie

12-12-2003, 04:38 PM

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

Damn straight.

(Jon wispers in Don's ear)

Never mind.

Roddyama

12-12-2003, 06:08 PM

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

12-12-2003, 06:49 PM

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

12-12-2003, 07:01 PM

Hi Ian,

Yep, you've got it.

Earl K

12-12-2003, 07:38 PM

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

12-12-2003, 07:43 PM

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

12-12-2003, 07:53 PM

"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

12-12-2003, 08:08 PM

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