upgrading the 4430 monitors

[Ian Mackenzie]

Yeah,

Sounds like we got a live one....

Sorta information overload sometimes Monte, it doesn't have to be done by tomorrow morning you know...just joking.Muhuuhuh

Okay, so you wanna build a better mouse trap. Sounds like you are a perfectionist. If you plan to do some recordings the 4343 will knock you over.

With the 4430, just to be sure I would play with the high frequency level control on the adjust the HF extension, the 15 inch woofer may be masking the highs also.

It would appear the 4430's have some value in the market place, so thats you call. So you are running with plan B pending how quickly you can sell the 4430's. Are there monetary contraints???

With some assistance there is no faking a 4343 to make it, several members have this model, get the slide rule and tape measures ready boys!! Somewhere I have a cross sectional drawing of the 4343 in a book by John Eargle, I scan it for you.

By the way 4343s some times come up on Ebay and there was a 4345 (18 inch woofers) in the forum classifieds in mint (to die for) condition, Iwould see if this is still for sale (or sold).

As a project the procurement of the parts for the 4343B is the first step, and this may take some time depending on availability as some of these parts are obsolete JBL lines. So you could use the woofer and the horn driver until you sell the 4430's.

Check out this link http://www.jblproservice.com/support_info.htm
There you will find details of the 4343 parts and the crossover network, and http://www.jblpro.com/pages/obsolete.htm for the pdf on the 4343B, the horn is the 2307, there is only one 2405 per box.

If you want to move reasonably quickly, the 2235 and 2426 with the 2344 on hand will give you a leg in on the project, the baffle for the mid and highs on the 4343's is removeable, so you can make and bake your system as parts come your way.

Checkout these for parts:
http://www.jamminjersey.com/speakers.htm, and Vintage audio sales, http://www.vintageaudiosales.com/, there is also the tent sale at JBL, there are some 2123's still there but they are 16 ohms although this probably does not matter, you can still order 2123s new from JBL as I understand it.

That is probably enough for now, Just to make you drool a bit....here they are

Ian

[Ian Mackenzie]

Here is the drawing, sorry about the quality, Ah just for training purposes (Copyright issues.)

[MikeM]

well I have the big brother 4435. I have yet to really find an electronic crossover that does these speakers well. Always get a hump or somesort of irregularity in the crossover range on 6/12/18 db curves. Sometimes here keeping them out of line is better as far as better transparency in the front end. Anyway 4435 owners try this trick, On the 4435 the second 15 is brought in at 100hz or so at a slowww rolloff and then is attenuated about 6 bd. i have a spooky little switch on the crossover that i can bypass the resistors on the 100 hz sub increasing the lowend. Not for purist sound but only for the live stuff. Works well

[MikeM]

Originally posted by Giskard
Spooky little switches can be fun

Have you already tried the 5234A/5235 with the 4430/4435 cards?

Yes I have. Had the cards custom done with both types 12 and 18 db.Also tryed Mx-4, vfx-2a, sumo delilah,Marchand board type.
Right now im single amping with quite good results. Maybe will try again later!

[MikeM]

Originally posted by Giskard
Wow, I don't see Sumo Delilah's around at all. Do you still have one? Do you have the Samson too?

Interesting that you should have trouble with the 5234A/5235 and the 4435 because technically it shouldn't work right out of the box and you should end up with a bump (has to be EQ'd out). The card was designed for the 4430 and the 2234H is sufficiently "peaky" at 1 kHz to cause a problem when using the 4430 card in the 5234A/5235. In other words, JBL should have come out with a 4435 card and they didn't. If you used a 5234A you should also install bypass caps like JBL did in the 5235.

I wouldnt go as far as saying i was having trouble with it its a nice unit. I used to drive myself nuts with adjusting reajusting so i said the heck with it and went single amp. think I noticed was a Blurr in imaging ect. I used the 5233/4 with my 4350's before mono block lowend and audioresearch tube highend with staggering results. resolution was fantastic. Wish i had more room here. Thanks for the info!

[Monte]

"Sounds like we got a live one…" … you funny guy …

Seriously, I do appreciate the enthusiasm and willingness by you and everyone else in this group.

Now I've slept on it. The 4343b would deliver a really big upgrade in refinement over the 4430. I certainly don't need bigger, badder, lower or louder. Refinement and accuracy is the key.

Why go all the way to the 4343b? Well, if I'm going to need to build a new box, anyway, might as well. Also, the 4430's will keep value intact. The 4343 drivers—not cheap—but certainly not THAT expensive when you consider what you're getting. I can afford to get them while holding the 4430. Buying someone's factory 4343's, though, just might be too pricey. There aren't many choices there. Also, when I bought the 4430, I was lucky that the location was a one-day driveable distance--probably not so lucky with harder-to-find 4343's.

Upon reflection, I think that I can conceptualize why the 4430's, as 2-ways, sound the way that they do. It is interesting that JBL chose to stick with that compromise.

I don't regret buying the 4430's, even if I don't keep them in the long run. I need something good sounding now. They can serve as a semi-model for the 4343... helpful as something very real and very JBL, as you pointed out.

Thanks, Ian for the technical drawing accurate to scale and could take measurements off of (yeah, I can handle stuff like that). Thanks also for the photo and for the references (which I have started checking out).

I can do this. It will work (self pep-talk).

Later,
Monte

[Ian Mackenzie]

Thats cool Dude, see you in JBL Heaven.


Refer to the 4343B pdf for all the measurements,

Have fun

Ian

[Jakob]

Originally posted by Ian Mackenzie
Monte,


I added a set of JBL 077 slots, this was a quantum leap, I had an Altec 3 way 4333 monitor, and then later added 8 inch Audax mid cone to make it a low cost 4 way.

Ian

What kind of Audax 8"-drivers are You using? And in what range?

-Jakob

[Monte]

I had a thought or question. It questions the thought of *why start over with an entire new box*?

Is the 4430 box suitable (in the highest quality sense) for the LF cone (the 2235H that comes with) in use from 300 Hz and below?

But what about this? Leave the 4430 box alone and set another box on top. The new box would, I hope, properly house a 2121H midrange cone and a 2405H diffraction slot tweeter, according to correct volume engineering. Sort out the crossovers. Thus we have a 4 way system where each driver is operating in its best Hz environment.

Is there something inherently flawed with the 4430 box that could NOT be fixed with this plan?

Thank you for your thoughts.
Monte

[Robh3606]

Hello Monte

"But what about this? Leave the 4430 box alone and set another box on top. The new box would, I hope, properly house a 2121H midrange cone and a 2405H diffraction slot tweeter, according to correct volume engineering. Sort out the crossovers. Thus we have a 4 way system where each driver is operating in its best Hz environment."

Might work just have to work out the spacing between the midrange and woofer. Looks like you have some room between them with the 4343. You also may be able to make a 2122/2123 module to mount inside where the 2344 is now. It does not take to many cubic inches to load them I think 1/4 ft. Would effect your box tunning some but it might work if the spacing does not work out right.


Rob

[Monte]

Thanks, Rob

0.4 – 0.5 ft3 was specified for the 2121/2123. Just checked. 0.4 is what the enclosure document specifies. 0.5 is what the 4343 actually has.

And yep, it could certainly be installed there. Remains to be seen how the decrease in volume would affect the bass. The way it is now, the 4430 as is, has the same internal volume as the internal FREE volume of the 4343b with it's own 2121 sub-enclosure (that is subtracting off the 0.5 ft3 sub-enclosure). However, making the similar change to the 4430--installing a 2121 sub-enclosure-- would decrease the internal volume by about 10%. How much does that eliminate bass response?

Or if I put the 2121 on top, it remains to be seen (I mean heard) if it is too far separated. Hmmm.

***Wait---I think I've got it!***

Take out the 2425H/2344. Cover the hole with a board that seals really well. Turn the 4430 upside down. The trestle (attached stand) is now on top. Remove the trestle. Make a grill that covers the entire 4430 (and I wanted to do that anyway). For that matter, make a matching grill that covers the new second box that sits on top and contains the 2425H/2344 which is along side a 2121H MF cone in it's own 0.5 ft3 sub-enclosure and also somewhere the 2405H UHF diffraction slot tweeter & crossovers. It needs no port, I guess.

The 2121 MF cone is close to the 15" woofer. The size of the woofer enclosure is a correct 5 ft3. The 2344 is alongside the 2121 so that it does not sit too high (the upper box would probably be a little wider). Anyway, that would put the 2344 about 3 1/2 ft. high, which is probably fine. Voila. The 4430-pseudo-4343. "The poor man's 4343."

Hey, maybe I can use that vacated hole to put in some sort of passive radiator. Heh-heh.

Something for me to think about!!

Later, Monte

[Robh3606]

Hello Monte

That might work! Half the fun is figuring it out! Looks like you got a handle on things send some pictures when you can. I would like to see how it eventually works out.

Rob

[Ian Mackenzie]

Guys,

The Audax HT 210 is an 8 inch high sensitivity @ 98 dba paper cone mid which requires about the same rear loading as the jbl 2121/2123.

The bandwidth is 200 - 5k and smooth as a babies bottom..well you know what I mean. It is a a nice low cost start up if to running a 3/4 way. I ran them from 300 - 1250 hz.

Ps These driver are no longer in use as I finally snared a pair of JBL 2122 10 inch mids.

I have not decided to sell them yet but if any of you dare take the leap of sonic excellence to a precision 3/4 way send me a pm.

The 2344's are also in the same category as I am going pure 4345. PM's accepted for any ideas or questions on roll your own JBL monitors.

The stacked HiFi tower was what I had in mind at the start of the thread and is a good way to experiement, my only thought is to try and make sure the horns/slot are about ear height in the listening possy. That seems to be important.

At least you can play with the combinations and see/hear the differences. If you like it, you can enjoy it while you are crafting your composite cabinet.

Ultimately, the best accuracy is be the result of pure piston range over the entire range which is where the 4343 was a winner.

HiFI World Mag once described the 4343 as the B&W 802 answer for Jazz , Blues and R & R, but at worthwhile levels...I tend to agree.

For the would be diy 4343 fans here is my 1st effort 20 years on, and they still hold own against anything else and were used here to flatten a 21st birthday crowd with 1400 watts of bi amped power. (Actually my brother in law's 21st at a footy club in 1982!)
They have since also seen service in live production and the odd Ballet.

We got tired of it after a while with the boxes weighing 400 Ibs each..bursting our balls I mean.

Ian

[Tom Loizeaux]

Monte,
After my experiences with Altec and more recently JBL pro monitors, I think you would be very happy with a system driven by JBL pro componants. I fell in to my current mode of rebuilding and rehabbing JBL studio monitors without making this my plan. I've enjoyed this and have learned a lot. But, if I wanted to just jump to a very satisfying speaker system without the long road of work and experimentation, I would buy the GS Kit 11 from Gold Sound. They sell this as a kit of JBL componants, or you can order these with their cabinets as well. I think building the cabinets from their plans (included with the kit of componants) would be the way I would go - only because find pleasure in projects like this. Their GS 11 consists of a pair of JBL 2235H woofers, 2118H 8" mids, 2404H "baby cheek" tweeters, as well a their 3-way passive crossovers. These are some of JBL's best drivers and would work very well together to give you a wonderful sonic presentation.
I don't have any conection to this company, nor have I tried any of their systems, but from my experience with many of JBL's speakers and monitors, I'm sure these would satisfy many JBL fans. Their web address is www.goldsound.net

Good luck and keep us posted.

P.S. Anybody out there tried these?

Tom

[MikeM]

Originally posted by MikeM
I wouldnt go as far as saying i was having trouble with it its a nice unit. I used to drive myself nuts with adjusting reajusting so i said the heck with it and went single amp. think I noticed was a Blurr in imaging ect. I used the 5233/4 with my 4350's before mono block lowend and audioresearch tube highend with staggering results. resolution was fantastic. Wish i had more room here. Thanks for the info!

Keep in mind if one wants to "upgrade" the 4430 with a midrange that the midrange used will have to be part of the time alignment . That means the voice coils all must line up togther. Bad news midrange will be behind the baffel board. unless of course you time align with some eq divice in triamp mode