L-19 & 4301b

[Figge]

what´s the difference between the L-19 and 4301B?

[Alex Lancaster]

The L19 was the "home", the 4301 the "pro monitor", same components, same sound, the home version has slightly better cabinetry; They are great for their size and price, they were my first JBL´s, I sold them, but now have 6 of them.

[Figge]

ok but whats up with the "B"?

[4313B]

The 4301B, 4311B, 4313B, 4315B, 4331B, 4333B, 4343B, and 4350B all used SFG ferrite magnetic structures in place of the alnico magnetic structures.

[4313B]

Studio Monitor Series (http://www.jblproservice.com/pdf/Systems%20Reference%20Charts/Studio%20Monitor%20Series.pdf)

4301 Network Schematic (3103) (http://www.jblproservice.com/pdf/Network%20Schematics/3103%20Network.pdf)

[4313B]

L19 and L19A

[Figge]

so L-19 = 4301 and L-19A = 4301B ?

[Figge]

did the changing of magnets bring impovments of the sonic performance?

[4313B]

The SFG ferrite motors reduced distortion and increased power handling. There is actually a Tech Note on the whole mess somewhere. The old alnico V motors also were susceptible to degaussing. The new alnico motor in the 1500AL has been specially designed to withstand degaussing.

[Figge]

ok! i´m bidding on a pair of mint 4301B. if i get em im gonna take them to my buddies studio and swap with the L-19:s. and se if he likes those even more!

[Robh3606]

Hello Giskard

This looks to be a part of the Tech Note

Rob:)

[Figge]

about the magnets: was it only the woofers in L-19/4301 that used alnico? or did the tweeter too?.


those curves looks fine! so we can expect the 4301B to actually sound cleaner than the L-19?

[boputnam]

Originally posted by Figge
ok! i´m bidding on a pair of mint 4301B. :coolness:

Prepare to be amazed...

[Robh3606]

Hello Figge

All of the various tweeter variants Le-25, Le25-2,-4 Le-26 where all ferrite. The woofers are where the change over from Alnico to Ferrite occured.

Rob:)

[Figge]

Originally posted by boputnam
Prepare to be amazed...


Cool!



All of the various tweeter variants Le-25, Le25-2,-4 Le-26 where all ferrite. The woofers are where the change over from Alnico to Ferrite occured.


i suspected something like that.

[Figge]

well i was high bidder at $153,71 when it ended. i´ll return with a A/B when i get them into his studio. i think that is pretty cheap for a nice pair of 4301B.

[Figge]

well for starters the boxes arent the same. the 4301B is much deeper.

[Figge]

ok now we got the 4301B:s up and running in his studio! man these little speakers really sing! the L-19 was blown away! 4301B:s had a more complete sound, much deeper cleaner bass. and strangly it had much better highs too! we both fell in love with them! he was really amazed how these small speakers could have such big sound! $150 was a steal in my opinion! heres a pic.

[boputnam]

Hey, Figge...

That is a VERY clean pair of 4301B's, my friend. Enjoy, enjoy, enjoy. That will stand-up well to speakers twice their size - JBL got lucky on this one!

:coolness:

[Figge]

Originally posted by boputnam
That will stand-up well to speakers twice their size


i´m shure they will!! they are just amazing when used as intended, in a very small studio, in a near field position! probably hard to beat!

[boputnam]

Don't limit them to that. I use them as near-fields, and also in the shop. EVERYONE that visits the shop asks what they are, and where they can find some... :yes:

[4313B]

Nice pair!

I always was a sucker for 4301B's :yes:

[Figge]

Originally posted by Giskard
Nice pair!



they are beutiful! 1 owner from new in mid 80:s! they are MINT! cant believe i got em for $153.

[Figge]

i guess these speakers havnt been used at all the last 5 years! the foam looked perfect when we hooked em up! but after a couple of hours use the foam disparted from the cone at an area about 1,5". i told him to cool down while daddy fixes new foam kits! now i gotta find a good place dealing with this kinda stuff!

[boputnam]

Emial Rick Cobb at: [email protected]

He's the best. Tell him you need a 116H surround kit, and test-tone CD. Tell him the Forum sent you...! :yes:

[Figge]

tnx bo! u r a great guy! i have now mailed him and cant wait for his reply. i also talked to jbl repair center here in sweden. i had to send the woofers in for service. when i asked if i could buy just the surrounds i think he was pissed! and wanted to end the conversation.


once i get the surrounds: is there a fairly good chance that an "amature" like myself is going to pull this off? are they gonna sound as amazing after my interference as before?

[Figge]

yipiii! got reply! $39,99 including insured shipping to sweden! unbeliveble! i thoght it would cost twice or more! Highly recomended!!

[boputnam]

Originally posted by Figge
...once i get the surrounds: is there a fairly good chance that an "amature" like myself is going to pull this off?

Yea, go here:
Resurround Step-by-Step (http://audioheritage.csdco.com/vbulletin/showthread.php?s=&threadid=469&highlight=resurround+stepbystep) Thread


...are they gonna sound as amazing after my interference as before? :yes:

While a recone is always a better solution on a vintage transducer, you may not need it. The quality of your pair suggests you might do fine with only doing resurrounds. As a first step, do the resurround. Make sure you get the 30Hz test-tone CD...

[Figge]

ok. i have read that thread before and i think its super! it is gonna be of great help.

I´ll send him the money first thing next week, so hope they get here quick. now they have disparted about half an inch more. he uses them anyway. but told him to play them at low volumes. and if they go more than 1,5" more: unpugg em! and i´ll show up with the L-19 again as backup.

[boputnam]

Hey, Figge...

I'd GRAB those 4301B's away from your friend. :scold:

There might be increased risk of popping the voicecoil out of the gap with a weakened / breached surround, and that would be bad. With only the spider remaining intact - and it too may be weakened - you risk extra damage that is not necessary.

[Figge]

u r right bo! i´ll drive over those l-19:s for the time it takes to get the 4301:s repaired! he is getting more and more into the world of jbl:s and he understands what these speakers are! and fully agree that the l-19 will go for a while in there, fore the sake of the 4301B:s. let me tell u he really love those 4301:s!.

[Figge]

ok! now i got the kit home! gonna start right away with the refoaming....i´ll get back l8er with some results! this is gonna be quite exiting i think :)

[Figge]

ok! thanx to bo i have now made my first resurround! it went like on a rail! i used bo´s step by step thread! combined with rick´s instructions...however it was a little trubble gluing the surround to the frame. but it was no real problem. now they are like new! i could not hear any difference after the surround change....

as bo said earlier: rick cobb is the best! well he must be! the kit fitted perfectly. highly recomended!

[Figge]

as dead as disco:)

[Figge]

let´s rock!

[Figge]

Originally posted by Figge
let´s rock!



oh no u aint! not without me!

[boputnam]

Hey, Figge...

Nice looking job! :thmbsup:

How's the sound, now?

:dancin:

[Figge]

to me it sounds as good as it did before the foam started to dispart...maybe a little stiffer in the deepest bass, but i guess they will soften up while using?

[andresohc]

That sure looks better then my first re surround:) . Great job.