Newbee w/ Modified 4311B's [Archive] - Lansing Heritage Forums

boputnam

07-27-2007, 03:27 PM

I've just installed D123-A3's (corrected polarity) in my 4311B's. I have no idea.

The D123 was designed for a specific purpose. That said, the 4311B was designed with the 2213H. You are on your own...

Did you model the woofers using their Thiele-Small (http://www.thielesmall.com/) parameters and the 4311B dimensions? What do your models say...? :hmm:

Zilch

07-27-2007, 03:55 PM

It's 123A-3s presumably, no "D."

And there's no polarity issue to correct, I don't believe, but I'm not going there again, nope.

http://audioheritage.org/vbulletin/showthread.php?t=12757

Swapping the drivers will only devalue them if you tell, of course.

Unless you hype the Alnico angle as making them more desirable, and some fool falls for it. "Fools," actually, 'cause it takes more than one to boost the selling price.

Send me the POS 2213Hs you took out, please.... :yes:

boputnam

07-27-2007, 07:09 PM

It's 123A-3s presumably, no "D."Well, I started down that route too, Zilch, but then thought maybe the OP really meant the D123, an old-school AlNiCo motor transducer.

Indeed, if it is the 123A-3, the polarity is identical to that of the 2213H (these are both negative) so it should be connected as the 2213H was.

We need to know 'zactly what is going on... :blink:

KenMiles

07-27-2007, 09:00 PM

I have no idea.

The D123 was designed for a specific purpose. That said, the 4311B was designed with the 2213H. You are on your own...

Did you model the woofers using their Thiele-Small parameters and the 4311B dimensions? What do your models say?

Honestly, Bo, I Homer Simpson’d it. I'm unable to comprehend Thiele-Small parameters. My intelligence has holes, kinda like Homer’s doughnuts.

It's 123A-3s presumably, no "D."

And there's no polarity issue to correct, I don't believe, but I'm not going there again, nope.

http://audioheritage.org/vbulletin/showthread.php?t=12757

Swapping the drivers will only devalue them if you tell, of course. Unless you hype the Alnico angle as making them more desirable, and some fool falls for it. "Fools," actually, 'cause it takes more than one to boost the selling price.

Send me the POS 2213Hs you took out, please....

Hi Zilch.

Thanks for the heads up. You’re probably right about the ‘D’- I’m not inclined to take the woofer out to take a look. The 123-A3 woofer frame has the same robust design as the 2213H, with the large rectangular spokes.

On polarity, I defer to Homer. Homer connected a small battery to the posts and found the 2213H pushed outward with the positive to the red. Homer tried the same method and found the 123-A3 pushed inward. But Homer denies any wrongdoing...

The 2213H’s are in a friend’s hands now. I guess I’ll have to test the strength of our friendship to find out how the 2213H’s sound in the 4311B’s. (It’d been years since I last heard it)

Did you say 'fool'? Homer!

Signed, Homer, uh, Ned, eh, KenMiles. :)

boputnam

07-27-2007, 09:51 PM

Honestly, Bo, I Homer Simpson’d it. I'm unable to comprehend Thiele-Small parameters. My intelligence has holes, kinda like Homer’s doughnuts. :rotfl: That's OK - swapping is fun, but can result in unintended consequences... There's some cool freeware to help you model box response, and the T-S parameters are pre-loaded in libraries - helps avoid mishaps...

On polarity, I defer to Homer. Homer connected a small battery to the posts and found the 2213H pushed outward with the positive to the red.:no: Impossible.

Homer tried the same method and found the 123-A3 pushed inward. :yes: That is the proper response.

So, is the replacement transducer the D123? Regardless of you getting inverse results from "your" polarity test on the 2213H, the D123, 123A-3 and 2213H should all test the same (cone in on (+) signal). I'm quite confused...

boputnam

07-27-2007, 09:53 PM

I’m not inclined to take the woofer out to take a look.You should do this, Ken. Too many questions for a simple LF swap...

Zilch

07-28-2007, 01:42 AM

On polarity, I defer to Homer. Homer connected a small battery to the posts and found the 2213H pushed outward with the positive to the red.Only if they have been reconed using the wrong kits.

Again, have Homer send me the 2213Hs, that we might resolve this matter in reasonably short order.... :yes:

KenMiles

07-28-2007, 07:38 AM

Only if they have been reconed using the wrong kits.

Again, have Homer send me the 2213Hs, that we might resolve this matter in reasonably short order.... :yes:

No recone, original 1979 or 1980 cones. My brother owned the 4311B's for most of these years but was SO desperate to own a computer that I was able to trade a computer for my old JBL's. Talk about a ripoff! But it's fair, given the deal he got on them from me.

Jeepers, Bo, Zilch, JBL-meisters, I'll have Homer confirm the polarity of both drivers. Maybe there's a number Homer didn't take note of, like 2213H-1 or something like that.

Meanwhile, regardless of what the T-S calculations may say, the speakers do sound good, especially the well defined bass. The bass is only there when it's really there, and goes deep, if that makes sense. The only weird thing is the reverse polarity mid-range. I, er, Homer, does believe he's hearing the doughnut hole in the mids, especially when A-B vs. (corrected) Sonab OA-14's.

You know, Zilch, Homer gets lost in that NorCal freeway system - I mean he thinks he's headed to Hayworth and winds up taking a left(ist) turn in Berkeley!

:) KenMiles

boputnam

07-28-2007, 07:51 AM

I was curious how the older alnico magnet woofers would sound in them. See, your OP indicated the replacement driver has an AlNiCo motor - correct? Then it is certainly not the 123A-3. :no: My guess is, it is the D123.

I'll have Homer confirm the polarity of both drivers. Maybe there's a number Homer didn't take note of, like 2213H-1 or something like that. Yea, Ken - do confirm the driver number, and it would be good to double-check the cone excursion. (+) to red should give cone in movement.

pelly3s

07-28-2007, 09:26 AM

someone at jbl could have been drunk and inverted the polarity on some mags (hey you never know) :cheers:

KenMiles

07-28-2007, 05:05 PM

Pelly, what Homer gathers, (and Homer doesn't recall from exactly where) JBL's initial solutions to meet the current polarity standard came in a mixed bag- drivers were changed, some speakers were worked out in the internal wiring, and some speakers were simply cross-wired at the connector posts.
What Homer? :bs:

They were drunk?

Okay, I'll get off my box now-

:) KenMiles

Zilch

07-28-2007, 07:30 PM

Okay, I'll get off my box now--"... and go determine what drivers are actually IN my 4311Bs."

["OH, and how I have them CONNECTED, too...." :p ]

KenMiles

07-28-2007, 08:55 PM

"... and go determine what drivers are actually IN my 4311Bs."

["OH, and how I have them CONNECTED, too...." :p ]

Hi Zilch.

Homer is very reluctant to remove the woofers again. When he originally removed the 2213H's, the seal became an adhesive over the years which tore chips of particles away from the baffle. Homer's removed the woofers twice, which each time removes more chips.

When I have Homer remove them again, it'll be specifically to install gaskets to remedy that problem, and possibly repair the damage to the baffle edges.

The current install for the 123 A-3's is wires 'reversed', with the green wire with the black stripe (positive) connected to the black driver post, the green wire (negative) to to the red driver post.

At the time of the swap (last week), Homer confirmed checked the total system, which the woofer pushes out when positive battery goes to the red post on the back of the cabinet.

The only other evidence Homer can provide is a description of the 123 A-3 drivers. Unlike the 123 A-1's, they have robust rectangular spokes. They're also 8 ohms.

The guy who Homer bought them from said they came out of L100's, which story fits- they're painted semi-gloss black (not grey as their 2213 professional counterpart).

The magnet housing is also distinctly different (smaller diameter) from the original 2213H, but the frame casting spokes are the same as the 2213H.

There's a pair of 2213 woofers currently listed on ebay. See:

http://cgi.ebay.com/JBL-2213-123A-3-Woofers-4311A-L100-NM-Very-Nice_W0QQitemZ110153530556QQihZ001QQcategoryZ50597 QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

There's a pic showing the rear view of the drivers, which is identical to the 123 A-3's except for the color.

Otherwise, can you'll wait until Homer is ready to install gaskets? I'll lend him my camera so he can post pics.

ThanX,

:) KenMiles

Zilch

07-28-2007, 10:32 PM

The woofers, if they are indeed 123A-3s, are wired correctly. The green with black stripe is (-), and the solid green is (+).

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/4311B%20ts.pdf

KenMiles

07-28-2007, 11:17 PM

Wow- Homer had it all wrong but lucked out anyway! :blink:

The part I don't understand is, according to the schematic, if red is negative, why the woofer would push forward when battery positive connected to the cabinet red post- unless the 4311B meets the current standard at the cabinet posts. (???)

Oh, now I get it- the 4311B makes the correction in its wiring, add the mid is wired reverse from the woofer and tweeter too! (Schematic 3112B)

ThanX, Zilch

:) KenMiles

boputnam

07-29-2007, 08:08 AM

I was curious how the older alnico magnet woofers would sound in them. Again, alone, I remind of this quote in the OP.

If you do have the 123A-3 (and it "sounds" like you do, since now we learn these were sourced from some splendiferous L100's...) you are not getting that "AlNiCo sound".

:dont-know

Zilch

07-29-2007, 04:02 PM

123A-3 is indeed Alnico, Bo. 2213 was the pro equivalent.

There were no ferrite L100s, I don't believe. :dont-know

boputnam

07-29-2007, 06:58 PM

Yea, sorry... Ferhellsake - I should have known by the "A" designation.
Too many gigs this weekend to think straight about this stuff. I know better than to even begin to engage out here!

I was just plumb confused by the OP reference to the "D" prefix... :o:

Zilch

07-29-2007, 10:56 PM

The whole L100/4311 variant driver/crossover/polarity thing is so complex, there's no remembering it all. That means check the service manuals, find and re-read old threads, drag out a 123A-3 and put a battery to it, etc., etc., :blah:.

Screw it. I ain't answerin' no more inquiries about this. Fact is, it doesn't much matter what's in them or how it's connected, "It does not affect the sound."

Homer can handle it; he gets it right without any of that stuff.... :p

boputnam

07-30-2007, 08:17 AM

"It does not affect the sound." :shock:

Now, Zilch, you know better... :scold:

KenMiles

08-02-2007, 06:59 AM

Fact is, it doesn't much matter what's in them or how it's connected, "It does not affect the sound."

Hi Zilch.

Sorry this put you through so much. Homer is guessing polarity really mattered with the advent of subwoofers, but Homer's only guessing.

I've been listening to the modified 4311B's for about three weeks. I like the bass. Homer calls it 'tonal bass'- you can hear notes and texture.

Meanwhile, the musical chairs speaker rotation meant moving my Sony APM-22ES to another room to be matched with a Dynaco SCA-80. I wasn't certain of the Dynaco polarity, so I trialed both. Homer brought me a recording compiled using a signal processor. It has everything from low to high frequencies plus mixes of both. Curiously, there's a high frequency passage which is evident if played with the polarity hooked up one way, but is not evident when hooked up the other way!

I can send you a copy of this recording- is there a method of 'private messaging' on this site so that you can send Homer your address?

ThanX,

:) KenMiles

boputnam

08-02-2007, 07:40 AM

Homer is guessing polarity really mattered with the advent of subwoofers, but Homer's only guessing.Homer is right, but the guess is not restricted to "the advent of subwoofers". It matters a great deal, whenever more than one transducer is operating.

That said, most "consumers" might have first become aware of polarity with "the advent of subwoofers" as they encountered the "Polarity" switch on the rear of the sub cabinet.

You can send Zilch a "pm" - click on his moniker, and there you will see info about him and an option to "send a personal message". There are other ways, but this works...

KenMiles

08-02-2007, 08:02 AM

Hi Zilch, Bo, JBL enthusiasts-

Zilch, Homer was eating a doughnut when he'd realized why the high frequency passage shows then disappears. Homer'd forgotten he'd swapped the CD player! One is able to register the high frequencies while the other doesn't.

Doh!

Homer says he can send a copy of the CD anyway.

ThanX,

:) KenMiles

KenMiles

08-06-2007, 06:06 AM

Hi Zilch, Bo, JBL enthusiasts

I'd been auditioning my modified 4311B's for a little over three weeks now. When I cranked up the volume, it hurt my ears. I'd (foolishly) set the speakers were parallel to the walls. So Homer rotated my speakers about ten degrees inward- lo and behold, everything sounded way better at every volume level! Plus the bass really improved.

Uno, :blah:

KenMiles

08-15-2007, 07:05 PM

to Zilch, Bo, JBL enthusiasts

Hi Zilch. Okay, here's part of the puzzle, a pic of the back of one of my 123A-3 woofers.

http://i70.photobucket.com/albums/i91/KenMiles/JBL_123A-3_001.jpg
This view confirms the alnico magnet of the 123A-3

http://i70.photobucket.com/albums/i91/KenMiles/JBL_123A-3_000.jpg
An enlarged view of the badge.

Apart from this, Homer and I are not at all satisfied with the midrange performance of the 4311B. Homer just last night reversed the polarity of the mids- he says now understands why JBL reversed the wiring of the mids. The speakers sound way harsh with the mids wired correctly. But I'd like to audition them myself for a while. Homer is also curious how the reputed smoother 104H-2 mids would sound with the altered wiring.

:) ThanX,

Homer,,, eh, KenMiles

KenMiles

09-12-2007, 01:41 AM

Hi Zilch. Bo, JBL enthusiasts

Here's the latest modification, with 104H-2 replacing the LE5-10 midrange drivers. The speakers do sound less harsh with the 104H-2. Listening over time will tell.

http://i70.photobucket.com/albums/i91/KenMiles/4311B_000.jpg

The mods include 123A-3 woofers, 104H-2 midranges, with midrange wiring switched. Thanks to Zilch, Bo, and Homer for all their help.

:) KenMiles

KenMiles

09-26-2007, 08:08 PM

Hi Zilch, Bo, JBL enthusiasts

I've been listening to my modified 4311B's for some weeks now. So far, I've found the most significant improvement by changing amplifiers.

http://i70.photobucket.com/albums/i91/KenMiles/ST-120_001.jpg

This pic shows a Dynaco ST-120 power amplifier aquired in a trade for the original LE5-10's from the 4311B's. The Sansui AU-717 was split at the 'pre-out' switch, then the ST-120 connected to the AU-717 pre-amp.

This improved the sound and smoothed out the harshness I was suffering, particularly at higher volume levels. I was amazed at just how much the ST-120 improved the sound. My favorite listening right now is an old LP, Bernard Herrmann's movie music from 'The Three Worlds of Gulliver'.

I also experimented using a Dynaco SCA-80 to drive the modified 4311B's. In all, I'd estimate the choice of amplifier EXTREMELY important to getting the best sound out of JBL's L100 family of speakers.

Homer suggested a Dynaco PAS-3 pre-amp, so that's on its way.

ThanX,

:) KenMiles

Rusnzha

09-26-2007, 09:14 PM

I set up my L100s with 123A-3s, 104H-2s, LE25-2s and charge coupled crossovers. It's amazing how good these things can sound if you put a some work into them.

KenMiles

10-18-2007, 12:57 AM

Hi Zilch, Bo, Rusnzha, JBL enthusiasts-

Here is my latest experiment. The PAS-3 and ST-120 are newly aquired eBay additions. The PAS-3 still needs four 12AX7, and the ST-120 is in need of Dynaco's TIP revision. I aquired a second ST-120 because my older one is in cosmetic pain, plus Homer said it was ugly.

http://i70.photobucket.com/albums/i91/KenMiles/ST-120_012.jpg

http://i70.photobucket.com/albums/i91/KenMiles/ST-120_010a.jpg

Homer wasn't aware of the Dynaco TIP mod until he got the unit and connected it. It distorted wildly on certain music passages. But that's the beauty of buying used electronics on eBay- there's so much to learn!

Homer says it'll be a couple weeks before everything is ready to run.

~~~~~~

I hope I'm heading in the right direction with this. When I play Public Image Limited's live recording 'Paris au Printemps' on my other ST-120, I'm finding the aged Dynaco amp wholly inadequate. It seems to run out of headroom at the volume level Public Image Limited demands. The ST-120 has a sweet, natural sound, but may not have enough grunt to feed the appetite of my modified 4311B's.

The PIL record does come to life when my JBL's are driven through the Sansui AU-717.

ThanX,

:) KenMiles

Rusnzha

10-18-2007, 02:07 AM

I'm not really familiar with that amp, but it looks like it may be missing one of it's power output transistors.

KenMiles

10-18-2007, 07:05 AM

Hi Rusnzha

Yeah, looks funny, huh? The power circuit shares the heatsink design used for the left and right channel circuits. The left and right circuits are opposite each other on the chassis layout.

A buddy of mine thought his ST-120 was missing a transistor. An enterprising eBay seller offered to sell him one! http://slotblog.net/style_emoticons/default/laugh2.gif

ThanX,

http://slotblog.net/style_emoticons/default/smile.gif KenMiles

Thom

10-19-2007, 07:15 AM

I have no idea.

The D123 was designed for a specific purpose. That said, the 4311B was designed with the 2213H. You are on your own...

Did you model the woofers using their Thiele-Small (http://www.thielesmall.com/) parameters and the 4311B dimensions? What do your models say...? :hmm:

Never could have been a D123 unless someone took a saw to the frame. D123's won't front mount without heavy modification.