JBL Polarity Convention

[boputnam]

That is my read, exactly.

I last night thought of annotating the schematic, as follows...

[4313B]

Ok, so is there still a problem with my initial statement?

[boputnam]

I sure don't think so.

This whole issue makes me sometimes...

[4313B]

Alrighty then!

You guys sure had me going late last night. I was so tired I couldn't see straight.

[boputnam]

Originally posted by boputnam
I'll have a look at it tomorrow...

I seem to have been feeling the same way.

[MJC]

Originally posted by Giskard
Ok, let me think about this again.

RED input terminal to RED wire to #1

RED #1 to #3 to WHITE wire to RED post on 112 driver. Cone would move in.

RED #1 to #6 to YELLOW/BLACK wire with FEMALE end to BLACK/MALE tab connector on LE5 driver. Cone would move out.

RED #1 to ORANGE wire to RED post on 066. Dome would move in.

I can see now that I temp. confused myself with this entire thread. I HAD the "new" L212s wired correctly. Then I changed the connections on the 2105s and then had to change them back after reading your statememts above.

[4313B]

Ok, so nothing was wrong with my initial post then right? It's just a bit confusing.

How is the system sounding these days?

[boputnam]

Originally posted by Giskard
How is the system sounding these days?

Ahh, the soothing wisdom of the Giskard.

At the "end of the day", the sound (to your ears, MJC) is really all that matters...

But "where" in Nevada? Pahrump? I spent nearly a decade in ol' Elko, and loved the place. But that was before Clark County stole the 702 Area Code...

*****

Oh, and...

Originally posted by MJC
I ... confused myself with this entire thread.

...troubles me a great deal. I stumbled into this near netherworld unknowing, but it explain a phasing conflct that arose from my pairing 4312's and 4313B's. No can do. It had never occurred to me there would be phasing issues within/between the same brand of cabinet, but alas, my ears told me . So, here we are, and many have/are struggling with attempting to resolve phasing issues that arise where least expected.

Don - I do promise to compile my findings on this, both by cabinet and individual transducer (even more important because networks are the final judge of active polarity). Getting closer...

[MJC]

Originally posted by Giskard
Ok, so nothing was wrong with my initial post then right? It's just a bit confusing.

How is the system sounding these days?

The system is sounding really great, with 2 subs, put one surround box is still short a 112a. I haven't seen any 112a for sale in almost a year.
In the next couple of months I'm going to build 2 more boxes, mirrored image for the 2 main speakers. I'm curious as to how much of an improvement there will be for 2 channel play.
And add .0056uf polystyrene pypass caps to all the 066s.

[MJC]

Originally posted by boputnam
Ahh, the soothing wisdom of the Giskard.

At the "end of the day", the sound (to your ears, MJC) is really all that matters...

But "where" in Nevada? Pahrump? I spent nearly a decade in ol' Elko, and loved the place. But that was before Clark County stole the 702 Area Code...

I'm in Douglas County, 10 miles south of Carson City. I have to go to Elko next week to do an install job- replacement doors, not HT
Although there are quite a few more people in and around Elko, especially going toward Lamoille, there is still alot of things they don't have, like a Home Depot.
I was over by your way 2 weeks ago, working at Clear Lake and in Redding.

[boputnam]

Originally posted by MJC
Although there are quite a few more people in and around Elko, especially going toward Lamoille, there is still alot of things they don't have, like a Home Depot.

Good fortune appears in the least expected ways (and places...) .

[4313B]

Originally posted by MJC
I'm curious as to how much of an improvement there will be for 2 channel play.

Ok, you have two "stock" so you can A/B right? I'm currently designing new enclosures for my L212's as well.

As soon as you stop looking for 112A's they should show up

[boputnam]

Oh boys-and-girls, here it is, the post you've been thirsting for! Excerpted from a pm I received...

Hey Bo, I'm like a 40+ yr old kid in a candy store. Got my (L100) babies back today. OK, Here's what I found out. The earlier model, #237954A the one with the push connectors has a woofer 123A-3. This is the same for the later model #269707A with the twist connectors, 123A-3. ...my son even sent me the owners manual which came with the later speakers. It says:

"Special Note: To maintain consistent polarity with other JBL models, current L100's (commencing with serial number 47100 and easily identified by the foam ring surrounding the HF direct radiator) are reversed in polarity with respect to earlier units. If early and current L100's are utilized in the same room, the early units should be connected "out of phase" with the current L100's. Thus, if the wires from the negative terminals of the amplifier are connected to the black input terminals of early L100's, the negative wires for current L100's should be connected to the red input terminals."

So, all my tedious posts and nagging pursuits of this legacy are vetted. Vetted by the L100, dammitt!!! We here long ago surmised polarity issues were the reason for the switch to the 123A-3 (a negative transducer) from the 123A-1 (an unlikely positive transducer) in later model L100's.

Hat's off to "invstbiker". Nice!

And, interestingly, JBL think's it unneccesary to cross-wire AT the transducers (inside the cabinet); JBL suggest doing it at the cabinet binding posts is sufficient. Okie-dokie then. The old AC-DC thing...

[Mr. Widget]

Bo,

It is apparent that you may now retire from the forum. Your mission accomplished. That nagging at the back of your mind finally quieted.

Congratulations! Few of us so plainly reach the end of The Path... the End of Suffering. Tell us what it is like under your Banyan Tree.

Widget

[boputnam]

Tell us what it is like under your Banyan Tree.

Thanks, friend.

It is exactly like 4345's running off some oh-so effective QSC's and a nice analogue EQ barely affected by the Adcom pre-amp...



My best always to you, and Ms. Gadget...