4311 polarity?

[Figge]

i read here earlier that +from battery on black terminal should make the woofer jump out. i checked this on my 4311:s and it did do that on one of them. the other one i opened and looked. i saw that the black cable was connected to black terminal on the 2212.so i swapped...i did the right thing right?


next: i unscrewed the le5-2 mid in the same speaker to find out that the red was on red. is this right? shouldnt it be swapped? so that it´ll be red on black?

the le25 tweeter was made so u couldnt swap. they fit only one way.




Figge

[Figge]

Originally posted by Figge
next: i unscrewed the le5-2 mid in the same speaker to find out that the red was on red. is this right? shouldnt it be swapped? so that it´ll be red on black?





i meant the black should go on red? not black--->black.

there is no red cable....it was white.

hmm. guess i´ll check the polarity upstairs too:screwy:

[johnaec]

I've often wondered if there was an objective way of testing the polarity between components when installed, including the amplifier circuits if using active crossovers. The only way I can think of is to check the output at the crossover points - out of phase would put the sound 6 db down at crossover hz, right?

John

[boputnam]

Originally posted by Figge
the le25 tweeter was made so u couldnt swap. they fit only one way. They should have all been made that way... :banghead:

No, Figge, the positive signal to red shouldn't "necessarily" do either in or out. It just depends upon the JBL transducer design. Most JBL are negative (cone in). But, a few are positive (cone out).

First order, connect all BLK to Black terminals JBL's - that will honor the JBL design, rest assured. For the 2212's - don't worry if they're positive or negative - JBL made things to be wired simply, in your case, GRN to Red (2212), and BLK to Black. Same with the LE5-2 (2105), with WHT to Red and BLK to Black. For the HF (LE20-1) Red to Red.

And, to johnaec, I've not tested the entire circuit, but if you're interested in knowing how a network changes phasing in a cabinet, you can use that "Cricket" device (Search the Forum). It may be this can be used further upstream, but I've not tried it.

Here is the Link to the 3111 Network (http://www.jblproservice.com/pdf/Network%20Schematics/3111%20Network.pdf) for Figge - which in this case is unusually clearly labelled. ;)

And, once there, you can edit the address and back-into JBL's handydandy database of things interesting mostly to us Forumites...

[johnaec]

That "Cricket" looks interesting, but at ~$300 I'll have to look for a loaner... :rolleyes:

[Figge]

tnx bo! so everything is alright then? black ----> red on 2212 and black ----> black on mid.

that makes me wonder how to hook up the amp. should red from amp go with red on speaker? or?

never thoght of this untill i read some stuff here. obviously someone had done something inside the speaker and when putting it together assumed black goes with black.

[Figge]

well i now that the crossover u posted says otherwise. red----->red on woofer. that would make a cone in on possitive signal right? i honestly do not understand this.

[Figge]

well been looking around and found out that 4311 has the 3112 network. is it the same as 3111?

[boputnam]

Well, it seems I was hasty - busy chasing a Ground Loop around the house...

You're correct the 3112 network goes with the 4311 and the 2212. Here's a Link for the
3112 Network (http://www.jblproservice.com/pdf/Network%20Schematics/3112%20Network.pdf)

No, the two networks are not identical - the 3112 has an 8uF cap in-place of the 13.5uF cap in the MF filter.

Yes, the Red -> Red on the 2212 should move the cone in on positive signal. Although, I've never tested the 2212. If you're game, grab a old 9volt and put (+) to Red, and (-) to Black - and post your findings. This will work with a AA battery, too, but you've got to use some wire leads.

But remember, it doesn't matter - the difference is indistinquishable (inaudible). What matters is to honor the in-cabinet phasing between the three transducers, which in the 4311 to me looks:

HF (+)
MF (-)
LF (-)

[Figge]

tnx bo. so should it be black ---> black on the 2212? the network u posted for 3111 says so but 3112 didnt say. but i asume it shoud.

then when i test with a AA on the terminal back on the speaker the woofer go in.

so then it makes sense....or?:hmm:




figge

[boputnam]

Originally posted by johnaec
That "Cricket" looks interesting, but at ~$300 I'll have to look for a loaner... :rolleyes: Yea, John, it is real useful. It has saved me quite a bit of confusion, and recently, repairing some wedges it avoided me having to take others apart to confirm comformity (hmm... I like that!), enabling a quick system-wide multi-wedge check.

The folks at Northern Sound and Light (http://northernsound.net/Sales/testequipment/galaxyaudio/cricket.html) have some of the best pricing...

[boputnam]

Hey, Figge...

Yea, that is all good. I will note the 2212 is negative, as expected.

GRN -> Red terminal on the LF
(you can notice the GRN wire connects through to the Cabinet Red binding post).

How's it sound?

[Figge]

tnx alot for helping out. havent done any sound testing yet. 23:50 here. guess the neighbors would kill me. but since both LF:s were red---->black. i guess it will be a big difference. strange when i bought the speakers one of them had red->black and the other black->red. well well.

[Figge]

yes now it sound right! i think the lower mid region was improved alot. vocals seem to flow out in a totaly different way.

now they even rock a little more :band:




tnx bo!