are all E140's the same? (pics)

BassGreaser · #1 05-02-2011, 07:37 AM

I will be getting a JBL E140 tomorrow! (pics below) are specs the same on all the E140's built from the 80's - when JBL stopped making them? Also how do I find out what year my speaker is?

jnewmark · #2 05-02-2011, 08:46 AM

Was that 15 reconed ? Usually, when they are reconed they don't show the label on the back of the magnet, like this one. I would also test the terminals, as, for a time, JBL used the red terminal as negative, black for positive. Nice speaker though, one I have used since the '80's in a 215 cab. very sweet tone and surprising mids. I have slapped with no problem with the E140's. Heavy as hell, but, worth it to me.

BassGreaser · #3 05-02-2011, 08:48 AM

it has been reconed.. I am bummed it is missing the back label plate, but I guess it's not that big of a deal

BassGreaser · #4 05-02-2011, 12:40 PM

What I am really wondering is.. Are all E140's the same reguardless of the year they were built?

BassGreaser · #5 05-03-2011, 06:49 PM

Quote:

Originally Posted by jnewmark

I would also test the terminals, as, for a time, JBL used the red terminal as negative, black for positive

How do I test the terminals to see which is + and which is - ?

4Mal · #6 05-03-2011, 06:56 PM

Pretty much an E140 is an E140 assuming it was reconed using a JBL kit and by a thoughtful reconer. baattery test the speaker. Hook the neg ative side of the battery to black, then touch the positive side to the red - if the cone moves out, red is positive, if back, then it is reversed.

I've never heard of JBL reversing red & black before and that seems pretty odd to me ...

coreyfyfe · #7 05-03-2011, 07:07 PM

Quote:

Originally Posted by 4Mal

Pretty much an E140 is an E140 assuming it was reconed using a JBL kit and by a thoughtful reconer. baattery test the speaker. Hook the neg ative side of the battery to black, then touch the positive side to the red - if the cone moves out, red is positive, if back, then it is reversed.

I've never heard of JBL reversing red & black before and that seems pretty odd to me ...

Helpful:

http://www.jblpro.com/pub/technote/tn_v1n12b.pdf

BassGreaser · #8 05-04-2011, 04:53 AM

Quote:

Originally Posted by 4Mal

Pretty much an E140 is an E140 assuming it was reconed using a JBL kit and by a thoughtful reconer. baattery test the speaker. Hook the neg ative side of the battery to black, then touch the positive side to the red - if the cone moves out, red is positive, if back, then it is reversed.

I've never heard of JBL reversing red & black before and that seems pretty odd to me ...

It looks like it has been reconed with the right kit judging from a non-reconed E140 and mine. Oh thanks for the battery tip!

BassGreaser · #9 05-04-2011, 04:55 AM

Quote:

Originally Posted by coreyfyfe

Helpful:

http://www.jblpro.com/pub/technote/tn_v1n12b.pdf

I read through that link and couldn't really find anything where it says about the connections... or maybe I just don't know how to read spec mans

coreyfyfe · #10 05-04-2011, 06:50 AM

Quote:

Originally Posted by BassGreaser

I read through that link and couldn't really find anything where it says about the connections... or maybe I just don't know how to read spec mans

It talks about why they were reverse and which one were reversed, and if I read it right, says that the E140-8 speakers were negative (ie reverse) so I'd definitely check them with the battery.

Any one who might know better than I, I have a K140 in my B-15 and have been wondering the same thing. I've never used and extension cab with it, but I have used my countryman type 85 on the output with odd results which is what initially got me on the hunt of the whole reverse polarity thing. I haven't gotten a chance to try the battery thing, but might have a go some time this week. I guess my question boils down to: would the speaker being connected in reverse polarity change how signal is passed through a speaker level DI like the countryman?

lbwdog · #11 05-04-2011, 07:24 AM

Yes, K-140s are reversed as are the D-140s (IIRC).
It would still be prudent to check polarity with a battery to make sure. I would think that it's possible for a reconer to hook it up where red is positive, so I would definitely check any recone before installation.

Bassmec · #12 05-04-2011, 08:56 AM

Check polarity its easy to unscrew the red terminal and swap it for the black so its the same as a celestion seen this done several times.
The E140 was a very heavy old beast even heavier than the alnico D/K/140's, Yes I think you have an original new jbl cone kit fitted and yes its one of my favorite ever 15" bass sounds in the right cab.
And the e series where all the same spec, it was the fender signature D/120/130/140 jbl's that had quite different cones
for instance the D120f fitted to the fender pro reverb had a paper edge instead of a linen roll edge suspension.
I used to re-cone these things for a living, the only choice with an E series kit is the material of the voice coil cap.
Aluminum or paper, For bass guitar use I would choose Aluminum.
Love the tin can top end sound via a microphone
makes my strings sound slightly newer.

The cone date was written on the inside of the voice coil so you would have to strip the cone out to read it.
Glue a patch of breathable foam as a filter, to the hole in the magnet assembly you don't want any metal swarf
in your voice coil gap.

4Mal · #13 05-04-2011, 10:38 AM

Quote:

Originally Posted by coreyfyfe

Helpful:

http://www.jblpro.com/pub/technote/tn_v1n12b.pdf

Never knew that. I ran my E-140, reverse phase for some time then. I only ever ran one of those that way so I would never have noticed. When I ran multiple E140's, they were in the JBL Cabaret 4625 cabs so I expect they were wired correctly ...

coreyfyfe · #14 05-04-2011, 01:20 PM

Quote:

Originally Posted by 4Mal

Never knew that. I ran my E-140, reverse phase for some time then. I only ever ran one of those that way so I would never have noticed. When I ran multiple E140's, they were in the JBL Cabaret 4625 cabs so I expect they were wired correctly ...

I've been hesitant to run and extension with my B-15 for exactly this reason, I was never sure. I had looked it up before and saw it written on another forum that the D series were reversed but they had gone to standard nomenclature by the time the K series came around but could never substantiate that so I hadn't tried. After finding that and the info in this thread I'll definitely be checking mine to be sure.

BassGreaser · #15 05-04-2011, 02:03 PM

Quote:

Originally Posted by coreyfyfe

http://www.jblpro.com/pub/technote/tn_v1n12b.pdf

ok so my E-140 is a negative system.. what does that mean exactly

jnewmark · #16 05-04-2011, 03:17 PM

The way I'm reading that technote, when it was written, the E140 was a negative system, or " Currently at that time " However, the article does say that they would do a transfer over to positive in the coming years. Seems to me, that, depending on when the E140 was made, it could be either or. I would think that, if your E140 was made after the " orderly transition ", it would be positive. But, for some reason, JBL still did not label the terminals as such, even after the transition.

coreyfyfe · #17 05-04-2011, 05:17 PM

Quote:

Originally Posted by BassGreaser

ok so my E-140 is a negative system.. what does that mean exactly

I took that to mean it would be reverse polarity. Best to battery test them.

lbwdog · #18 05-04-2011, 05:33 PM

Quote:

Originally Posted by jnewmark

" However, the article does say that they would do a transfer over to positive in the coming years. Seems to me, that, depending on when the E140 was made, it could be either or. I would think that, if your E140 was made after the " orderly transition ", it would be positive. But, for some reason, JBL still did not label the terminals as such, even after the transition.

JBL TECH NOTE
"That is to say, no current models
will be changed to the new polarity convention during
their remaining catalog life"

I take that to mean that an E -140 would stay "negative" as long as that model is made.
Boy, they sure can confuse a chap....

jnewmark · #19 05-06-2011, 12:10 PM

Curiouser and curiouser. I've been wiring E140's backwards all these years, and noticed the cones moving outwards anyways ! Is there a device, other than the 9 volt battery thing, to check polarity ?

lbwdog · #20 05-09-2011, 06:10 AM

Quote:

Originally Posted by jnewmark

Curiouser and curiouser. I've been wiring E140's backwards all these years, and noticed the cones moving outwards anyways ! Is there a device, other than the 9 volt battery thing, to check polarity ?

I dunno. Maybe yours were positive polarity after all, but all I've seen were not (to the best of my recollection).

9V battery is the best way I can think of. I have experienced a sort of optical illusion before, when observing cone direction.
Depending on the lighting or angle, I've experienced a cone appearing to go forward when, upon closer inspection, it was really going backward.