4430 polarity .....again!

[davidpou]

I know this has been discussed but I still find it confusing. can anyone be kind enough to give me the last word on this issue please?

The tech sheet of the 4430 is saying: green to the red terminal of the 2235H and green and black cable to the black terminal, and for the 2425H yellow to the red terminal and yellow and black to the black terminal.
Do you confirm ?

as for the speaker terminal: should i input the plus of my amp into the red terminal or to the black ?

thanks

[hjames]

I know this has been discussed but I still find it confusing. can anyone be kind enough to give me the last word on this issue please?

The tech sheet of the 4430 is saying: green to the red terminal of the 2235H and green and black cable to the black terminal, and for the 2425H yellow to the red terminal and yellow and black to the black terminal.
Do you confirm ?

as for the speaker terminal: should i input the plus of my amp into the red terminal or to the black ?

thanks

I would confirm the JBL internal crossover color coding.

Do you have any other speakers running in the room at the same time, or is that pair it?

If that is the only pair: Amp + to Red on the speaker, Amp - to Black on the speaker.

[davidpou]

I would confirm the JBL internal crossover color coding.

Do you have any other speakers running in the room at the same time, or is that pair it?

If that is the only pair: Amp + to Red on the speaker, Amp - to Black on the speaker.

Thanks for the fast answer. So if you are right, I am... cause I did just this...

The thing is I just boyght these speakers, the 2235H have been refoamed by previous owner just before selling. And I wanted to check the impedances of both the drivers and the woofers (which are just fine by the way). And I realised that the green and black cable was on the red terminal of the 2235H. So I came back to the TS ans saw it was wrong... so I inversed them and I do find now that I have less bass... :crying:
I read that both 2235H and 2425H are negative, that JBL has inverted coding....so I come back to LH...

PS I am mono amping from a MC275 (with the passive internal crossover) so may be I got the correct bass it s just the amp that doesn't have enough power....to drive the 2235H... I don't know

[hjames]

Thanks for the fast answer. So if you are right, I am... cause I did just this...

The thing is I just bought these speakers, the 2235H have been refoamed by previous owner just before selling.
And I wanted to check the impedances of both the drivers and the woofers (which are just fine by the way).
And I realized that the green and black cable was on the red terminal of the 2235H.
So I came back to the TS and saw it was wrong... so I inverted them and I do find now that I have less bass... :crying:
I read that both 2235H and 2425H are negative, that JBL has inverted coding....so I come back to LH...

PS I am mono amping from a MC275 (with the passive internal crossover) so may be I got the correct bass
it s just the amp that doesn't have enough power....to drive the 2235H... I don't know

I have refoamed 2235 speakers before and replacing the surrounds should have no effect on the phase of the driver -
but whether the previous owner of your drivers changed something else in the process, I can not say.

I would check it against the Crossover chart and match that to your particular speakers -
but if you have less or muddier bass bass when you use the "factory" connections, and its
sounds better when you reverse the polarity ...
well, you do have to trust your ears as none of us are there.

[rusty jefferson]

..... And I realised that the green and black cable was on the red terminal of the 2235H. So I came back to the TS ans saw it was wrong... so I inversed them and I do find now that I have less bass... :crying:
I read that both 2235H and 2425H are negative, that JBL has inverted coding....so I come back to LH...

I would have to assume (tho I know better) these speakers would excurt the woofers "out" with a positive battery voltage applied to the red binding posts on the cabinets. Wire the woofers internally per the schematic (grn to red and grn/blk to black) and then confirm both woofers do in fact move out with the battery test. If you have subwoofer(s), be sure they are in phase (which could be inverted) with the 4430s after the battery test.

If your preamp doesn't invert phase (your amps don't), then red on the amps to red on the speakers. If the preamp does invert phase, then red on the amps to black on the speakers.



PS I am mono amping from a MC275 (with the passive internal crossover) so may be I got the correct bass it s just the amp that doesn't have enough power....to drive the 2235H... I don't know


I would imagine just 1 of those amps would have plenty of power, imo. However, I don't think they are known for prodigious amounts of bass. You may get "better" bass from a different tap on the amp(s), or different output tubes.

[davidpou]

I have refoamed 2235 speakers before and replacing the surrounds should have no effect on the phase of the driver -
but whether the previous owner of your drivers changed something else in the process, I can not say.

I would check it against the Crossover chart and match that to your particular speakers -
but if you have less or muddier bass bass when you use the "factory" connections, and its
sounds better when you reverse the polarity ...
well, you do have to trust your ears as none of us are there.

I am not saying that refoaming in itself could have changed something, I just mentioned it because the tech who did the job had to undo the cables from the 2235H and I do not know if his inversion (from the TS indications) is intentionnal or not.... I do not expect previous owner to have touched the filter, this is something I do not want to consider now.
I do not know what are the "factory connections" ... I just reversed on the 2235H... logically I woud have to reverse the drivers aswell since they are both negative (in term of polarisation) and need to be in phase. I will do a test with and without the drivers reversed.... and let you know....later in the day....

[davidpou]

I finally got back to TS specifications in terms of colour .... I had not that much more bass in reversing the phase after all... I found forumers here in France saying that the manual was right. I guess I got quickly accustomed to these new speakers, and I forgot in one week the poor bass response I had with the 4312 or even L 101....
One tends to get used very quicly to good things and consider it "standard" shortly then after....
still I have to go bi amping to improve my bass response, and I have enough time and money cut the boomer at 500 Hz or so and insert a 2123H in between....

[remusr]

You should have plenty of bass with the 2235H in the 4430. Wiring the drivers per the tech bulletin as you have done will be correct.
Regarding biamping, which owes its sonic "advantage" primarily to allowing the owner to control the amount of power going to each driver, similar to what you do when you add a subwoofer. Thereby giving the listener the ability to deviate from how the passive crossover tuned the output from each driver.
As long as both woofers are wired the same so they are in phase as you apparently did, switching the leads cannot alter your bass quantity. Out of phase waves cancel so it could be the room and your listening position in it that have regions of resonances/reinforcements/reflections with accompanying perceived loss of bass or treble or clarity or whatever. If the crossover has healthy components - no shorts or opens -the crossover to the mid/hi is well out of the bass region so interaction between the drivers in each speaker will have no effect on the system's bass. Tube amps as your MC275 have less damping, or control over the driver's cone, than solidstate amps so may sound less bass'y - could that be your issue?
I wouldn't add a midrange driver unless you find directivity issues in your room with the woofer beaming a bit below its crossover. The big fault with the 4430 is lack of dispersed highs, but most listeners on this forum are mature enough they cannot hear much over 10-13k anyways.

[Retroman]

I owned a new pair of 4430s' in 1995. I put them in the same room positions I previously had my 250Ti and XPL200s. The power amp was a Threshold SA4e--tons of bass impact and control. I found their bottom-end underwhelming and top-end soft and lacking in detail and extension. They sure played loud but did not equal the higher level of performance of the 250Tis. Surprisingly, their bass was not much better than the XPL200. Consequently, I sold them after several months.

[hjames]

LOTS of good info in this thread over at AK, including a copy of the factory Schematic in the first post!!

Cheap and (Pretty) Easy JBL 4430 Upgrade

http://www.audiokarma.org/forums/showthread.php?t=537606

[audiomagnate]

I am not saying that refoaming in itself could have changed something, I just mentioned it because the tech who did the job had to undo the cables from the 2235H and I do not know if his inversion (from the TS indications) is intentionnal or not.... I do not expect previous owner to have touched the filter, this is something I do not want to consider now.
I do not know what are the "factory connections" ... I just reversed on the 2235H... logically I woud have to reverse the drivers aswell since they are both negative (in term of polarisation) and need to be in phase. I will do a test with and without the drivers reversed.... and let you know....later in the day....
You do know that for lots of older JBL drivers the black terminal is the same as a + terminal on a non JBL speaker, right? It reminds me of older BMW's with their turn signal stalks on the "wrong" side.

[davidpou]

You should have plenty of bass with the 2235H in the 4430. Wiring the drivers per the tech bulletin as you have done will be correct.
Regarding biamping, which owes its sonic "advantage" primarily to allowing the owner to control the amount of power going to each driver, similar to what you do when you add a subwoofer. Thereby giving the listener the ability to deviate from how the passive crossover tuned the output from each driver.
As long as both woofers are wired the same so they are in phase as you apparently did, switching the leads cannot alter your bass quantity. Out of phase waves cancel so it could be the room and your listening position in it that have regions of resonances/reinforcements/reflections with accompanying perceived loss of bass or treble or clarity or whatever. If the crossover has healthy components - no shorts or opens -the crossover to the mid/hi is well out of the bass region so interaction between the drivers in each speaker will have no effect on the system's bass. Tube amps as your MC275 have less damping, or control over the driver's cone, than solidstate amps so may sound less bass'y - could that be your issue?
I wouldn't add a midrange driver unless you find directivity issues in your room with the woofer beaming a bit below its crossover. The big fault with the 4430 is lack of dispersed highs, but most listeners on this forum are mature enough they cannot hear much over 10-13k anyways.

thanks for all this.
I put them on 18 cm concrete and see a better bass response... I also reinforced the bass on the C22.... And I can say for a flat it is more than OK.
after gavering info here in France a good solution for bi amping would be the Phase linear 400 for the 2235H and the 275 for the mids and highs with a DCX2496, so WITH the double conversion I wanted to avoid.... its a grand in euros so not that much.... I would need a tech to put this in place and mesure and correct the response curve.... which I won't be able to do by my self.... But its been only two weeks I have them so for the time being i still rediscover my music.... if you have an alternative to this set up please let me know.

[macaroonie]

Sounds like you are on the right track there David. Glad you got sorted out.
Be sure that the Phase Linear is in tip top shape , they are known to fail and when they do they take out the drivers.

[davidpou]

Sounds like you are on the right track there David. Glad you got sorted out.
Be sure that the Phase Linear is in tip top shape , they are known to fail and when they do they take out the drivers.

yes ! so I have been told. Apparently we have a Phase linear specialist in France called "Limas" http://www.atlantic-audio-vintage.fr/contact.html

Apparently the PL 400 beats every opponent when it comes to bass, including yamaha PS 2500 or 3500 etc...its value is 800 €.....

the right track (10 months I was looking for it! they are one owner and a sort of 9 or 8.5 /10 on audiogon scale).... and well, a classical track!.... you know the story: a pair of 4312A,... then some very vintagy L101... then the 4430.... after that one cannot stop it ...L300....4344... but nowadays there is the M2....! so I still have plenty to dream of....