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Thread: Woofers, reconed vs. stock condition: Differences in sound & power handling?

  1. #41
    ff Fortissimo toodles's Avatar
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    Quote Originally Posted by David Anderson View Post
    ...The reason I said don't kill the messenger is because now someone will come along an argue that given the shifting phase relationship in the crossover region due to the moving sound source, driver phase makes no difference in a Leslie. I will not venture an opinion on that.
    I would say it does make a difference. The Leslie motion isn't always on, and the phase difference is relative to the spacing between the sound sources. Better to have the two sources in phase.

  2. #42
    pp Pianissimo andyhof's Avatar
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    Quote Originally Posted by toodles View Post
    I would say it does make a difference. The Leslie motion isn't always on, and the phase difference is relative to the spacing between the sound sources. Better to have the two sources in phase.
    So, Don Leslie set things up to reverse polarity on one driver since there's a 2nd order dividing network. But why did he choose the woofer and not the compression driver?


    I am going to experiment... but before i do... curious if anyone's noticed any kind of difference to wire woofer (+) to (+) and compression driver (+) to (-) rather than woofer (+) to (-) and compression driver (+) to (+) ?
    Last edited by andyhof; 11-15-2017 at 04:17 AM. Reason: grammar

  3. #43
    mf Mezzo-Forte MihevicB3's Avatar
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    Quote Originally Posted by David Anderson View Post
    , , , Leslie flipped the woofer. . . .
    I would have expected the woofer to be normal and the treble to have been flipped since phase difference between tone cabinets is more noticeable at the lower frequencies and this would pose a problem between a Leslie cabinet and a Hammond cabinet next to each other. If the wiring polarity convention is followed from the preamp output of the console to the final output to the speakers, the tone cabinets should be in phase. I always check a low pedal frequency to be sure the cabinets are in phase. If they are out of phase, I flip the leads at the output of the Leslie 1:1 isolation transformer.

    In the early days, Don Leslie and Mr. Hammond didnít get along very well. Maybe Don did it on purpose hoping that his Leslie would overpower the Hammond cabinet at the lower frequencies.

    John M.
    1956 Hammond B3
    1963 Leslie 122
    Two Pr40ís
    One JR-20 (for fluid reverb signal)
    Hamptone LEQ3B
    Trek II Reverb
    Trek II String Bass

  4. #44
    fff Fortississimo David Anderson's Avatar
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    1 members found this post helpful.
    Quote Originally Posted by MihevicB3 View Post
    In the early days, Don Leslie and Mr. Hammond didn’t get along very well. Maybe Don did it on purpose hoping that his Leslie would overpower the Hammond cabinet at the lower frequencies.
    Sometimes, things are simply done unintentionally. Earlier 6H Leslies with extra cabinet sockets are out of phase with later cabinets with one input connector and slow motor outlets because they took the amp input from the additional speaker socket in earlier models. Sal Azzarelli noticed this and mentioned it to Don Leslie who admitted that this was simply something they never thought about.

    So a 22H cabinet will be out of phase with a 122, everything else being stock.

    Having the lower drum turn in the opposite direction from the horn was also reportedly an unintentional result of having to flip the lower motor stack to make room for the slow motor.
    I'm David. 'Dave' is someone else's name.

  5. #45
    pp Pianissimo Bradley's Avatar
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    All these mistakes and oversights - and yet...

  6. #46
    fff Fortississimo David Anderson's Avatar
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    Quote Originally Posted by Bradley View Post
    All these mistakes and oversights - and yet...
    I wasn't intending to diminish the legacy, only to point out that it's an error in thinking to assume that every design decision was completely thought-out in all its potential ramifications.
    I'm David. 'Dave' is someone else's name.

  7. #47
    pp Pianissimo Bradley's Avatar
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    Quote Originally Posted by David Anderson View Post
    I wasn't intending to diminish the legacy, only to point out that it's an error in thinking to assume that every design decision was completely thought-out in all its potential ramifications.
    I hope I wasn't perceived as implying such. Had I had one, I would have attached a tongue-in-cheek emoji.

  8. #48
    pp Pianissimo andyhof's Avatar
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    Alright, so here's the V21 from my 145 cabinet. Stock.
    red dot marking (+) terminal clearly marked.
    then the green goes inside and switches with the black.
    The woofer has been swapped out over the years but this V21 has been here.

    My JBL d140f woofer is connected green (out of dividing network) to black JBL woofer terminal.... black (out of dividing network) to red JBL woofer terminal. But these old JBL's have negative polarity (red=neg black=pos) meaning this JBL d140f is wired positive polarity from the dividing network.

    So in this case, the V21 is wired ~180 degrees from the woofer.

    Ya think it's safe to say that either the V21 or the woofer were connected out of phase based on the mood, or the week, or the year of production?

    I'm just gonna use a polarity checker cause this stuff is driving me crazy
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    Last edited by andyhof; 11-16-2017 at 06:17 PM.

  9. #49
    ppp Pianississmo dboomer's Avatar
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    The horn is spinning. What do you imagine happens to the phase relationship when the sound source is moving?

    Since they didnt have FFT analysis back when this was developed they just guessed. But “electrical” phase relationship is never much of a concern anyway. It’s “acoustical” phase that matters, well if you are looking for perfect reproduction, so all bets are off.

    Btw... it doesnt matter which of the pair are flipped since what you are concerned with is the relationship. So stop stressing and go back to playing.

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