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Thread: Quick & Dirty 4430-Inspired Two-Ways Part I

  1. #376
    RIP 2011 Zilch's Avatar
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    Quote from another thread:

    "Given the room finishes I would steer away from the 4430 bi radial unless you propose to damp the walls.

    The wash off these monitors will overpower the direct radiated sound to your ears otherwise."

    Certainly early reflections can be a problem with wide-field biradials in a "live" listening environment, though JBL touted this as a desireable feature in monitoring installations. It has not been a problem in my garage, apparently because there's so much other "stuff" in there. Note that the 4430's controlled 100° horizontal field is already somewhat narrower than that provided by the dispersion lenses of earlier monitors. Everything in context.

    Edit: On this subject, from the Project Everest White Paper:

    "Some loudspeakers which have a wide radiation pattern tend to produce a rather "spacey" sound, inasmuch as they may bring into play considerable local room reflections. Many listeners at non-center positions mistake this for cues in the recording itself, and such loudspeakers give the impression of richness in ambience, but of course without precision of localization."

    We earlier discussed the availability of dispersion patterns other than the 4430's 100° X 100° in Progressive Transition waveguides which might serve to satisfy those who prefer a narrower field. They're available in 100° X 100°, 90° X 50°, 70° X 70°, and 60° X 40° versions, in both square and compact rectangular (my preference) format.

    Here's the PT-F64HF, the 60° X 40° version, shown also in comparison the PT-F1010HF (right) which I am presently using. It's quite solidly molded, heavy even. Note the difference in depth between the two versions. Time alignment might be more akin to 4430 standard, though that would have to be confirmed with testing.

    K2-S9800 and Project May use a 90° X 40° horn (correct me if I'm wrong, please). Apparently JBL has never produced a compact PT-F version other than prototypes in that pattern (no current products use it), but a square PT-H95HF 90° X 50° is available for those who might prefer controlled vertical dispersion and reduced early ceiling/floor reflections. 4430's identical 100° horizontal beamwidth for both LF and HF drivers at crossover seamlessly melds the system into one source, according to JBL design....
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  2. #377
    RIP 2011 Zilch's Avatar
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    Also available is the 1" thread-on SF horn used in AC2215/95:

    http://www.jblproservice.com/pdf/AE%...2215,95-WH.pdf

    It's really "plastic" in comparison the PT waveguides, without even a metal threaded insert such as the OASR horn has, but it's also really cheap at $9.90.

    Worth a shot for those wanting to experiment with the 90° X 50° pattern using smaller drivers like the 2418H-1 shown here. I haven't played them yet, but I'm bettin' they're gonna require a generous slather of damping material on the back:
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  3. #378
    Senior Member Guido's Avatar
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    Today I released my PT Waveguides from the customs. Wasn't really a problem

    Thank you so much Zilch!

    I like these Horns! Ralf and myself will test them soon with 2426's in his 4430 clones.
    As written before I have to wait with the 2431 drivers.

  4. #379
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    Good DEAL, Guido!

    They're gonna play too "hot" in the 8 - 10 kHz range, so you'll need some EQ until you get your 2431H's and the AM crossovers running.

    We're eager to hear how you like them in action....

    [Butt-cheeks suddenly become flat-ass!]

  5. #380
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    Zilch,

    Excellent summary above.

    I will have to consult your expertise on a new prototype system when I clear my project bench.

    Ian

  6. #381
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    DIY 4430 (N3134) crossovers complete including "Biwire" option:

    http://audioheritage.org/vbulletin/s...2926#post52926

    [Zilchster will listen now.... ]

  7. #382
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    The tale of "Three Crossovers"

    RTA measurements of three crossovers:

    1) Factory N3134 (4430, left)

    2) DIY N3134 (details in above-linked thread)

    3) DIY N200T3 (right, discussed earlier here)



    The "Objets d' arse" they're measured on:

    1) B380

    2) 2344A

    3) 2427H with 2426 throat adapter


    Each of the three run full range on a single JBL 6260 amp, i.e., not biamped.
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    Last edited by Zilch; 05-05-2005 at 12:43 AM. Reason: Stupid indent doesn't work worth a crap here....

  8. #383
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    1) N200T3 presented first for proximal comparison to factory crossover results
    2) Factory crossover at "0" setting
    3) Factory crossover at max flat setting for this room
    4) DIY N3134+ before inductor tuning (stock values per parts list)
    5) DIY N3134+ after inductor tuning and set max flat also (values per schematic)
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  9. #384
    RIP 2011 Zilch's Avatar
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    How do the new DIY versions sound?

    Cleaner, crisper, brighter, even "sibilent" in comparison to factory stock crossovers.

    Same thing I said about N200T3's earlier.

    I've built 4 DIY crossovers now, and I'm starting to think this "signature" is characteristic of Dayton metalized polypropylene capacitors bypassed with Theta film-and-foils. They all sound like this.

    The response curves are quite good, as may be seen above. They were less bright before retuning the inductors to schematic values....

  10. #385
    Senior Member Guido's Avatar
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    Respect!

    Which inductors did you retune?

  11. #386
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    Quote Originally Posted by Zilch
    "sibilent"
    Really?

    adj.
    Of, characterized by, or producing a hissing sound like that of (s) or (sh): the sibilant consonants; a sibilant bird call.
    n.
    A sibilant speech sound, such as English (s), (sh), (z), or (zh).

    See if they need to play for a few days...

    ***

    Ah! I forgot you aren't running them biased...

  12. #387
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    Quote Originally Posted by Guido
    Which inductors did you retune?
    Hi, Guido!

    Nothing special, I just brought all three to N3134 schematic spec. Gonna put that over in the construction thread.

    Quote Originally Posted by Giskard
    Really?
    I don't know how else to express it. The vocalists' consonants have more sibilence on these, without being "harsh."

    Remember also, this is a garage listening room, tho Widget can attest it's not as "live" as might be expected.

    For the first time ever, I was also shocked to hear the separate notes of mandolin string pairs resolved distinctly.

    [Gonna listen to that again today to be sure I wasn't imagining it.... ]

  13. #388
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    Interesting observation Zilch...

    Like an extra dimension of breath? "Breathiness"

    How about: Forced vocalization, as in hearing the process of sibelant sound forming? If you think about it, there are specific air movements that create the ability of one to produce those consonants.

    I suppose- extra details if you boil it down to the minimal expression.

    Then again, it could just be a hiss from the snake trapped in your box...

  14. #389
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    Quote Originally Posted by Giskard
    Ah! I forgot you aren't running them biased...
    Yeah, that's the next crossover project, most likely. I didn't want to take big leaps here.

    It may also be that's just how these combos play with titanium diaphragms, tho I'm not gonna assert that on the basis of this limited experience....

  15. #390
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    Quote Originally Posted by Zilch
    It may also be that's just how these combos play with titanium diaphragms
    Could be... I've only tried that combo with direct radiators.

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