Handy guide to the "proper" juxtaposition of inductors in crossovers

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Comments

  • agfrost
    agfrost Posts: 2,421
    What is "bad" might be somewhat nebulous, but this document agrees that arrangements 6 & 7 are "good".
    Jay
    SDA 2BTL * Musical Fidelity A5cr amp * Oppo BDP-93 * Modded Adcom GDA-600 DAC * Rythmik F8 (x2)
    Micro Seiki DQ-50 * Hagerman Cornet 2 Phono * A hodgepodge of cabling * Belkin PF60
    Preamp rotation: Krell KSL (SCompRacer recapped) * Manley Shrimp * PS Audio 5.0
  • mhardy6647
    mhardy6647 Posts: 32,926
    edited September 2018
    so... listen... I would still argue the JPG's handy in that it is small and has a lot of info on it. As to how accurate it may (or may not be) -- note that I did put "proper" in double quotes, folks! :)

    Just think before you stack inductors, 'K?
    And avoid them iron/ferrite/etc. core jobbies like the plague.

    sheesh, tough crowd. I'm tellin' ya...

    giphy.gif

    ;)
  • gmcman
    gmcman Posts: 1,739
    edited September 2018
    delkal wrote: »
    Lets just say this is not a handy guide. It is either wrong with number 4 being very bad or that a lot of people can't understand the difference between number 4 and number 6.

    I think it is a handy guide, but again, I just wanted to clarify my way of looking at this so you dont think I'm crazy.... B)

    Safe bet #4 is being viewed from the top, with the left coil laying flat. However, my point is, that's not 100% distinguishable.

    When I said to imagine viewing from the side....this is what I meant...looking at it from this angle, the left coil wouldn't be flat.

    Forgive my artistic inabilities..lol...but here's a quick cut & paste....#4 from the side.

    4qf83rsdc7vz.jpg


  • agfrost
    agfrost Posts: 2,421
    Your pictures are prettier than mine. :)
    Jay
    SDA 2BTL * Musical Fidelity A5cr amp * Oppo BDP-93 * Modded Adcom GDA-600 DAC * Rythmik F8 (x2)
    Micro Seiki DQ-50 * Hagerman Cornet 2 Phono * A hodgepodge of cabling * Belkin PF60
    Preamp rotation: Krell KSL (SCompRacer recapped) * Manley Shrimp * PS Audio 5.0
  • mhardy6647
    mhardy6647 Posts: 32,926
    gmcman wrote: »
    ...
    Forgive my artistic inabilities..lol...but here's a quick cut & paste....#4 from the side.

    4qf83rsdc7vz.jpg


    does that say "OH"?

    ;)
  • gmcman
    gmcman Posts: 1,739
    mhardy6647 wrote: »
    gmcman wrote: »
    ...
    Forgive my artistic inabilities..lol...but here's a quick cut & paste....#4 from the side.

    4qf83rsdc7vz.jpg


    does that say "OH"?

    ;)

    Well.....depends on what side you look at it from...lol :p

  • mhardy6647
    mhardy6647 Posts: 32,926
    Apropos of this thread -- I just happened to notice this bespoke XO layout from one of the Flikr accounts which I 'follow'...

    ahpbuvsxcap5.png

    :)

    source: https://flic.kr/p/28ubbyh

    Apparently this is a JBL "4301b" build/rebuild.
    https://flic.kr/s/aHsmsysHbF

    http://www.jblpro.com/pub/obsolete/4301b.pdf
  • delkal
    delkal Posts: 764
    agfrost wrote: »
    delkal wrote: »
    Lets just say this is not a handy guide. It is either wrong with number 4 being very bad or that a lot of people can't understand the difference between number 4 and number 6.

    Care to illuminate us as to who comprises "a lot of people?"

    You are one but NOT the only one. The table is confusing. I didn't go back and count but a number of people say the photographed inductors are OK. But according to the table they are very bad. One of them is wrong

    Here is my even worse attempt to show it. Your diagram is on the left, The table number 4 is on the right. They are the same. This is different from the T configuration the table claims is good.

    8sngotpwbobo.png


  • delkal
    delkal Posts: 764
    mhardy6647 wrote: »
    Apropos of this thread -- I just happened to notice this bespoke XO layout from one of the Flikr accounts which I 'follow'...

    ahpbuvsxcap5.png

    :)

    source: https://flic.kr/p/28ubbyh

    Apparently this is a JBL "4301b" build/rebuild.
    https://flic.kr/s/aHsmsysHbF

    http://www.jblpro.com/pub/obsolete/4301b.pdf

    This is the number six (so good) and with the distance it is very good.......

    In fact that is the sexiest crossover I have ever seen! All I can say is Wow and Bravo!
  • mhardy6647
    mhardy6647 Posts: 32,926
    delkal wrote: »
    ...In fact that is the sexiest crossover I have ever seen! All I can say is Wow and Bravo!

    If so -- you apparently don't get out much :) There's a thread of bespoke XOs here at the Polk Forums someplace that even gives me pause.

    The layout is -- interesting. Plenty of space between inductors, so probably not at all problematic. As in aviation -- spacing is your friend :)
  • mhardy6647
    mhardy6647 Posts: 32,926
    edited September 2018
    BTW, I've resisted posting photos of my current XOs in the context of this thread mostly because each one only contains one inductor each. :p As such the two inductors in the stereo pair of XOs are about... umm... 12 feet apart. :|

    They're also not particularly attractive, nor even terribly impressive -- nice Goertz foil inductors, tho' :)
  • verb
    verb Posts: 10,176
    Gotta laugh here professor! Your students are getting a bit, unruly! :smile:
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  • F1nut
    F1nut Posts: 49,708
    edited September 2018
    delkal wrote: »
    mhardy6647 wrote: »
    Apropos of this thread -- I just happened to notice this bespoke XO layout from one of the Flikr accounts which I 'follow'...

    ahpbuvsxcap5.png

    :)

    source: https://flic.kr/p/28ubbyh

    Apparently this is a JBL "4301b" build/rebuild.
    https://flic.kr/s/aHsmsysHbF

    http://www.jblpro.com/pub/obsolete/4301b.pdf

    This is the number six (so good) and with the distance it is very good.......

    In fact that is the sexiest crossover I have ever seen! All I can say is Wow and Bravo!

    While a clean layout I've seen way more impressive. I really don’t like the solder work, which reminds me of butt joints in wood working, which are weak and do not last.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • agfrost
    agfrost Posts: 2,421
    delkal wrote: »
    agfrost wrote: »
    delkal wrote: »
    Lets just say this is not a handy guide. It is either wrong with number 4 being very bad or that a lot of people can't understand the difference between number 4 and number 6.

    Care to illuminate us as to who comprises "a lot of people?"

    You are one but NOT the only one. The table is confusing. I didn't go back and count but a number of people say the photographed inductors are OK. But according to the table they are very bad. One of them is wrong

    Here is my even worse attempt to show it. Your diagram is on the left, The table number 4 is on the right. They are the same. This is different from the T configuration the table claims is good.

    8sngotpwbobo.png


    I fully agree that both are different from the 'good' T one. My observation is that the sketch for #4 could be be the | __ shape or the |––. These two shapes are both a) similar and b) distinct! The vertical orientation on the SDA board yields the T shaped one; having one coil flat on the board as in the custom crossover gmcman posted. Looking more carefully at the factory SDA crossover, there doesn't appear to be a difference between the T and L comformation due to the fact that the height of the coil is roughly the width of the coil. This differs from the aftermarket inductor, whose height>>its width.

    Anywho, that's where I'm differentiating between the two versions. Is it an important differentiation? I've no idea as I haven't played with crossover design in this fashion. Feel like I should break out on of DarqueKnight's old phrases: "In the future, when I am more dedicated to audio...."

    Peace.
    Jay
    SDA 2BTL * Musical Fidelity A5cr amp * Oppo BDP-93 * Modded Adcom GDA-600 DAC * Rythmik F8 (x2)
    Micro Seiki DQ-50 * Hagerman Cornet 2 Phono * A hodgepodge of cabling * Belkin PF60
    Preamp rotation: Krell KSL (SCompRacer recapped) * Manley Shrimp * PS Audio 5.0
  • mhardy6647
    mhardy6647 Posts: 32,926
    just put the inductors on opposite ends of the XO board and sleep well at night ;)