L100's, take down, parts and crossover (possible upgrading).

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ALL212
ALL212 Posts: 1,556
in DIY, Mods & Tweaks
'Tis the time of year that I've run out of fun things to do and I've been staring down the L100's and wondering what makes 'em tick... tock...

At the very least those nasty sandcast resistors gotta go as does that single electrolytic cap. Not much room in there, crossover just as wide as the woofer hole.

I'll be trying to reverse engineer the crossover.

So out came the tools.

Input wiring
8aur4f2yt5ip.jpg

Output wiring
4m2a1gbc43nj.jpg

The diapers
grqkpu2u17v1.jpg

Input cup - da back (anyone can find the front!)
b2pcjhc7undn.jpg

Tweeter front - there is a very thin film of foam that doesn't play well with disassembly. I'll need to find something to replace it.
0snlxyp1eh8j.jpg

Tweeter back
qdehjcbft6kf.jpg

Da woof
cxcb046xv4v4.jpg

Da woof back
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Bezels
cviapjf8uvfw.jpg

Cabinetry
hnogqxqjc3gx.jpg

Gigitty...crossover stuff
6g2q0bdxhbtw.jpg

back
8tx5lsug2b80.jpg

Image reversed to match the markings I've put there to reverse engineer this thing
50qgeey312ep.jpg












Aaron
Enabler Extraordinaire
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  • msg
    msg Posts: 9,434
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    Lol, the diapers
    I disabled signatures.
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  • mhardy6647
    mhardy6647 Posts: 33,032
    edited December 2021
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    ALL212 wrote: »
    'Tis the time of year that I've run out of fun things to do and I've been staring down the L100's and wondering what makes 'em tick... tock...

    At the very least those nasty sandcast resistors gotta go as does that single electrolytic cap. Not much room in there, crossover just as wide as the woofer hole.

    I'll be trying to reverse engineer the crossover.

    So out came the tools.
    .
    .
    .

    Input cup - da back (anyone can find the front!)
    b2pcjhc7undn.jpg

    .
    .
    .

    I mean... not to go all semantisist or anything -- but isn't that, technically, the front, and the... umm... back... is... you know, on the back. Of the speaker?

    B)

    ;)

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  • VR3
    VR3 Posts: 28,020
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    I would definitely replace the two iron core inductors in the main signal path of the midrange. The rest are parallel
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • ALL212
    ALL212 Posts: 1,556
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    VR3 wrote: »
    I would definitely replace the two iron core inductors in the main signal path of the midrange. The rest are parallel

    L4 and L3?

    I kinda have a working diagram now.

    Aaron
    Enabler Extraordinaire
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  • VR3
    VR3 Posts: 28,020
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    the two with the iron going over top are directly in line with the midrange
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • ALL212
    ALL212 Posts: 1,556
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    mhardy6647 wrote: »

    I mean... not to go all semantisist or anything -- but isn't that, technically, the front, and the... umm... back... is... you know, on the back. Of the speaker?

    B)

    ;)

    Why did I know as soon as I saw this post who it was! :D

    Aaron
    Enabler Extraordinaire
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  • ALL212
    ALL212 Posts: 1,556
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    The electrolytic is just part of a impedance resonance compensation circuit...maybe leave that. Explains why they "cheated" on a relatively small (11uf) cap.
    L5, C6, R6 for the woof
    L2, C3 R3 for the tweet

    those 6 components seem to be the same circuit, just for their corresponding driver.
    Aaron
    Enabler Extraordinaire
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  • SCompRacer
    SCompRacer Posts: 8,352
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    Technically speaking, isn't this a drawback? :D
    ALL212 wrote: »
    8tx5lsug2b80.jpg


    Salk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ * Signature Series Sonore Music Server w/Deux PS * Roon * Gustard R26 DAC / Singxer SU-6 DDC * Heavy Plinth Lenco L75 Idler Drive * AA MG-1 Linear Air Bearing Arm * AT33PTG/II & Denon 103R * Richard Gray 600S * NHT B-12d subs * GIK Acoustic Treatments * Sennheiser HD650 *
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  • pitdogg2
    pitdogg2 Posts: 24,559
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    Technically speaking yes....
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  • Clipdat
    Clipdat Posts: 12,599
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    When I read "impedance resonance compensation circuit" my eyes glaze over and I start mouth breathing.
    pnzJTq3.gif
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  • mhardy6647
    mhardy6647 Posts: 33,032
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    Clipdat wrote: »
    When I read "impedance resonance compensation circuit" my eyes glaze over and I start mouth breathing.
    pnzJTq3.gif
    You are the audiophile snake oil industry's kinda customer!
    :#
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  • SeleniumFalcon
    SeleniumFalcon Posts: 3,489
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    Quantum snake oil, please.
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  • VR3
    VR3 Posts: 28,020
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    I quantum charge and cryo freeze all of my gear
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • SCompRacer
    SCompRacer Posts: 8,352
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    What did one energized capacitor say to the other?

    I can hardly contain myself.
    Salk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ * Signature Series Sonore Music Server w/Deux PS * Roon * Gustard R26 DAC / Singxer SU-6 DDC * Heavy Plinth Lenco L75 Idler Drive * AA MG-1 Linear Air Bearing Arm * AT33PTG/II & Denon 103R * Richard Gray 600S * NHT B-12d subs * GIK Acoustic Treatments * Sennheiser HD650 *
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  • mhardy6647
    mhardy6647 Posts: 33,032
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    z0ofztbyu767.png

    5934vm6i0k3v.png

    https://dilbert.com/search_results?terms=dog+of+thunder
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  • ALL212
    ALL212 Posts: 1,556
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    Note: Tweeter bezel is held on with magnets.

    Complications: Can't get too crazy on crossover components. I have a 4.5" hole to work through and that's it. I suppose I could get the chainsaw out...cut the bottom off and do as I please, then just glue glob it all back together. :s Not like I'm getting any warranty work done on this. :#

    So da plan is to get rid of all sandcast resistors and the two ugliest inductors (L3, L4) and replace them with economical air core inductors. I might "tip" that electrolytic with some extremely small Sonicap capacitors left over from a Dahlquist toy. These are .0082uf ...yep, decimal is in the right spot. If nothing else I'll feel like I accomplished something there. Maybe...maybe replace C1 and C2 but size is of utmost importance here.

    Values of inductors:
    L1 - 0.12 mH, .3 ohm DCR but done in circuit as pulling even one lead is damn near impossible because it's glued down tight.
    L2 - 0.6 mH, .7 ohm DCR
    L3 - 0.5 mH, .2 ohm DCR
    L4 - 0.3 mH, .2 ohm DCR
    L5 - 3.6 mH, .7 ohm DCR

    There are some air core inductors over at parts express that are reasonably close in DCR.
    Probably use Mills resistors.

    Better ideas??
    Aaron
    Enabler Extraordinaire
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  • VR3
    VR3 Posts: 28,020
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    Check the mundorf L200 series Air core dcr. They were perfect for the l200
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • ALL212
    ALL212 Posts: 1,556
    edited December 2021
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    roughly this... and if Polk doesn't want it here it can obviously be removed.

    Things in the squares are being replaced...or attempted to be replaced on the same board. Gonna be squeaky tight!!


    Aaron
    Enabler Extraordinaire
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  • VR3
    VR3 Posts: 28,020
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    I wouldn't recommend posting current production schematics
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • ALL212
    ALL212 Posts: 1,556
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    what schematic... B)
    Aaron
    Enabler Extraordinaire
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  • VR3
    VR3 Posts: 28,020
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    Yeah, Polk is really awesome to let us openly mod their products and talk about what all we do.... Not many manufactures are down with that
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • ALL212
    ALL212 Posts: 1,556
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    Edit on the inductor values

    L3 is .6 not .5

    Values are written on the board but covered by the component.
    Aaron
    Enabler Extraordinaire
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  • ALL212
    ALL212 Posts: 1,556
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    And done! Still sound good in spite of my work. :#

    gsn8ps3cl8st.jpeg
    clbzao4jrgt9.jpeg
    Aaron
    Enabler Extraordinaire
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  • Clipdat
    Clipdat Posts: 12,599
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    What's the first track you're gonna play through them after hot cross buns?
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  • ALL212
    ALL212 Posts: 1,556
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    Gangnam style I think…
    Aaron
    Enabler Extraordinaire
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  • Clipdat
    Clipdat Posts: 12,599
    edited February 2022
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    Nice! Then maybe after that go way back to some Who Let The Dogs Out and maybe even Macarena (bayside boys mix, of course)

    https://www.youtube.com/watch?v=zWaymcVmJ-A
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  • ALL212
    ALL212 Posts: 1,556
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    I’ll have to get out my reference level K-tell records and see how those play. Unless I can find my 8-track player…
    Aaron
    Enabler Extraordinaire
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  • VR3
    VR3 Posts: 28,020
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    Baby shark
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • Clipdat
    Clipdat Posts: 12,599
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    Don't act like you haven't played that on the Grandes!
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  • VR3
    VR3 Posts: 28,020
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    Oh you know it
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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