LSiC crackle when playing pink noise

tn2036
tn2036 Posts: 16
in Troubleshooting
Picked up two LSi15's and a LSiC from CraigsList recently, powered by two Rotel amps I picked up earlier this year.

The center channel tweeter has a crackle. First noticed with movie audio. Tested with pink noise played through multiple amps, multiple channels, multiple connects, and multiple speaker wires. Definitely the speaker, and not the content or power system.

I don't think the tweeter is blown. I could test it in the other speakers. Fairly certain it's something in the crossover. Based on the known issues with resistors, I ordered new resistors to try first.

http://forum.polkaudio.com/discussion/162585/lsi15-tweeters-not-working#Comment_2064018

https://www.parts-express.com/mills-2-ohm-12w-non-inductive-resistor--005-2

They come in next week. Will post updates.

The LSi15s sound great. Dialed them in today.
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Comments

  • mlistens03
    mlistens03 Posts: 2,767
    tn2036 wrote: »
    Picked up two LSi15's and a LSiC from CraigsList recently, powered by two Rotel amps I picked up earlier this year.

    The center channel tweeter has a crackle. First noticed with movie audio. Tested with pink noise played through multiple amps, multiple channels, multiple connects, and multiple speaker wires. Definitely the speaker, and not the content or power system.

    I don't think the tweeter is blown. I could test it in the other speakers. Fairly certain it's something in the crossover. Based on the known issues with resistors, I ordered new resistors to try first.

    http://forum.polkaudio.com/discussion/162585/lsi15-tweeters-not-working#Comment_2064018

    https://www.parts-express.com/mills-2-ohm-12w-non-inductive-resistor--005-2

    They come in next week. Will post updates.

    The LSi15s sound great. Dialed them in today.

    good luck with the repair! The LSi series is awesome, and you will enjoy them.
    Micah
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  • F1nut
    F1nut Posts: 50,542
    It's not a resistor, you have a bad tweeter.
    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

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  • mlistens03
    mlistens03 Posts: 2,767
    edited June 2018
    F1nut wrote: »
    It's not a resistor, you have a bad tweeter.

    But he said he switched the tweeters around, and the noise stayed with the cabinet, not the tweeter. I thought the same as you when I first read the post, until I read that.
    Edit: oh you said you COULD, not you DID. In that case, it probably is the tweeters voice coil rubbing the side of the motor assembly.
    Micah
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  • tn2036
    tn2036 Posts: 16
    Thank you; Any ideas for a suitable aftermarket replacement? Just called Polk and they no longer have replacements in stock.
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  • mlistens03
    mlistens03 Posts: 2,767
    tn2036 wrote: »
    Thank you; Any ideas for a suitable aftermarket replacement? Just called Polk and they no longer have replacements in stock.

    I know peerless makes some ring radiator tweeters available on parts express, but I don’t think they will work without crossover modifications. I also don’t know if the new LSIM tweeters will work, but it seems unlikely.
    Look on eBay and similar sites to find used replacements.
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  • rooftop59
    rooftop59 Posts: 8,121
    tn2036 wrote: »
    I don't think the tweeter is blown. I could test it in the other speakers.

    he didn't actually test it in other speakers. Almost certainly the tweet. I know it sounds ridiculous, but if you got a really good deal I would just buy another center on ebay. Either sell the extra drivers or keep them as spares. Finding the proper replacement will be very difficult.

    Someone on the forum was selling a center really cheap. They might sell to you (some of us only sell to active members with 100+ posts, but that's entirely up to the seller).
    Living Room 2.2: Usher BE-718 "tiny dancers"; Dual DIY Dayton audio RSS210HF-4 Subs with Dayton SPA-250 amps; Arcam SA30; Musical Fidelity A308; Sony UBP-x1000es
    Game Room 5.1.4:     Denon AVR-X4200w; Sony UBP-x700; Definitive Technology Power Monitor 900 mains, CLR-3000 center, StudioMonitor 350 surrounds, ProMonitor 800 atmos x4; Sub - Monoprice Monolith 15in THX Ultra
    Bedroom 2.1     Harmon Kardon HK3490; Bluesounds Node N130; Polk RT25i; ACI Titan Subwoofer
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  • mlistens03
    mlistens03 Posts: 2,767
    @dbryant ?
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  • K_M
    K_M Posts: 1,629
    edited June 2018
    what is the going price of the Vifa/Lsi tweeter (used) now?

    I found one damaged on Ebay for $39.99, sounds a bit steep, for a damaged item.
    The brand new Vifa XT25tg30 is only like $32.00 on parts express.....
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  • rooftop59
    rooftop59 Posts: 8,121
    K_M wrote: »
    what is the going price of the Vifa/Lsi tweeter (used) now?

    I found one damaged on Ebay for $39.99, sounds a bit steep, for a damaged item.
    The brand new Vifa XT25tg30 is only like $32.00 on parts express.....

    Find one and let us know ;)
    Living Room 2.2: Usher BE-718 "tiny dancers"; Dual DIY Dayton audio RSS210HF-4 Subs with Dayton SPA-250 amps; Arcam SA30; Musical Fidelity A308; Sony UBP-x1000es
    Game Room 5.1.4:     Denon AVR-X4200w; Sony UBP-x700; Definitive Technology Power Monitor 900 mains, CLR-3000 center, StudioMonitor 350 surrounds, ProMonitor 800 atmos x4; Sub - Monoprice Monolith 15in THX Ultra
    Bedroom 2.1     Harmon Kardon HK3490; Bluesounds Node N130; Polk RT25i; ACI Titan Subwoofer
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  • mlistens03
    mlistens03 Posts: 2,767
    K_M wrote: »
    what is the going price of the Vifa/Lsi tweeter (used) now?

    I found one damaged on Ebay for $39.99, sounds a bit steep, for a damaged item.
    The brand new Vifa XT25tg30 is only like $32.00 on parts express.....

    But that isn’t the same tweeter. The Vifa tweeters used in the LSi series was better I believe.

    Also, doesn’t the LSi15 have a different impedance tweeter than the LSiC? Or is that just the midbass drivers? If so, then you have to make sure that I feel you buy one it isn’t from a LSi15.
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  • VR3
    VR3 Posts: 28,640
    Polk claims to alter the vifa tweeters, but they simply alter the faceplate, which can be swapped
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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  • K_M
    K_M Posts: 1,629
    edited June 2018
    mlistens03 wrote: »
    K_M wrote: »
    what is the going price of the Vifa/Lsi tweeter (used) now?

    I found one damaged on Ebay for $39.99, sounds a bit steep, for a damaged item.
    The brand new Vifa XT25tg30 is only like $32.00 on parts express.....

    But that isn’t the same tweeter. The Vifa tweeters used in the LSi series was better I believe.

    Also, doesn’t the LSi15 have a different impedance tweeter than the LSiC? Or is that just the midbass drivers? If so, then you have to make sure that I feel you buy one it isn’t from a LSi15.

    The lsiC and Lsi15 and all the lsi line use the same tweeter.
    The midbass drivers are wired in series in the Lsi15, and are slightly different in some minor ways, but if I remember correctly they were actually all 4 ohm drivers, but the impedance peak (and Qts) value was slightly different.

    In comparing both midbass drivers (we have several Lsi models) it was not apparent which was being used. So they are not all "that" different in reality.
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  • mlistens03
    mlistens03 Posts: 2,767
    K_M wrote: »
    mlistens03 wrote: »
    K_M wrote: »
    what is the going price of the Vifa/Lsi tweeter (used) now?

    I found one damaged on Ebay for $39.99, sounds a bit steep, for a damaged item.
    The brand new Vifa XT25tg30 is only like $32.00 on parts express.....

    But that isn’t the same tweeter. The Vifa tweeters used in the LSi series was better I believe.

    Also, doesn’t the LSi15 have a different impedance tweeter than the LSiC? Or is that just the midbass drivers? If so, then you have to make sure that I feel you buy one it isn’t from a LSi15.

    The lsiC and Lsi15 and all the lsi line use the same tweeter.
    The midbass drivers are wired in series in the Lsi15, and are slightly different in some minor ways, but if I remember correctly they were actually all 4 ohm drivers, but the impedance peak (and Qts) value was slightly different.

    In comparing both midbass drivers (we have several Lsi models) it was not apparent which was being used. So they are not all "that" different in reality.

    Ok, good to know.
    I had a terrible dream last night where I came upstairs and the cone in both midbass drivers had fallen out and was sitting on the ground, then the dog stepped on them and crushed them. Now I know that I can use the LSi15 drivers! :wink:
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  • mlistens03
    mlistens03 Posts: 2,767
    http://forum.polkaudio.com/discussion/181221/three-upgraded-lsic-speakers-with-one-having-a-rebuilt-high-end-crossover#latest
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  • mlistens03
    mlistens03 Posts: 2,767
    edited June 2018
    double Post...
    Post edited by mlistens03 on
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  • tn2036
    tn2036 Posts: 16
    Something like this...

    https://www.madisoundspeakerstore.com/ring-radiator-tweeters/vifa-xt25tg30-04-1-ring-radiator-tweeter/
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  • tn2036
    tn2036 Posts: 16
    on Parts Express...

    https://www.parts-express.com/peerless-by-tymphany-xt25tg30-04-1-dual-ring-radiator-tweeter--264-1016

    Many commenters / reviews indicating they use this as a replacement for the Polk LSi series

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  • mlistens03
    mlistens03 Posts: 2,767
    tn2036 wrote: »
    on Parts Express...

    https://www.parts-express.com/peerless-by-tymphany-xt25tg30-04-1-dual-ring-radiator-tweeter--264-1016

    Many commenters / reviews indicating they use this as a replacement for the Polk LSi series

    A lot of people do, but I believe it is a different tweeter, which means that it will sound different. It I should possible that it’s the same, but I doubt it.
    I would just contact @dbryant about his LSiC to see if he still has one left. If so, he has them priced as a steal at around $140, and then you will have every driver except for the tweeer should they go bad in any one of your other speakers.
    Micah
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