Lsi15 tweeters not working

alexio
alexio Posts: 5
edited July 2014 in Troubleshooting
hello,

I'm used to being knowledgeable and helpful on forums, but in the electronics/audio arena I am a complete ignoramus... so my apology for a "dumb" question.

I have two Lsi15 towers and and an LsiC center... had been running these at very moderate volume on a $500 yamaha receiver (not sure of model as I don't have it anymore).. I mostly watched movies and listened to low volume music as I live in a condo complex.

My tweeters however have stopped working... I changed out the receiver to another yamaha one which has 140W x 5 channels, and still no tweeters. I looked at the crossovers and there are no visible burn signs or physical damage, and also switched in my lsiC tweeter to see if my actual tweeters were blown.. but when I put my functioning tweeter in the towers there was still no signal.

does any forum member have suggestions for me?

thank you.
Post edited by alexio on

Comments

  • Dennis Gardner
    Dennis Gardner Posts: 4,860
    edited July 2014
    Try the 15's tweeters in your center speaker. That is the easiest way to test. Make sure your brass jumpers are in place on the binding posts on the 15s.
    HT Optoma HD25 LV on 80" DIY Screen, Anthem MRX 300 Receiver, Pioneer Elite BDP 51FD Polk CS350LS, Polk SDA1C, Polk FX300, Polk RT55, Dual EBS Adire Shiva 320watt tuned to 17hz, ICs-DIY Twisted Prs, Speaker-Raymond Cable

    2 Channel Thorens TD 318 Grado ZF1, SACD/CD Marantz 8260, Soundstream/Krell DAC1, Audio Mirror PP1, Odyssey Stratos, ADS L-1290, ICs-DIY Twisted , Speaker-Raymond Cable
  • alexio
    alexio Posts: 5
    edited July 2014
    Try the 15's tweeters in your center speaker. That is the easiest way to test. Make sure your brass jumpers are in place on the binding posts on the 15s.

    that's what I tried... I took the tweeter out of the center and put into the towers... while the actual unit worked while in the center speaker, once i put it into either of the towers it stopped working... so it's something about the signal which goes to the tweeters in the towers which is the issue.

    the gold bridges are in place, but I also tried removing them and plugging in separate wires for the top black and red plugs... still nothing from the tweeters.

    so to summarize:
    -it's definitely NOT the actual tweeters which aren't working.
    -it's definitely NOT the receiver as I've changed it out.
    -the bridges ARE in place, but even with the top set of plugs connected I still have no tweeter sound.

    hope that helps eliminat a few variables.
  • Dennis Gardner
    Dennis Gardner Posts: 4,860
    edited July 2014
    If the tweeters aren't blown, then it must be an issue with your crossover, or wiring within the speaker. You have performed the easiest tests. It is rare for both speakers to go out at the same time.
    HT Optoma HD25 LV on 80" DIY Screen, Anthem MRX 300 Receiver, Pioneer Elite BDP 51FD Polk CS350LS, Polk SDA1C, Polk FX300, Polk RT55, Dual EBS Adire Shiva 320watt tuned to 17hz, ICs-DIY Twisted Prs, Speaker-Raymond Cable

    2 Channel Thorens TD 318 Grado ZF1, SACD/CD Marantz 8260, Soundstream/Krell DAC1, Audio Mirror PP1, Odyssey Stratos, ADS L-1290, ICs-DIY Twisted , Speaker-Raymond Cable
  • F1nut
    F1nut Posts: 49,708
    edited July 2014
    Replace the 5 watt resistors in the high frequency circuit regardless of how they look. Use Mills 12 watt of the proper ohm value
    Political Correctness'.........defined

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  • tonyb
    tonyb Posts: 32,902
    edited July 2014
    alexio wrote: »
    I have two Lsi15 towers and and an LsiC center... had been running these at very moderate volume on a $500 yamaha receiver (not sure of model as I don't have it anymore)..

    That's your problem right there. That entry level receiver can't drive 4 ohm speakers. You most likely toasted something in the crossover. Maybe open up the back and take a peek, see if anything is burned up on the crossover.
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  • alexio
    alexio Posts: 5
    edited July 2014
    got in touch with Polk, and it looks like I'll be ordering some crossovers to replace mine, $70 each sounds reasonable.

    my problem now is that the wires are soldered, to the crossover, which means that they need to be unclipped from the speakers ttthemselves. This wouldn't be an issue except I don't know how I would thread the wires back UP to the tweeter and the drivers at the top of the speaker... when I pull on them the feel VERY snug... and I imagine there is probabaly a barrier inbetwen the top and bottom of the speaker.

    anyone have any idea how the LSI are constructed, and how one would go about dealing with the crossover replacement?

    thank you again.
  • F1nut
    F1nut Posts: 49,708
    edited July 2014
    You don't need new crossovers. You need to replace the 5 watt resistor in the high frequency circuit with a 12 watt Mills. Replacing the entire crossover will not prevent the failure from happening again.
    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

  • alexio
    alexio Posts: 5
    edited July 2014
    F1nut wrote: »
    You don't need new crossovers. You need to replace the 5 watt resistor in the high frequency circuit with a 12 watt Mills. Replacing the entire crossover will not prevent the failure from happening again.

    a 12 watt Mills?.. ok, is this it? http://www.parts-express.com/mills-15-ohm-12w-non-inductive-resistor--005-15

    I'm finding different ohm ones, different impedance I believe that is? is it the 10 or the 15 ohm?
  • F1nut
    F1nut Posts: 49,708
    edited July 2014
    No, you need a 2 ohm, 12 watt Mills. This resistor location is marked R1 on the board. Order from http://www.soniccraft.com/

    You do own a soldering gun, yes?

    I will not guarantee 100% that this will fix your problem, but it is a well documented issue with the LSi's and much cheaper than replacing the boards. In your case, trying to drive 4 ohm speakers with an AVR that isn't rated to do so would easily cause clipping (distortion), which will overheat the resistor causing failure. I'm actually surprised you didn't cook the AVR.

    Just in case, if you do actually have to replace the crossovers simply desolder the wires at the board marking which goes where. That way you don't have to pull or feed wire.
    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

  • roadmap
    roadmap Posts: 2
    edited July 2014
    i ordered new crossovers for my csi3 center channel under warrenty my trouble is trying to run my rti12 that can handle the high volume but not the csi3 would changing mine (resister and capasitor) kep me from over heating the board i just posted a question on this i do not want to spend 1,000 on a 2 channel power supply. my onkyo 818 does just fine. other speakers center and 2 bookshelf, infinity no matter what abuse i put to them they keep on, keep on.....

    p.s. the main drivers not the tweeter on mine is going out always just one, the same one
    F1nut wrote: »
    You don't need new crossovers. You need to replace the 5 watt resistor in the high frequency circuit with a 12 watt Mills. Replacing the entire crossover will not prevent the failure from happening again.
  • tonyb
    tonyb Posts: 32,902
    edited July 2014
    Nothing is going to keep you from frying your speaker if you can't get the sticky fingers on the volume under control. That's the bottom line.
    HT SYSTEM-
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  • F1nut
    F1nut Posts: 49,708
    edited July 2014
    roadmap wrote: »
    i ordered new crossovers for my csi3 center channel under warrenty my trouble is trying to run my rti12 that can handle the high volume but not the csi3 would changing mine (resister and capasitor) kep me from over heating the board i just posted a question on this i do not want to spend 1,000 on a 2 channel power supply. my onkyo 818 does just fine. other speakers center and 2 bookshelf, infinity no matter what abuse i put to them they keep on, keep on.....

    p.s. the main drivers not the tweeter on mine is going out always just one, the same one

    That's a small center to run with the RTi12's. I'm guessing you are running too hot trying to keep up with the RTi12's. You need to dial it down in the calibration program or get a bigger center.
    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

  • tonyb
    tonyb Posts: 32,902
    edited July 2014
    F1nut wrote: »
    That's a small center to run with the RTi12's. I'm guessing you are running too hot trying to keep up with the RTi12's. You need to dial it down in the calibration program or get a bigger center.

    Good advice there. I might add that you don't need to spend a thousand bucks for a 2 channel amp. Half that would suffice. The 12's really need an amp anyway to sound their best. At higher volumes, that receiver is working overtime, take some stress off and invest 500 bucks for a good amp on the used market. A bigger center speaker and a 3 channel amp would be ideal though.
    HT SYSTEM-
    Sony 850c 4k
    Pioneer elite vhx 21
    Sony 4k BRP
    SVS SB-2000
    Polk Sig. 20's
    Polk FX500 surrounds

    Cables-
    Acoustic zen Satori speaker cables
    Acoustic zen Matrix 2 IC's
    Wireworld eclipse 7 ic's
    Audio metallurgy ga-o digital cable

    Kitchen

    Sonos zp90
    Grant Fidelity tube dac
    B&k 1420
    lsi 9's
  • alexio
    alexio Posts: 5
    edited July 2014
    Big thank you to all those who provided advice in this thread. This morning we were able to quite easily replace the resistor with the Mills units suggested, and my speakers are back to their glorious sounding selves again. Here is a picture as reference for others looking to undertake this minor repair.
  • F1nut
    F1nut Posts: 49,708
    edited July 2014
    Good, glad that worked out. Keep in mind that the 12 watt resistor will take more heat than the original 5 watt, so if you keep driving your speakers with the same AVR the next time it will likely take out the tweeters.
    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

  • Highnote
    Highnote Posts: 3
    Hi all, I have some Mills resistors on the way. My left crossover seems to be affected. One question I have is doesn't using the bi-amping feature of the LSi15 help this problem if the amplifier supports bi-amping?

    I am using a Pioneer Elite VSX-52. Any opinions if this amplifier has enough power for these speakers?
  • F1nut
    F1nut Posts: 49,708
    So, you have an AVR not an amplifier. As such you cannot bi-amp with an AVR because all those amp channels share the same power supply. In fact, the more amp channels you use means the power supply provides less power per amp channel.

    In addition, those speakers are 4 ohm nominal and I do not believe the AVR is rated to drive less than 8 ohm nominal speakers. You need a separate power amplifier to properly drive those speakers.
    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

  • tonyb
    tonyb Posts: 32,902
    Ditto the above, and the insufficient power is why your toasting crossovers/tweeters..
    HT SYSTEM-
    Sony 850c 4k
    Pioneer elite vhx 21
    Sony 4k BRP
    SVS SB-2000
    Polk Sig. 20's
    Polk FX500 surrounds

    Cables-
    Acoustic zen Satori speaker cables
    Acoustic zen Matrix 2 IC's
    Wireworld eclipse 7 ic's
    Audio metallurgy ga-o digital cable

    Kitchen

    Sonos zp90
    Grant Fidelity tube dac
    B&k 1420
    lsi 9's
  • K_M
    K_M Posts: 1,627
    edited March 2019

    alexio wrote: »
    Big thank you to all those who provided advice in this thread. This morning we were able to quite easily replace the resistor with the Mills units suggested, and my speakers are back to their glorious sounding selves again. Here is a picture as reference for others looking to undertake this minor repair.

    How loud are you playing your speakers, and do you know what distortion sounds like?
    Do you know how it sounds when an amp is over driven?

    To possibly help avoid this issue in the future with any amp.
    Post edited by K_M on
  • Highnote
    Highnote Posts: 3
    Yea, the 5W 2-ohm resistor was toast. Replaced with the Mills and tweeter is working again. Thanks for your comments about AVR drawing from a common amp and not really a separate amp when bi-amping. I have a Haffler DH 500 that will feed these beasts. Hopefully the preamp outputs from my AVR will attenuate the inputs when I turn the AVR volume down with the remote. Now I need a remote-controlled power strip so I can shut off the Haffler with my automation. I will report back how it goes.
  • Highnote
    Highnote Posts: 3
    kovyh04tboo2.jpg

    Here is the fried resistor. Haffler DH500 works well.
  • F1nut
    F1nut Posts: 49,708
    Thanks for letting us know you got things fixed up.
    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

  • The Doors
    The Doors Posts: 21
    Does anyone know what a good replacement tweeter for the LSi15's would be from Parts Express?
  • F1nut
    F1nut Posts: 49,708
    The Doors wrote: »
    Does anyone know what a good replacement tweeter for the LSi15's would be from Parts Express?

    NONE!
    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

  • stevep
    stevep Posts: 327
    F1nut wrote: »
    The Doors wrote: »
    Does anyone know what a good replacement tweeter for the LSi15's would be from Parts Express?

    NONE!

    Really? This wouldn't work?

    https://www.parts-express.com/mills-2-ohm-12w-non-inductive-resistor--005-2
  • pitdogg2
    pitdogg2 Posts: 24,477
    stevep wrote: »
    F1nut wrote: »
    The Doors wrote: »
    Does anyone know what a good replacement tweeter for the LSi15's would be from Parts Express?

    NONE!

    Really? This wouldn't work?

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

    replacement tweeter not resistor Steve. Of course he may need some resistors so they may have some if the ohm value is correct.
  • VR3
    VR3 Posts: 27,966
    The xt25 works, just have to swap the faceplate, not 110% but close enough for most people
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • VR3
    VR3 Posts: 27,966
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • stevep
    stevep Posts: 327
    pitdogg2 wrote: »

    replacement tweeter not resistor Steve.

    Thanks, I knew I missed a turn in this thread along the way.
  • The Doors
    The Doors Posts: 21
    I'm just looking for spare 'parts' for the LSi15's if needed. Thanks for the input everyone.