TSi500s just died

Jokanuk
Jokanuk Posts: 5
in Troubleshooting
I've had a set of TSi500s for many years and they have been fantastic, I expected them to be with me for life. I recently connected a 45W vintage 1978 JVC amplifier to them and have been listening for a few weeks with no issues. Then one morning I switched on my system and got nothing from the speakers but a few tinny sounds from the tweeters. I tested them on two other amplifiers but no luck. I'm nearly a senior citizen so I never blast the volume. Curiously, they were working great when I shut things off the previous day. What have I done to my speakers? I put in a request to Polk but haven't heard back yet, just wondering what forum users might be able to tell me.
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Comments

  • [Deleted User]
    [Deleted User] Posts: 7,658
    While not a certainty it is possible the JVC has damaged your speakers due to direct current (DC) being fed to the speakers. This would cause the voice coils in the bass/mid range drivers of your speakers to become defective. You would need to replace them and have the JVC checked out for DC leakage.
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  • Jokanuk
    Jokanuk Posts: 5
    KennethSwauger wrote: »
    While not a certainty it is possible the JVC has damaged your speakers due to direct current (DC) being fed to the speakers. This would cause the voice coils in the bass/mid range drivers of your speakers to become defective. You would need to replace them and have the JVC checked out for DC leakage.
    Thank you for your answer. I have no expertise with speakers, but it seems odd to me that all 8 drivers would fail simultaneously. However I can understand if there was a spike or surge when switching on the amp, they could all fail at once. It's sounding expensive in any case. I will get them checked out to see if they are worth fixing.

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  • [Deleted User]
    [Deleted User] Posts: 7,658
    I agree, it does seem a bit extreme. If you've owned them for less than five years, Polk should replace any damaged components under warranty. Does anybody use your system when you're not at home? Has the house AC gone off recently? If you've connected your speaker wire to the upper set of binding posts are the binding post jumper plates firmly attached?
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  • Jokanuk
    Jokanuk Posts: 5
    I have owned these for 6 years so they are off warranty. No one else uses my system, and I don't think there was a power outage. I have never changed the binding post connections from new. I have heard back from Polk asking me to test the drivers individually, and if they all work it points to the crossover as the problem. I will try that tonight.
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  • DaveHo
    DaveHo Posts: 3,513
    Do you own a multi-meter? I would test the JVC receiver output before connecting any other speakers to it. Here's a guide: https://wikihow.com/Measure-DC-Offset
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  • Jokanuk
    Jokanuk Posts: 5
    Thanks, I will try that. I took two of the drivers out of one tower and tested them directly from an amp and they both worked just fine. I guess that points to the crossover board as the fail point. Wondering what component could have failed on the crossovers for both towers at the same time.
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  • Jokanuk
    Jokanuk Posts: 5
    DaveHo wrote: »
    Do you own a multi-meter? I would test the JVC receiver output before connecting any other speakers to it. Here's a guide: https://wikihow.com/Measure-DC-Offset
    I measured the DC offset from my JVC amp according the guide. Right at 10mV on each channel. Apparently an offset between 0 and 20mV is very good per the guide. Now I'm more baffled than ever as to what caused this failure.
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