Smoked drivers on RTA 11t’s?

Marantz SR-7005, PS Audio 200C, RTA-11t’s.

Just started up my system a few minutes ago. When I turned the amp on the normal intitial relay pop was quieter. Noticed the volume output was low relative to the setting. I paused the music. As I looked closer and one the drivers they appear to be bulging out with no signal to the amp. I killed the amp power quickly and then unplugged everything. My integrated is driving my center channel fine.

Tweeters seem fine, not much of anything coming from the drivers in either speaker.

Any thoughts?

Thanks,
Ian

Comments

  • DaveHo
    DaveHo Posts: 3,536
    Sounds like the amp is sending DC to the speakers. Woofers are now toasted. Time to get the amp serviced.
  • F1nut
    F1nut Posts: 50,647
    Ian, the Marantz is an AVR, not an integrated. Anyway, I suspect your PS Audio amp is the problem. Remove it and connect your speakers directly to the AVR. If they work properly you know the amp is bad.
    Political Correctness'.........defined

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  • F1nut wrote: »
    Ian, the Marantz is an AVR, not an integrated. Anyway, I suspect your PS Audio amp is the problem. Remove it and connect your speakers directly to the AVR. If they work properly you know the amp is bad.


    Just hooked up the mains to my AVR. Speakers seem to be intact.


    Thanks for the advice. Now it’s onto the amp, that was supposedly service before I bought it.
  • Now I feel really stupid. The volume on my source (Xbox one), was set very low by me yesterday. Hence the difficult in producing sound. As for the drivers moving outward, what would cause that?

    I think the amp is fine, I have to set everything back and test it still.
  • FestYboy
    FestYboy Posts: 3,861
    DC current will do that so be cautious.
  • Tony M
    Tony M Posts: 11,160
    Thank God for the easy fixes. ;)

    Speakers moving outward was answered by @DaveHo. ;)
    Most people just listen to music and watch movies. I EXPERIENCE them.
  • DaveHo
    DaveHo Posts: 3,536
    Do you have a multimeter? If so, you can test the amp to see if it's sending DC. Plug in and turn on the amp with nothing connected to it. Let it sit for 10 minutes or so to stabilize. Set your multimeter to measure DC voltage. If you are getting more than +/- 50 mV, you have a problem. Don't do this with a tube amp.
  • DaveHo wrote: »
    Do you have a multimeter? If so, you can test the amp to see if it's sending DC. Plug in and turn on the amp with nothing connected to it. Let it sit for 10 minutes or so to stabilize. Set your multimeter to measure DC voltage. If you are getting more than +/- 50 mV, you have a problem. Don't do this with a tube amp.


    I will give a shot later tonight. Thanks for the suggestion.
  • DaveHo
    DaveHo Posts: 3,536
    Just for clarity sake, you want to measure between the pos and neg terminals of each channels speaker outputs.
  • The multimeter I have only has a resolution down to .1 V DC. I am not getting any reading. 50 mV is .05 V. Do you think I am in the clear? I know I am less than 100 mV if I am not getting a reading.
  • DaveHo
    DaveHo Posts: 3,536
    Less than 100mV shouldn't fry anything, but above 50mV will likely cause some level of audible distortion. If you're going to dabble in vintage gear, it wouldn't be a bad idea to pick up another meter. I never connect speakers to a new amp without checking DC offset first.
  • Any recommendations on a decent multimeter that has that type of resolution for DC voltage? Everything I am seeing seems to be .1 V or higher.
  • DaveHo
    DaveHo Posts: 3,536
    A quick Amazon search turns up a wide variety of choices. Here is one example which reads in terms of mV for not a lot of money. I have no personal experience with it. Myself, I have a Micronta branded meter I purchased at Radio Shack many years ago.

    https://amazon.com/dp/B01N9QW620?ref=emc_b_5_i