Rumble from TT

Discussion in 'Turntables' started by MER71, Jun 12, 2018.

  1. MER71

    MER71 Super Member

    I noticed the rumble from the TT. The noticed it with my Vandersteens 2c and Polk SDA 1A. They say good speakers will reveal your flaws. Any suggestions? I am using a Realistic Lab-500. Thank you in advance.
     

     

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  2. marcmorin

    marcmorin AK Subscriber Subscriber

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    could be the table bearings need addressed, could be table noise is being amplified and reflected back into the table from the stand its on. could be just an energy loop through the table itself from a culmination of the motor noise, bearing noise, base noise reflecting all that. Etc.
     
  3. Poinzy

    Poinzy Super Member

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    Deleted by poster, 6/14. Reason: We can't seem to settle on a definition of "rumble".
     
    Last edited: Jun 14, 2018
  4. Grenadeslio

    Grenadeslio Super Member

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    Could also be in the vinyl, does it seem most prevalent between songs?
     
  5. maxhifi

    maxhifi AK Subscriber Subscriber

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    Is the sub level turned up too high? Maybe try a different turntable and see if the results are similar. Also, it could be acoustic feedback if the turntable is too close to the sub.
     
  6. Van_Isle

    Van_Isle AK Subscriber Subscriber

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    It's quite possible that (I'm assuming) the 'lubricated for life' direct drive motor in the turntable is in dire need of lubrication!

    Also, it's been reported that the compliance of the original cart results in a resonant frequency below 5Hz, which will exaggerate the effect of record warp and turntable rumble. You might want to try a much less compliant cart on that table or locate a n95ej stylus for the original cart. If you go with a different cartridge, you'll have to use a light headshell. The original combo headshell / cart was only 10.7g ... you don't really want that counterweight wagging around at the extreme end of the tonearm stub (and probably hitting the dustcover). You could also rig-up an auxiliary counterweight.

    Here's a good thread on the subject of the LAB 500: http://audiokarma.org/forums/index.php?threads/my-rebuilt-fully-restored-realistic-lab-500.481589/
     

     

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  7. MER71

    MER71 Super Member

    So start with speaker placement? How far away should they ideally be?
     
  8. MER71

    MER71 Super Member

    The rumble is the sound of the stylus in the groove. I notice the rumble defines warped vinyl.
     
  9. Van_Isle

    Van_Isle AK Subscriber Subscriber

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    Not really .... rumble is low frequency noise generated by the turntable ... typically the bearing, belt, motor, pulley, belt, etc. Some records may actually have rumble existing in the master tapes ... perhaps from a poor bearing in the cutter.

    I think the general concepts have been defined above. But what I was saying previously, about the stock cartridge is pretty key to your issue, as far as I'm concerned. Read this (although there are, I believe, some issues with the inputs used in the calculations presented): http://www.theanalogdept.com/cartridge___arm_matching.htm If your cartridge / tonearm combination results in that frequency being in the range of rumble .... or record warp .... or footfall ... you'll hear it. And as I was saying, it looks like the stock cartridge does just that.

    In terms of speaker placement ... don't have the speakers on the opposite side of the room facing the turntable. Don't have the turntable sitting out in front of the speakers. Take the dust cover of the turntable when it is in use (or at least close the dustcover) In other words don't do anything that promotes the stylus picking up vibrations from the speakers. How far away? Usually it isn't an issue, because the general rule of thumb is the speakers and you, the listener, should form an equilateral triangle. So how far do you sit away from the speakers ... 10 feet? 6 feet? So how far away is the speaker from the components? 2 to 4 feet? But of course set-ups quite often are not ideal. I have a long low, long stand that has 2 turntables, 2 amps, etc. on it, so my turntables sit to each side of my stand with speakers right next to them. I've had some issues with woofers 'pumping' when cycling turntables / cartridges through the setup but generally, with good matches, I don't have any issues.
     

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