How to stop the ringing

Discussion in 'Home Theater Projects' started by Russell R, Dec 30, 2003.

  1. Russell R

    Russell R Stunt Coordinator

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    Hello,
    I have been listening to my 142.5|21.5hz Shiva and notice that there is ringing in the enclosure. It is a 14" diameter PVC pipe. What can I use to deadon the enclosure? Egg crate foam or polyfill batting lining the enclosure? How will this affect the overall design?

    I placed a Nerf Football in the port to create a sealed sub and I did not notice the ringing. So, what does this mean?

    Does sonotube or concrete forms made out of cardboard ring? There is a thread about group delay. Could this be a function of group delay?

    Thanks,
    Russ

    A sealed sub with stuffing does sound good... Maybe a Sealed Tempest or Maelstrom...

    I am lik
     
  2. TimForman

    TimForman Supporting Actor

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    Me thinks you need to damp that enclosure. It could be done from the inside or the outside. Consider the asphalt based damping sheets available from Parts Express on the inside and/or indoor/outdoor carpeting on the outside. I've built a Shiva-based Sonosub and an AV8 based tube, a little different from your design, yet I've never experienced ringing. I have experienced resonance in a ported Sonotube design. Perhaps the stiffness of the PVC contributes to that, being a material that may get into sympathetic vibration with some of the higher harmonics.
     
  3. Russell R

    Russell R Stunt Coordinator

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    I had some batting lying around the house and I glued it to the walls of the tube. This fixed the ringing. Just 1/2" of polyfil on the walls made all the difference in the world. I am thinking about changing my tune from 21.5 to 18.1hz for testing purposes. This is the EBS tune anyway.



    Thanks,
    Russ
     

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