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Sub Platforms

Discussion in 'Subwoofers' started by niceguy235uk, Sep 3, 2005.

  1. niceguy235uk

    niceguy235uk
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    Even tho i have a solid concrete floor with not much carpet, does anyone think i would benefit by placing the subs on a platform of, say, MDF?

    Your opinions appreciated
     
  2. chris

    chris
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    I doubt if a piece of MDF would do.....
    But you could try these's .

    Made a huge difference to my duel sub setup.
     
  3. Ian J

    Ian J
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    According the independent review conducted by Secrets of Home Theater here the Gramma made hardly any difference when used on a concrete floor although they did notice a more perceptible difference when used on a suspended wooden floor.

    Anyone interested in such a device would do worse than check out the "Kill Vibe" subwoofer isolation platform being sold by Acousti Pro in the powerbuy forum here as it is rumoured to work better than the Gramma as well as being cheaper.
     
  4. chris

    chris
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    I've also got concrete floors and it made quite a big difference here.
    The whole house no longer shakes....
    Only the living room now.. :thumbsup:
     
  5. Nimby

    Nimby
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    I'm sure you're right. The question is why? :)

    My whole house shakes to my sub's output. It does this by acoustic pressure waves propogated from the cone and port travelling through the airspace indoors producing sympathetic vibration in suitable internal structures.

    The structural resonances due to direct transmission of vibrations from the bottom of the enclosure resting on my comparitively flimsy floorboards are absolutely minuscule in comparison.

    I note that Kill-Vibe (in the linked thread) lists no noise reduction at the frequencies we are most interested in with subwoofers. 125Hz is usually at the absolute limit of most subwoofers output on progamme material. Ignoring, for the sake of argument, the small overhang beyond the usual filter roll-off point.

    Nimby
     
  6. chris

    chris
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    Exactly...... :confused:
     
  7. Nimby

    Nimby
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    Well I'm glad we've got that sorted out. :D

    Nimby
     
  8. binbag

    binbag
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    I've been doing some boning up on acoustics at Audioholics. Patrick Hart in his article on Room Acoustics: Isolation & Noise Control says:

    NIC (Noise Isolation Class) and STC (Sound Transmission Class) are not defined below 125Hz

    The one thing I would not want in an Isolation platform is noise reduction.
     
  9. mattym

    mattym
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    the killvibe is very similar to the gramma, i have been messing around with materials to develop a product like this for a few months and the basic construction is very simple. If the testing is succesful there will be another product in the powerbuy
     
  10. Nimby

    Nimby
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    Why not? A combination of compliance and resistance would seem a logical requirement to isolate conductive noise transmission of a subwoofer from the floor it stands on. I don't follow Audioholics. What have I missed? :)
     
  11. binbag

    binbag
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    Noise Reduction is defined in the same article as the difference in sound levels from one enclosure to another - usually between rooms. I don't need this as I am only in the listening room. The result I am after is the ability to put more bass into the room without affecting it by vibration whilst maintaining the quality of the sound from the subwoofer.
     
  12. laalves

    laalves
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    Not particularly worried with vibration transmission to my living room floor (I would say this maybe a big concern for a live gig's stage..., which is basically a hollow structure), I bought four Auralex Mopads to put under my Revel B15a, and four more to put under my TAG Calliopes and Bass modules.

    The idea is quite simply to stick all the spikes into the Mopads, so that i can easily move the things around, without scratching the wooden floor....

    Luis
     

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