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Subsonic filter?

Discussion in 'Subwoofers' started by nathan_silly, Apr 21, 2003.

  1. nathan_silly

    nathan_silly
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    I'm thinking of adding a subsonic filter to my ported sub and remove the frequencies below the tuned port (doing this is supposed to stop any chuffing/cone bottoming out)

    Any decent makes & links?

    Something in-line with phono input, phono output would be ideal, with variable subsonic filters, say 12hz-25hz.

    Thanks
     
  2. nathan_silly

    nathan_silly
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  3. dunkyboy

    dunkyboy
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    Good point, well made.

    Dunc
     
  4. EvilMudge

    EvilMudge
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    Nathan, I think that's the most profound thing you've ever said.:clap:
     
  5. nathan_silly

    nathan_silly
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    Has no-one used a subsonic filter before?:(
     
  6. EvilMudge

    EvilMudge
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    Yes, I've built one from scratch - the end result, it adds more crap into the signal chain, so in some ways the benefits are outweighed by the negatives. However, high-passing before the gain stage always helps with dynamics. Just in this case it wasn't worth the effort.
     
  7. nathan_silly

    nathan_silly
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    OK cheers.

    So I take it using high-level (speaker) subsonic filter would be better than using low-level? (phono)

    Just seems a good idea to remove the frequencies that the sub can't reproduce.

    I'll be using the Subwoofer out from my processor.
     
  8. EvilMudge

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    Nathan,
    The one I was forced to build ;) was an active design, so it worked best at line level, it also avoided most of the problems of passive filters. However there was high frequency noise in the signal because of the poor Op amps I used.
    BUT if you feed a sub this way, then the crossover in the sub will filter the out of band noise. So it should work. Avoid passive subsonic filters though.
     
  9. Sunday Ironfoot

    Sunday Ironfoot
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    Was that your attempt at hiding a bump? :smoke:
     
  10. Steve.EX

    Steve.EX
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    Nathan

    Why not use a BFD?
    Simply set a (peak) filter to around 20 ish hz, set the Q to very wide and run off the gain to whatever. (i.e -15db?).

    Steve.


    P.S 25HZ??????? Why, thats practically treble!!
     

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