Bass Boost when calculating port length

Discussion in 'Home Theater Projects' started by Russell R, Nov 2, 2003.

  1. Russell R

    Russell R Stunt Coordinator

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    Hello,
    I am wondering if anyone here has tuned their subs with a little bass boost? Currently, I have a 142.5L with 21.5hz tuned flare and will try a 25hz tune, which will raise my 30hz region ~2db. Just playing around. Also, according to WinISD, the port speed should be decreased. This may help on the little port noise that I hear from time to time.

    Your thoughts?

    Thanks,
    Russ
    RODERPLEX
     
  2. GrahamT

    GrahamT Supporting Actor

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    I may be wrong but I dont think that the PE amp has a SS filter. Maybe raising the tune could increase the chances of unloading the driver below the tuning frequency? I agree port noise is annoying but have you considered getting a bigger diameter port to lower air speed? Also maybe I am mistaken again but I think that PE put bass boost in the amp. If not you can probably do it but swapping and soldering some resistors. Are you RuSsMaN?
     
  3. Russell R

    Russell R Stunt Coordinator

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    No I am not Russman.

    The PE250 plate that I have does not have bass boost. I never thought about unloading the driver at a higher Fs.

    Thanks,
    Russ
     
  4. GrahamT

    GrahamT Supporting Actor

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    The Fs is the speaker's free air resonance freq. I think you mean Qtc. If you dont have the rumble filter the driver could unload below the tune as I said before. I assume you are looking for more mid bass punch. Maybe you could build another Shiva in a high Q sealed box. Just a suggestion.
     

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