Anything Other Than Phase Responsible For 10-12db Drop At 80Hz?

Discussion in 'Speakers & Subwoofers' started by James Edward, Jun 25, 2003.

  1. James Edward

    James Edward Supporting Actor

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    I am able to equalize my sub to within 3db's of flat from 20hz-50hz. At 63hz, it begins to fall off, and at 80hz and 100hz, it is down by about 12db.

    Sub phase does nothing to correct this situation- would reversing polarity of the 3 front speakers possibly help? Or is that simply the same as changing the sub's polarity because they are interactive?

    Sub is in front with the other speakers, and has continuously variable 180 degree phase adjustment. Receiver currently set for 80Hz crossover.

    I am asking before doing because the speakers are bi-wired and my wife has to do the switching, because of recent back surgery. So I don't want her doing it if the consensus is it won't do any good...

    All thoughts appreciated. Thank you.
     
  2. Lee Carbray

    Lee Carbray Second Unit

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    James try unhooking the mains and checking the response of just the sub. It is still falls off then no phase issue, and most likely a room issue. If it stays flat the you possibly have a phase issue.
     
  3. Lee Bailey

    Lee Bailey Second Unit

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    James, are you bypassing the crossover in the sub? If it cannot be bypassed, then set it to its highest crossover point.
     
  4. Lewis Besze

    Lewis Besze Producer

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    It's the room, you either have to move the sub or you have to live with it.It can't be EQ'd
     
  5. EricSm

    EricSm Stunt Coordinator

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    Don't feel alone. I have the same issue. Except mine is more like a -15 db drop at that frequency with the sub. Hopefully with my speakers crossed over at 80hz it's not too much of an issue... I did find that by moving my sub to the opposite corner in the room helped cut that db drop in half, and it also smoothed out some of the frequency response. You may wanna look into placement options.
     
  6. James Edward

    James Edward Supporting Actor

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    I will try out the suggestions and report back tomorrow.
    Thanks a lot...
     
  7. Kevin C Brown

    Kevin C Brown Producer

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    I agree, probably not phase. The max swing I get in phase vs out of phase is only 6 - 7 dB. You probably have a room node problem.
     
  8. RichardHOS

    RichardHOS Second Unit

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    Probably room mode as pointed out above.
     

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